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  #16  
Old 02-23-2016, 08:47 PM
ferrarif1fan

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It's been said that a properly engineered .22 firing pin should not contact the breech on dry fire. But you tend to find that out by realizing, like you did, that your breech face is peened.

If the shells drop in fine and eject fine, you'd probably be okay just leaving it as is. On my Anschutz 54 target rifle, I accidentally dry fired ONCE and peened the breech face enough that I has having issued loading and extracting rounds. So, I tried something I'd read once. I found a round punch with a long, tapered nose on it. I carefully inserted it in the chamber and marked where it would contact the edge of the chamber. I then polished that portion of the punch to a mirror finish. With the rifle positioned so that the barrel was perfectly vertical, I slowly lowered the punch into the chamber. When it made contact, I held it perfectly vertical and gave it a very light tap with a tiny ball peen hammer I have. I then withdrew the punch and attempted to load a target .22 round into the chamber. I continued this process of lightly tapping the punch until the round loaded fully into the chamber. Never had another problem, and certainly never accidentally dry fired my rifle.

If I'd not been having any loading or extraction issues like you, I probably wouldn't have attempted the repair. But it was causing me problems in matches.
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  #17  
Old 02-23-2016, 08:55 PM
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Quote:
Originally Posted by labratt104 View Post
My Buckmark has the polymer insert. I disassembled it for cleaning when I installed the target hammer from VQ. The firing pin had an elongated hole through which the firing pin retaining pin fits. I believe this hole prevents the firing pin from moving too far forward or back, or at least in theory.

I would think that any polymer/plastic could be "stretched" just far enough after many repeated impacts of the hammer on the firing pin, pushing the firing pin retaining pin forward enough to allow the firing pin to contact the breech face.

Or, I could be full of old rusty Marlin parts, or the organic equivalent thereof.
I think you're on to something here with the polymer being the most easily deformed material in the system

Quote:
Originally Posted by SavvySlug9 View Post
Instead of snap caps you can use:
http://www.homedepot.com/p/Crown-Bol...4-8+crown+bolt

#4-8 x 7/8 in. Yellow Ribbed Plastic Anchors (100-Piece)
I purchased this last week from Home Depot, $4. I can reuse them many times, they arent brittle. I can load up to 2x in my CZ 22lr 5 round mag.
I have no problem with the Pachmayr dummy loads, I have hundreds as I use them for Silhouette dry fire practice in my CZ452 Vamint. It's another rifle that is "safe" to dry fire empty, but it's such an outstandingly accurate rifle that I don't want to risk damaging it. The main advantage to the Pachmayrs is their ability to work in and feed from a magazine.

Quote:
Originally Posted by gmd1950 View Post
I've used these for about 10 years, and the next larger size work well for .22wmr and .17hmr too.
Thanks for the info- See above.

Quote:
Originally Posted by Jim_WY View Post
This has always been my belief.



Your question of "What has changed" is exactly my question, too.

On my Buck Mark, the firing pin is not long enough to ding the breech face.

When firing the gun, the hammer presses the back of the firing pin, and the nose of the firing pin presses into the case rim of the round.

The firing pin is long enough that as it crunches the brass of the case rim, it also decelerates the hammer to a stop before the hammer hits the back of the slide.

The firing pin transfers the force of the hammer directly into the case rim. It is not a striker-fired gun.

The firing pin only needs to be long enough to make sure that it holds the hammer away from the back of the slide at the end of a successful strike on a round. And since the firing pin doesn't cut all the way through the case rim (which would be dangerous, of course), we know that the nose of the firing pin never needs to reach out far enough to touch the breech face under normal shooting conditions.

It then follows that there's a range of firing pin length that will fully transfer the hammer's force, yet not be so long that the hammer can drive the firing pin into the breech face. But this may vary slightly from gun to gun depending on the dimension of the slide between its back face and the front where it touches the breech when closed.

But, when dry firing with nothing in the chamber, the firing pin will be able to fly forward even further than how far the hammer can actually push it directly, due to the inertia of the firing pin itself.

That's where the pin and the oblong slot in the firing pin come into play.

Of course, the main reason for the slot in the firing pin and the pin that goes through the plastic block is simply to hold the firing pin captive so it doesn't fall out and get lost.

But if things are ideal, then it should also catch the firing pin just short of touching the breech face, and prevent it from being able to even "kiss" the breech during a dry fire.

That's what I think is the ideal situation.


A few other thoughts:

I wonder how much of a peen just the inertia of the firing pin would be able to make. Surely, the low mass of the firing pin will limit the amount of energy it can transfer to the breech.

I don't like the idea of the hammer striking the back of the slide. So I don't like dry firing these guns even if the firing pin's length and the position of the oblong hole and the pin that holds it captive are such that it cannot fly forward and peen the breech face. And even when using a soft plastic thing, such as a drywall anchor, I can't help cringing a bit thinking of the firing pin entering the soft plastic easily and allowing the hammer to slam into the back of the slide. Maybe that's just needless worry, but I have to think that the design really intends for the brass case rim to decelerate the hammer and bring it to a stop just short of striking the slide-back.


The peen mark in your breech face looks fairly deep. I just don't know if the inertia of the firing pin would be enough to create that deep of a ding with just a few dry firings.

But a firing pin won't get longer! And the only explanation I can think of where something could wear and allow a gun that formerly couldn't peen to eventually become a "peener" is wear of the oblong hole in the firing pin, wear of the pin itself, or deformation of the plastic block.

And I actually think the plastic block might hold up better to that kind of continuing impact than a metal one would because it'll act like a buffer.

As you say, the mystery is why a non-peener has become a peener.

I do know that the new Buck Marks all seem to come from the factory with peened breech faces these days. Supposedly it's from the dry firing that takes place during assembly and testing. I don't like it, myself, but that's just me.

My BM doesn't peen. At least not yet! But with repeated dry firings, who knows? Maybe the firing pin's hole would "waller out" over time, or the plastic block or retention pin could wear.

I participated in a very long thread about this subject a while back, and posted a lot of photos showing what I'm talking about. The thread was started by a guy who got a new BM that was already peened right out of the box so badly that the chamber was distorted, and it wouldn't feed properly.

Looking at various new BMs at stores lately, I see peening on the breech faces of them all. I don't care for it, but whatcha gonna do?


Thats one thing I wonder- could the inertia be enough to peen the breech?

Agreed, But SOMETHING about the FP stop in MY rifle changed. I will list the possibilities at the end of this post.


Like it or not, it happens on more rimfires than not. Inspect all of yours and push on the back of the FP and see how deep it goes. Many of mine will go flush with the bolt surface and many will show contact marks from the hammer contacting the bolt. Both are hardened and made to take that impact. This causes no damage and is something I personally don't waste my time worrying over.

Thats my conundrum. I don't just want mine fixed, but want to understand WHAT CHANGED so I can prevent it from happening again. I have studied the system closely and will list the possible causes at the end of this post.
Mine was like yours- perfectly fine with no marks for 7-8 years and many thousands of rounds fired. Then, all of a sudden, I have a rather deep gouge with no warning or explanation as to how or why. I will say that you should watch yours closely.



Quote:
Originally Posted by aprilian View Post
1) if you don't like the idea of the plastic slowing down the firing pin enough, use the aluminum dry fire dummy loads.
2) theoretically, the FP spring slightly slows the FP as it moves towards the breech and round. a spring failure (or incorrect spring) might increase the tendency to have a dry fired FP hit the breech.
3) due to stacking tolerance on the parts, some FPs will be closer to the breech than others from the factory. Replacing a FP can also increase a tendency for dry fire breech marking as it is not worn (on both ends) as the previous piece was

Good luck
Plastic dummy loads do fine at protecting the breech, this happened BEFORE I started using them. I had dry fired it on an empty chamber many times at the end of a range session and after cleaning with no ill effects. I now know to protect it with dummy rounds, BUT I often let my friends and my kids shoot my guns. All of my .22s are safe to dry fire, except this one- and that's new. I can't be certain that others won't accidently drop the hammer on an empty chamber, so I want it fixed in a way that puts it back to where it was, safe to dry fire without worrying about damaging it. I don't know if the inertia is enough, but I'm more inclined to think that it's a direct impact with the momentum and force of the hammer and mainspring involved.

Quote:
Originally Posted by 27 Beck View Post
You can get the full FP assembly for $6.00 and change from Browning parts department. The source you mentioned is almost always 2x or more for same parts.

Also check out this tool if damage is more severe.
http://www.brownells.com/gunsmith-to...-prod8869.aspx
THANK YOU!!! I ordered 3 assemblies and a couple of disconnectors. Labratt104 came up witH the idea to work on the notch in the disconnector to take up the pre travel and I think he's right on. Mine already has the VQ Target hammer (installed AFTER the peening incedent, so NOT the cause) and I just ordered the TK Victory trigger. I plan to install that and work on tuning a disco next week.

Quote:
Originally Posted by GtrPlyr View Post
+1 on that!

And, while you're ordering, since it's flat rate shipping, pick up a couple of the little c-clips for the guide rod, a spare spring and few other little goodies that can come in handy, too.
Yep, I did. 2 disconnectors and 2 Recoil buffers ordered along with 3 of the $6 recoil assemblies. Thanks!

Quote:
Originally Posted by SGW Gunsmith View Post
The picture below shows a faint, "one-time" firing pin hit on a new Buckmark pistol. Same as yours. The only time I did not have a dry wall anchor in the chamber, so I'm thinking that the firing pin stop pin hole couldn't be worn, but it could be too long. Or, the overall length of the firing pin needs adjusting, as was suggested above.

Thanks for that, I'm still in the "diagnosis phase". While I agree that tuning the overall FP length is a potential fix, my FP length is not what changed, protrusion did.
I did NOT spill Viagra on my FP

Quote:
Originally Posted by Jim_WY View Post
For what it's worth, back in that other lengthy thread, a lot of this was discussed.

I will try to find a link to that thread.



Tabbed in.
And
Quote:
Originally Posted by Nolan View Post
Is this the magnum opus you were thinking about?

Has Browning fixed the peening problems yet?


Nolan
Thanks for the link, I read a lot of that thread and plan to read the rest later. Most of the discussion was about guns that came peened from the factory, and my situation is different as SOMETHING about my pistol changed to make this condition possible.

WHAT COULD CAUSE FP Protrusion to INCREASE in a 2001+ Buck Mark?

My thoughts:

What stops the FP on an EMPTY CHAMBER?

-The FP stop pin
-full detent of the FP into the rear of the bolt allowing the hammer to strike the bolt
-contact with the breech

So, what could CHANGE a gun to allow PEENING?

1) The FP stop hole in the FP itself has been beaten and worn from hammer strikes on an empty chamber, where the stop pin is contacting the FP. (I will need to measure my FP and compare to a new one)

2) The FP stop pin itself is deformed (not the case)

3) The hole in the plastic housing for the FP stop has been hogged/stretched out to allow further protrusion (not the case, pin fits tight)

4) The plastic housing itself has become compressed and allowed protrusion to increase.


My suspicion is that condition (1) or (4) is to blame...either the stop pin hole in the FP itself has elongated from abuse, taking hammer strikes without a brass rim to cushion the blow and stop the FP, or the plastic housing has deformed from taking a beating.

I will likely know much more when I get the new assemblies and can compare my old, worn parts to new ones.

I sincerely appreciate all the time and effort that you all put into answering this question.

I really do hope I get a solid answer to what I believe is the most salient question here...What Changed?

Respectfully,

DrGunner
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Last edited by DrGunner; 02-23-2016 at 08:59 PM.
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  #18  
Old 02-23-2016, 09:03 PM
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Quote:
Originally Posted by ferrarif1fan View Post
It's been said that a properly engineered .22 firing pin should not contact the breech on dry fire. But you tend to find that out by realizing, like you did, that your breech face is peened.

If the shells drop in fine and eject fine, you'd probably be okay just leaving it as is. On my Anschutz 54 target rifle, I accidentally dry fired ONCE and peened the breech face enough that I has having issued loading and extracting rounds. So, I tried something I'd read once. I found a round punch with a long, tapered nose on it. I carefully inserted it in the chamber and marked where it would contact the edge of the chamber. I then polished that portion of the punch to a mirror finish. With the rifle positioned so that the barrel was perfectly vertical, I slowly lowered the punch into the chamber. When it made contact, I held it perfectly vertical and gave it a very light tap with a tiny ball peen hammer I have. I then withdrew the punch and attempted to load a target .22 round into the chamber. I continued this process of lightly tapping the punch until the round loaded fully into the chamber. Never had another problem, and certainly never accidentally dry fired my rifle.

If I'd not been having any loading or extraction issues like you, I probably wouldn't have attempted the repair. But it was causing me problems in matches.
Thanks for that. So far, I've had no loading or extracting issues. A gravity fed round will seat and drop out without resistance and the chamber leaves no marks on the casings, so I've been lucky so far.

That said, leaving this gun in its current condition would likely result in a deeper gouge and further damage.

I plan on checking the breech face for level and polishing off any high spots, but leaving the chamber alone.

Thanks again, all-

DrGunner
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  #19  
Old 02-23-2016, 09:56 PM
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DrGunner this will not solve your mystery but is related and would seem to be the solution to prevent breech peening from dryfire on most any rimfire. Some guns have a small recess machined into the breech face to coincide with where the firing pin would make contact with the breech. This prevents a slight excess firing pin protrusion from causing damage to the chamber. I happened to have my Martini handy, I looked and it has the recess. I suppose it is still possible for an inertia firing pin, without a firing pin stop to move forward far enough and with enough force to strike the bottom of the recess but that seems pretty unlikely. Any thoughts here why this feature is not used on most guns? If just a couple of accidental dryfires (as opposed to repetitive "dryfire practice") can cause this kind of damage I would think the recess would be standard operating procedure.

Last edited by Patriotpappy; 02-23-2016 at 10:05 PM. Reason: added comments
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Old 02-23-2016, 10:23 PM
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Quote:
Originally Posted by Nolan View Post
Is this the magnum opus you were thinking about?

Has Browning fixed the peening problems yet?


Nolan
Nope. The one I'm referring to predates that one.

And man, you're right. It really is a Magnum Opus!!!

It's this one:

https://www.rimfirecentral.com/forums...d.php?t=354088

If someone is really really bored, they can read through that whole 300 post thread. I posted a lot of photos and thoughts about all of this into that thread.

Quote:
Originally Posted by Baklash View Post
That seems to be a very deep peen for as little dry firing as you describe, so it's definitely not due to dry fire. I've used the yellow dry wall anchors, but don't always have one handy. I recently made a thin plastic tag that I keep on my key ring. It's maybe the thickness of a credit card, probably a little less. It fits right into place when I need it.
I agree. That's a mighty deep peen for very little dry firing, particularly if the firing pin's inertia is all that's been involved.

I like the idea of the small piece of plastic on the keyring. That'd work a treat and you'd always have it with you.

Quote:
Originally Posted by ferrarif1fan View Post
It's been said that a properly engineered .22 firing pin should not contact the breech on dry fire. But you tend to find that out by realizing, like you did, that your breech face is peened.

If the shells drop in fine and eject fine, you'd probably be okay just leaving it as is. On my Anschutz 54 target rifle, I accidentally dry fired ONCE and peened the breech face enough that I has having issued loading and extracting rounds. So, I tried something I'd read once. I found a round punch with a long, tapered nose on it. I carefully inserted it in the chamber and marked where it would contact the edge of the chamber. I then polished that portion of the punch to a mirror finish. With the rifle positioned so that the barrel was perfectly vertical, I slowly lowered the punch into the chamber. When it made contact, I held it perfectly vertical and gave it a very light tap with a tiny ball peen hammer I have. I then withdrew the punch and attempted to load a target .22 round into the chamber. I continued this process of lightly tapping the punch until the round loaded fully into the chamber. Never had another problem, and certainly never accidentally dry fired my rifle.

If I'd not been having any loading or extraction issues like you, I probably wouldn't have attempted the repair. But it was causing me problems in matches.
You can buy what is called a "chamber ironing tool" to do what you describe. They're not horribly expensive.

Here's one example:

http://www.brownells.com/gunsmith-to...-prod8869.aspx

But I don't see anything wrong with the method you used, either.

Quote:
Originally Posted by DrGunner View Post
I think you're on to something here with the polymer being the most easily deformed material in the system

Thats one thing I wonder- could the inertia be enough to peen the breech?

Agreed, But SOMETHING about the FP stop in MY rifle changed. I will list the possibilities at the end of this post.

Like it or not, it happens on more rimfires than not. Inspect all of yours and push on the back of the FP and see how deep it goes. Many of mine will go flush with the bolt surface and many will show contact marks from the hammer contacting the bolt. Both are hardened and made to take that impact. This causes no damage and is something I personally don't waste my time worrying over.

Thats my conundrum. I don't just want mine fixed, but want to understand WHAT CHANGED so I can prevent it from happening again. I have studied the system closely and will list the possible causes at the end of this post.
Mine was like yours- perfectly fine with no marks for 7-8 years and many thousands of rounds fired. Then, all of a sudden, I have a rather deep gouge with no warning or explanation as to how or why. I will say that you should watch yours closely.



Plastic dummy loads do fine at protecting the breech, this happened BEFORE I started using them. I had dry fired it on an empty chamber many times at the end of a range session and after cleaning with no ill effects. I now know to protect it with dummy rounds, BUT I often let my friends and my kids shoot my guns. All of my .22s are safe to dry fire, except this one- and that's new. I can't be certain that others won't accidentally drop the hammer on an empty chamber, so I want it fixed in a way that puts it back to where it was, safe to dry fire without worrying about damaging it. I don't know if the inertia is enough, but I'm more inclined to think that it's a direct impact with the momentum and force of the hammer and mainspring involved.



Thanks for that, I'm still in the "diagnosis phase". While I agree that tuning the overall FP length is a potential fix, my FP length is not what changed, protrusion did.
I did NOT spill Viagra on my FP


And


Thanks for the link, I read a lot of that thread and plan to read the rest later. Most of the discussion was about guns that came peened from the factory, and my situation is different as SOMETHING about my pistol changed to make this condition possible.

WHAT COULD CAUSE FP Protrusion to INCREASE in a 2001+ Buck Mark?

My thoughts:

What stops the FP on an EMPTY CHAMBER?

-The FP stop pin
-full detent of the FP into the rear of the bolt allowing the hammer to strike the bolt
-contact with the breech

So, what could CHANGE a gun to allow PEENING?

1) The FP stop hole in the FP itself has been beaten and worn from hammer strikes on an empty chamber, where the stop pin is contacting the FP. (I will need to measure my FP and compare to a new one)

2) The FP stop pin itself is deformed (not the case)

3) The hole in the plastic housing for the FP stop has been hogged/stretched out to allow further protrusion (not the case, pin fits tight)

4) The plastic housing itself has become compressed and allowed protrusion to increase.


My suspicion is that condition (1) or (4) is to blame...either the stop pin hole in the FP itself has elongated from abuse, taking hammer strikes without a brass rim to cushion the blow and stop the FP, or the plastic housing has deformed from taking a beating.

I will likely know much more when I get the new assemblies and can compare my old, worn parts to new ones.

I sincerely appreciate all the time and effort that you all put into answering this question.

I really do hope I get a solid answer to what I believe is the most salient question here...What Changed?

Respectfully,

DrGunner
I think the inertia could mark the breech face. But I just have a hard time believing such a small, lightweight piece of steel could make such a deep impression in the breech face by only its own inertia. But I could be wrong!

I suppose it's not really much of a problem. But what I've found (and the photos to demonstrate my measurements on my Buck Mark are in that other long thread) is that with the bolt closed, with a fired casing in the chamber, when the tip of the firing pin is pressed into the dent in a fired casing's rim, the back of the firing pin still protrudes out the back of the bolt such that the hammer cannot contact the bolt.


I had to hold the gun together to get the firing pin into the dent in the already fired casing.


But you can see that the back of the firing pin holds the hammer away from the back of the bolt on my gun.

The combination of the compressed cartridge casing rim and the firing pin's length is enough to prevent the hammer from striking the back of the bolt in my Buck Mark. And I like that.

That gives me two good pieces of information.

First: All of the energy stored in the hammer's momentum is transferred to the case rim. None of it is wasted smacking the back of the bolt when actually firing the gun. That's great, IMO. It makes for very positive ignition.

Second: The hammer will not strike the back of the bolt when firing normally. It'll only happen when dry firing.

It may not be anything to worry about, but all of that information is relevant when deciding how long the firing pin in this gun should be (and possibly relevant to troubleshooting what's happened with yours).

I agree with that entirely! We need to fully understand what has happened with your gun in order to fix it and prevent it from happening in the future. It really is a nice mystery!

You state: "
I'm more inclined to think that it's a direct impact with the momentum and force of the hammer and mainspring involved."

And I agree completely with that, too. I just have a hard time imagining that the inertia of the firing pin would be capable of making a dent that deep unless it happened hundreds or thousands of times.

Here are some thoughts:

First, we believe that the firing pin didn't get longer.

Second, we suspect that the inertia of the firing pin alone isn't likely to be able to do that much damage.

That leaves us with the idea that somehow, the inertia of the hammer itself must have come into play.

In order for that to happen, either the firing pin must have gotten longer OR the length of the bolt has gotten shorter, or the face of the hammer has changed shape a bit to let it push the back of the FP in beyond the back face of the bolt.

What if repeated blows from the hammer have pushed the back of the bolt in a bit, allowing it to push the FP further forward? And/or those same blows have reshaped the face of the hammer, allowing it to fit into the slot in the back of the bolt a bit, also allowing it to push the firing pin in a bit deeper?

I don't know how likely that is, but something has to have changed.

Of course, it could be that the inertia of the firing pin is greater than I imagine.

Before you get the new parts, you can do one of the tests I did on mine (back in that old thread), and see how far forward you can push the firing pin while it's all in the bolt.

I just took the bolt off of the gun, pressed the back of the FP in as far as I could with a small screwdriver or something (farther in than the back of the bolt) until the retention pin stopped it. Then I looked across the front of the bolt to see if I could make the tip of the FP protrude beyond the plane of the face of the bolt that contacts the breech face.

In my gun, I could not / cannot. The retaining pin stops it short of that plane. So it can't strike the breech face even by inertia.



I wonder if yours can, at this point? If it can, then maybe I'm underestimating the energy that is contained in the firing pin's inertia.


Then, you can also look at the back of the bolt and see how far the firing pin protrudes when you just press the back of the FP flush with the back of the bolt using some tool. I think I used a screwdriver for that.

And then you can also inspect the back of the bolt and the front of the hammer to see if there's some way the hammer could now be pushing the back of the FP in deeper than it used to.

A agree. The Viagra Firing Pin hypothesis seems far fetched!

I bought a new firing pin for my Buck Mark just because I wanted to see how its dimensions compared with those of my old one. While my old one is obviously worn, and polished, the dimensions are incredibly close.


Holding the two together to visually compare.













The actual measurements I made are somewhere in that other long thread. But they were, as I recall, as close as I could measure with my calipers.

I was mainly just curious to see if these firing pins were consistent in their dimensions, in case the cause of the peening in factory-new guns might be from overlength firing pins.

Of course, just checking one of them doesn't tell us too much. But I was amazed how close the old and new one of mine were.
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Old 02-23-2016, 10:31 PM
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Originally Posted by Patriotpappy View Post
DrGunner this will not solve your mystery but is related and would seem to be the solution to prevent breech peening from dryfire on most any rimfire. Some guns have a small recess machined into the breech face to coincide with where the firing pin would make contact with the breech. This prevents a slight excess firing pin protrusion from causing damage to the chamber. I happened to have my Martini handy, I looked and it has the recess. I suppose it is still possible for an inertia firing pin, without a firing pin stop to move forward far enough and with enough force to strike the bottom of the recess but that seems pretty unlikely. Any thoughts here why this feature is not used on most guns? If just a couple of accidental dryfires (as opposed to repetitive "dryfire practice") can cause this kind of damage I would think the recess would be standard operating procedure.
The only problem I could see from having a recess in the breech face right where the firing pin strikes is that it might give less compression and instantaneous impact to the priming compound because the case rim could deform into that recess rather than being really squeezed hard between the breech face and the tip of the firing pin.

Or maybe they're afraid that allowing the firing pin to push the case rim into a recess might be more likely to stress the brass in sort of a cutting or shearing fashion, leading to possible case ruptures right at that point.

I think it's something they'd have to design and test very carefully.

On most of my other .22s, there is some mechanism that stops the movement of the firing pin just short of being able to strike the breech face. The CZs, Rugers, etc., that I have cannot peen.

Yet it was always common wisdom, when I was growing up, to never dry-fire a .22. So clearly some designs must allow peening.

I looked at a brand new Buck Mark at a local gun store the other day. It's breech face was peened right out of the box. And I understand this is the way they come these days.
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Old 02-23-2016, 10:35 PM
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Quote:
Originally Posted by Baklash View Post
That seems to be a very deep peen for as little dry firing as you describe, so it's definitely not due to dry fire. I've used the yellow dry wall anchors, but don't always have one handy. I recently made a thin plastic tag that I keep on my key ring. It's maybe the thickness of a credit card, probably a little less. It fits right into place when I need it.
That's a clever idea, one that I will gladly take. The BM open breech design makes that one person easy to do. Why didn't I think of that?

That's what I love about discussion boards... Ideas freely shared
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Old 02-23-2016, 10:47 PM
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The only problem I could see from having a recess in the breech face right where the firing pin strikes is that it might give less compression and instantaneous impact to the priming compound because the case rim could deform into that recess rather than being really squeezed hard between the breech face and the tip of the firing pin.

Or maybe they're afraid that allowing the firing pin to push the case rim into a recess might be more likely to stress the brass in sort of a cutting or shearing fashion, leading to possible case ruptures right at that point.

I think it's something they'd have to design and test very carefully.

On most of my other .22s, there is some mechanism that stops the movement of the firing pin just short of being able to strike the breech face. The CZs, Rugers, etc., that I have cannot peen.

Yet it was always common wisdom, when I was growing up, to never dry-fire a .22. So clearly some designs must allow peening.

I looked at a brand new Buck Mark at a local gun store the other day. It's breech face was peened right out of the box. And I understand this is the way they come these days.
Jim, could you please elaborate a bit more on which Ruger's you refer to? I'm not trying to shake anybodies tree here, but I have bukoo evidence that shows the Ruger Mark pistols, under the right conditions, having factory installed firing pin stop pins, that have chamber mouth dings. Photos, of pistols that have crossed my bench with the firing pin divot.
Back in the day, I was also schooled by WWII Veterans who told me that if I were to EVER dry fire a .22 rimfire in their presence, I would never be able to get involved with creating children.
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Old 02-23-2016, 11:01 PM
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Originally Posted by Jim_WY View Post








First, we believe that the firing pin didn't get longer.

Second, we suspect that the inertia of the firing pin alone isn't likely to be able to do that much damage.

That leaves us with the idea that somehow, the inertia of the hammer itself must have come into play.

In order for that to happen, either the firing pin must have gotten longer OR the length of the bolt has gotten shorter, or the face of the hammer has changed shape a bit to let it push the back of the FP in beyond the back face of the bolt.

What if repeated blows from the hammer have pushed the back of the bolt in a bit, allowing it to push the FP further forward? And/or those same blows have reshaped the face of the hammer, allowing it to fit into the slot in the back of the bolt a bit, also allowing it to push the firing pin in a bit deeper?

I don't know how likely that is, but something has to have changed.

Of course, it could be that the inertia of the firing pin is greater than I imagine.

Before you get the new parts, you can do one of the tests I did on mine (back in that old thread), and see how far forward you can push the firing pin while it's all in the bolt.

I just took the bolt off of the gun, pressed the back of the FP in as far as I could with a small screwdriver or something (farther in than the back of the bolt) until the retention pin stopped it. Then I looked across the front of the bolt to see if I could make the tip of the FP protrude beyond the plane of the face of the bolt that contacts the breech face.

In my gun, I could not / cannot. The retaining pin stops it short of that plane. So it can't strike the breech face even by inertia.



I wonder if yours can, at this point? If it can, then maybe I'm underestimating the energy that is contained in the firing pin's inertia.


Then, you can also look at the back of the bolt and see how far the firing pin protrudes when you just press the back of the FP flush with the back of the bolt using some tool. I think I used a screwdriver for that.

And then you can also inspect the back of the bolt and the front of the hammer to see if there's some way the hammer could now be pushing the back of the FP in deeper than it used to.

A agree. The Viagra Firing Pin hypothesis seems far fetched!

I bought a new firing pin for my Buck Mark just because I wanted to see how its dimensions compared with those of my old one. While my old one is obviously worn, and polished, the dimensions are incredibly close.

The actual measurements I made are somewhere in that other long thread. But they were, as I recall, as close as I could measure with my calipers.

I was mainly just curious to see if these firing pins were consistent in their dimensions, in case the cause of the peening in factory-new guns might be from overlength firing pins.

Of course, just checking one of them doesn't tell us too much. But I was amazed how close the old and new one of mine were.
Jim- I'd like to open with a thanks for your time and effort here. You've always been a very helpful and civil contributor here in the Browning forum, CZ and elsewhere.


I have inspected mine some, but need to check some things closer.

First off, pushing my FP from the back, the rear of mine sinks deeper into the bolt than yours, BUT NOT QUITE FLUSH- it still protrudes. There are no hammer marks on the back of my bolt.

Second, pushing my FP from the back, it does protrude past the bolt face ever so slightly... When I say that, I mean I push with a punch as hard as I can with the bolt locked in a padded vise and the tip of the FP protrudes by such a slight amount, it's on the order of .00X. Still- ANY past the bolt face is a BAD THING

Third- I highlighted some of your comments in red because I think we are not quite on the same page as to what STOPS the forward motion of the FP...
You made the inference "In order for that to happen, either the firing pin must have gotten longer OR the length of the bolt has gotten shorter, or the face of the hammer has changed shape a bit to let it push the back of the FP in beyond the back face of the bolt."

On an EMPTY CHAMBER, what limits the forward protrusion of the FP?

I thought it was the cross pin that goes through the center hole.

We can agree-

1) The FP hasn't gotten longer

2) The bolt hasn't gotten shorter (although in my mind, the jury is still out on the plastic housing)

3) My hammer face hasn't changed shape.

So, I really do think that either the retaining pin hole in the FP gave up something, or the plastic housing did, or perhaps a combination of both.

The breech face is hard barrel steel, so I've all but discounted the inertia theory.

I really don't think I will have solid answers until I have the new parts to compare.

When I do, I PROMISE I will disassemble my old parts and the two new assemblies and measure all. I will also do all of the same tests you described to see if there's anything to be learned there...

Thanks again!

DrGunner
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Old 02-23-2016, 11:18 PM
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DrGunner this will not solve your mystery but is related and would seem to be the solution to prevent breech peening from dryfire on most any rimfire. Some guns have a small recess machined into the breech face to coincide with where the firing pin would make contact with the breech. This prevents a slight excess firing pin protrusion from causing damage to the chamber. I happened to have my Martini handy, I looked and it has the recess. I suppose it is still possible for an inertia firing pin, without a firing pin stop to move forward far enough and with enough force to strike the bottom of the recess but that seems pretty unlikely. Any thoughts here why this feature is not used on most guns? If just a couple of accidental dryfires (as opposed to repetitive "dryfire practice") can cause this kind of damage I would think the recess would be standard operating procedure.
I don't have any guns with the recess you refer to, but it certainly sounds like a logical precaution. Any way you can post a pic? If you don't have photo hosting, send me an email with the pic(s) and I will host them on my Photobucket account.

Thanks for weighing in

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Old 02-24-2016, 12:09 AM
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Originally Posted by SGW Gunsmith View Post
Jim, could you please elaborate a bit more on which Ruger's you refer to? I'm not trying to shake anybodies tree here, but I have bukoo evidence that shows the Ruger Mark pistols, under the right conditions, having factory installed firing pin stop pins, that have chamber mouth dings. Photos, of pistols that have crossed my bench with the firing pin divot.
Back in the day, I was also schooled by WWII Veterans who told me that if I were to EVER dry fire a .22 rimfire in their presence, I would never be able to get involved with creating children.
I wasn't thinking of the Ruger pistols, actually. And you may have a very valid point! I have one, that I got used from a friend, but I haven't played with it much. So I suspect you're correct.

I was thinking of the 10-22 rifle and the CZ .22 Rifles I have.

And I guess what you were taught and what I was taught when we were younger was the same. Don't ever dry-fire a .22.

But aren't there some of the shooting sports where you need to be able to dry fire the gun at the end of your shooting to meet the rules? If so, then people must have a way to do it safely.

I just got one of those new SW22 Victorys. And the mechanism that keeps you from releasing the hammer if the bolt is out of battery is very strict! There's no way it would release if you had a credit card's thickness between the bolt and breech. Even half or less of that gap, and it won't go.

My Buck Mark is much more forgiving. That's good and bad, I suppose. It's more able to have an out of battery ignition, but it lets us decock it much more easily without allowing it to peen.

Quote:
Originally Posted by DrGunner View Post
Jim- I'd like to open with a thanks for your time and effort here. You've always been a very helpful and civil contributor here in the Browning forum, CZ and elsewhere.

Thank you. That means a lot to me coming from you.

I have inspected mine some, but need to check some things closer.

First off, pushing my FP from the back, the rear of mine sinks deeper into the bolt than yours, BUT NOT QUITE FLUSH- it still protrudes. There are no hammer marks on the back of my bolt.

Keep in mind, the test I was performing was to let the hammer push the firing pin forward while what I considered to be a good representative fired casing was in the chamber, with the firing pin indentation lined up with the firing pin's nose so that what we're seeing is how far the back of my firing pin protrudes while a fired round's pinched rim is holding the firing pin's nose back away from the breech.

It's a pain to do that test. Especially to then hold the whole mess while taking a picture of it with the other hand!

I think that's what you were doing, too, but I just want to make sure. And I always imagine that the depth of the dent in any given casing will depend on the original rim thickness, the brass alloy used, how hard it was, etc., so different fired cases may well exhibit a range of thicknesses measured in the dented area.


Second, pushing my FP from the back, it does protrude past the bolt face ever so slightly... When I say that, I mean I push with a punch as hard as I can with the bolt locked in a padded vise and the tip of the FP protrudes by such a slight amount, it's on the order of .00X. Still- ANY past the bolt face is a BAD THING

I still don't really have a good feel for how much inertial energy the firing pin will have during a dry-fire. It may be that you can press the firing pin forward farther than it would actually travel under only its own inertia, but I agree that any protrusion is more than I'd like to see.

But, I will say that I didn't push forward on mine as hard as you probably did. I pushed it firmly, but not as hard as I could have with the bolt in a vice and a tool pressed very hard against the back of the FP.

The plastic block might have a bit of give that would have allowed me to push it a bit further, but I felt like I pushed it as hard as the firing pin's inertia could. But then again, who's to say?


Third- I highlighted some of your comments in red because I think we are not quite on the same page as to what STOPS the forward motion of the FP...
You made the inference "In order for that to happen, either the firing pin must have gotten longer OR the length of the bolt has gotten shorter, or the face of the hammer has changed shape a bit to let it push the back of the FP in beyond the back face of the bolt."

On an EMPTY CHAMBER, what limits the forward protrusion of the FP?

I thought it was the cross pin that goes through the center hole.

I agree completely with that. On an empty chamber, the only thing stopping the forward movement of the firing pin is the cross pin and the center hole in the FP itself.

So what I was talking about was what could happen to allow the hammer's force and energy to be imparted, via the FP, to the breech face. This, because I still have a hard time imagining that just the inertia of the FP has done this damage.


If the firing pin block has gotten shorter, or the hole in the block for the cross pin has gotten wallered out, or the hole in the firing pin itself has elongated - anything that is letting the firing pin move forward farther than it did before, then, when dry firing, it could fly forward and strike the breech face with its own inertia.

But to allow the hammer's energy to be transferred through the FP to the breech face, the firing pin would have to grow, or the hammer's face change shape a bit, or the back of the bolt get pounded in a bit, or something else that would alter the distance between the back of the bolt and the breech face.

I could imagine someone machining down the bolt's frontmost face to get a smaller headspace, and that would shorten that distance.


But perhaps I'm not giving the firing pin's inertia enough credit! Maybe that little thing really takes off fast when struck by the hammer during a dry fire, and the velocity is high enough to do some damage!

It's just that the peen mark looks so deep on yours that I wouldn't have imagined it was caused without the direct action of the hammer.


We can agree-

1) The FP hasn't gotten longer

2) The bolt hasn't gotten shorter (although in my mind, the jury is still out on the plastic housing)

3) My hammer face hasn't changed shape.

So, I really do think that either the retaining pin hole in the FP gave up something, or the plastic housing did, or perhaps a combination of both.

I agree with that. But that does only allow for firing pin inertia as the source of all of the damage. Again, perhaps I'm not giving that inertia nearly enough credit!

The breech face is hard barrel steel, so I've all but discounted the inertia theory.

I really did, too. But without the firing pin growing or the distance between the back of the slide and the breech face getting shorter, how could that happen?

I really don't think I will have solid answers until I have the new parts to compare.

When I do, I PROMISE I will disassemble my old parts and the two new assemblies and measure all. I will also do all of the same tests you described to see if there's anything to be learned there...

Thanks again!

No problem. This is very interesting! Troubleshooting is what I've done for most of my life. It's a good job and good fun, too! I appreciate the challenge you are presenting.

DrGunner
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Old 02-24-2016, 12:35 AM
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I just had an idea.

Is this the gun in which you've installed the VQ hammer? If so, did the peening begin about that time?

I'm wondering if the face of the new hammer might not be shaped a bit differently such that it engages the back of the firing pin a bit differently, and can now push the firing pin forward a bit farther than the factory hammer was able to do.

If so, then what I'd do is just stone the firing pin down a bit to shorten it such that the new hammer cannot drive it past the front of the bolt face.

I'm not sure which end of the FP I'd stone down, but maybe it'd make the most sense to do both ends a bit.

I'd shorten the back to make it work more like how it worked with the old hammer so the hammer cannot drive it forward such that the retaining pin (cross pin) is being hit with the full force of the hammer. I envision it as only being designed to catch the firing pin's own inertia, not that of the hammer.

Then I might take a bit off of the nose of the FP, too, if it can now stick out past the front plane of the bolt when pressed inwards past the back of the bolt.

But it sounds like you were pressing pretty hard on it when you did that test. So I'm not even sure that would be required.

Also, if the new hammer has been applying its force through the FP to the retaining pin and the plastic housing, maybe the housing has been compressed a bit from that.

As inexpensive as all of these pieces are, it might make sense to replace the little plastic housing, the cross pin, and the FP, and then measure all of that and shorten the FP a bit (at the back, particularly) if necessary.

When troubleshooting anything, I don't like unsolved mysteries. I really love it when the culprit can be found out, proven, and then dealt with!
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Old 02-24-2016, 12:52 AM
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Jim,

There was a spate of time when Ruger was substituting a "roll-pin" used for the firing pin stop pin instead of the solid, heat-treated pin. Unbeknownst to the owners of those pistols, rather than a solid firing pin stop pin. They indeed did use a solid, heat treated stop pin since the inception of the Ruger Standard back in 1949. The substituted firing pin stop pin, or roll pin, has a slot in that pin. If that pin was positioned with the slot at either 12:00 o'clock or 6:00 o'clock, the pin would collapse from the forceful hits of the hammer onto the hardened firing pin, causing this condition:



The roll-pin was shorter on each end, totaling an eighth of an inch, which made it easier for the force from the mainspring to collapse that roll-pin and have the firing pin reach further forward and then create the ding we see above.



Now, what's going on with the Buckmark and why the breach face is getting smacked by the firing pin is more than annoying and needs to be investigated. Is the firing pin REALLY too long? Is the oblong hole in the firing pin itself overly long, and does it allow the firing pin to travel that much further forward to cause concern? Is the firing pin stop pin too soft and being deformed from the hammer hits to allow more forward travel than necessary? Inquiring minds would certainly like to know.
I have ordered all the parts involved with how the firing pin, polymer block, firing pin stop pin and whatever else is involved, because, "I gots to know" what the heck is going on here. If the solution requires my machining an aluminum block to hold the firing pin parts, I'll do that. Until I reach a discernable conclusion as to what I can be satisfied with for a fix, I'll continue to use the yellow wall anchors that I've been using for snap-caps since 1986 to prevent that gut-wrenching, friggen, chamber ding that makes me want to puke.
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Old 02-24-2016, 07:19 AM
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Originally Posted by Jim_WY View Post
I just had an idea.

Is this the gun in which you've installed the VQ hammer? If so, did the peening begin about that time?

I'm wondering if the face of the new hammer might not be shaped a bit differently such that it engages the back of the firing pin a bit differently, and can now push the firing pin forward a bit farther than the factory hammer was able to do.

If so, then what I'd do is just stone the firing pin down a bit to shorten it such that the new hammer cannot drive it past the front of the bolt face.

I'm not sure which end of the FP I'd stone down, but maybe it'd make the most sense to do both ends a bit.

I'd shorten the back to make it work more like how it worked with the old hammer so the hammer cannot drive it forward such that the retaining pin (cross pin) is being hit with the full force of the hammer. I envision it as only being designed to catch the firing pin's own inertia, not that of the hammer.

Then I might take a bit off of the nose of the FP, too, if it can now stick out past the front plane of the bolt when pressed inwards past the back of the bolt.

But it sounds like you were pressing pretty hard on it when you did that test. So I'm not even sure that would be required.

Also, if the new hammer has been applying its force through the FP to the retaining pin and the plastic housing, maybe the housing has been compressed a bit from that.

As inexpensive as all of these pieces are, it might make sense to replace the little plastic housing, the cross pin, and the FP, and then measure all of that and shorten the FP a bit (at the back, particularly) if necessary.

When troubleshooting anything, I don't like unsolved mysteries. I really love it when the culprit can be found out, proven, and then dealt with!
Hey Jim- the peen first appeared last fall, the VQ hammer went in last week, so that's not the culprit.

The low price tag ($6) makes me suspicious that there's a problem there and the entire kit and kaboodle are often replaced.
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Old 02-24-2016, 07:21 AM
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You can get the full FP assembly for $6.00 and change from Browning parts department. The source you mentioned is almost always 2x or more for same parts.

Also check out this tool if damage is more severe.
http://www.brownells.com/gunsmith-to...-prod8869.aspx
Do you have a link to where the entire assembly lists for $6 from Browning?

Thanks-

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