New Breech Block Mod....I can hear Walther groan - RimfireCentral.com Forums

Go Back   RimfireCentral.com Forums > >

Join Team RFC to remove these ads.
Reply
 
Thread Tools Display Modes
  #1  
Old 08-15-2010, 09:06 PM
1917-1911M
US Army Veteran

Join Date: 
Feb 2005
Location: 
Indian Springs, AL
Posts: 
8,435
TPC Rating: 
0% (0)
New Breech Block Mod....I can hear Walther groan



Log in to see fewer ads
So I got to thinking as I was playing around with a P22......hammer hanging in the breech block gap?????? Safety bar cocks the hammer and then the hammer drags along the bottom of the breech block all the way rearward and all the way forward....unless you do the breech block mod. Still, the hammer has to jump over the safety bar, AND, the hammer still needs to ride up on top of the breech block before it gets to the firing pin block..... Which set me to thinking....why does the safety have to cock the hammer????? Why does the rear of the breech have to cock the hammer??? Why not file off the bottom of the safety bar when it is set to the fire position so that it no longer cocks the hammer or even touches it. In fact why not file off the rear of the breech block so it no longer ramps up to the safety bar and in the process no longer touches the hammer either.

Why not leave cocking of the hammer to the bottom of the breech block, say.....at the area where the roll pin is inserted. Let the hammer ramp up it, be pressed down enough to be cocked, the slide bounce off the takedown lever stop, slide back down the breech block forward to chamber a round. This would cause the only friction area to be overcome when the recoil spring was fully compressed and the rear of the breech and the safety would no longer ever touch the hammer. No more rotating safety, no more hammer tip hanging or bumping over the safety.........

Now things aren't necessarily that simple. We've previously determined that the hammer rebounds appx 0.020" and removing material from under the breech frees it from drag on the hammer....but removing material from the safety bar is another issue altogether. It is the safety after all and a number of safeties on the PK380 have broken. Why????? I don't know, other than too weak. I've never read of a safety breaking on the P22 although the two pistols share the same hammer and hammer spring. The PK380 does have a different firing pin.

Removing material will make the safety weaker for those who drop the hammer on it when dry firing. I don't so I'm not concerned about that. Also, is it possible to remove, say....0.025"/0.030" from the bottom of the bar and have enough material left to block the hammer when the safety is set to safe. Yes, there is enough material. So I took an old breech block, an old safety bar, and old file from the "Make your own extractor from the barrel wrench" thread and had at it. So far so good. This is just an experimental procedure at this point. I have pictures of the process which I will add tomorrow and which is why I didn't finish the sight options.

The weekend is just too short. I'm voting for a 5 day weekend and a 2 day workweek.....who is with me???? M1911


Here is the idea....remove 0.025"/0.030" from a stock breech block and safety bar....area marked in red. The idea is that the hammer would no longer drag on these areas at all.

Here I've set the safety levers to the fire position....the only position I'm concerned with.... and I'm filing off 0.030" of material from the very bottom of the safety bar. I am not removing material from where the hammer is blocked by the safety when rotated to the safe position.


Below is the finished prototype...no need to polish... nothing touches the filed areas. The hammer isn't touching the breech block or the safety bar. Talk about a free slide....yet I've never cracked one. I will get up a photo-shopped picture to show the process. And I need to whack that safety 500 times to see if I can break it due to the removal of material....so don't anyone light into this assuming this is a proven mod. I'm just playing... thing might blow up....



Here material has been removed so the hammer no longer drags on the bottom of the breech block as the slide moves forward. Rearward movement was never an issue except with too weak ammo. Forward movement of the slide was where the issue was. Here the safety drum presses the hammer back appx 80% of what is needed for cocking while the bottom of the breech block finishes the job. Once cocked, the slide is free to move forward.

Last edited by 1917-1911M; 06-27-2018 at 05:37 PM.
Reply With Quote
  #2  
Old 08-16-2010, 02:55 AM
Glenn-SC

Join Date: 
Aug 2004
Posts: 
926
TPC Rating: 
0% (0)
I can hear the Lawyers filling out papers now .....
Reply With Quote
  #3  
Old 08-16-2010, 08:52 AM
1917-1911M
US Army Veteran

Join Date: 
Feb 2005
Location: 
Indian Springs, AL
Posts: 
8,435
TPC Rating: 
0% (0)
Here is a picture of the broken safety that some PK 380s are experiencing. There doesn't seem to be as much metal inside this safety possibly due to the size and location of the firing pin. There have been no accidental discharges due to this to date from what I can read but since the PK380 shares the same hammer and hammer spring with the P22 it sure seems like dry firing either and depending on the safety to stop the hammer might be a bad idea. The mod above will weaken the structural integrity of the P22 safety...will it cause it to crack...don't know. Will the safety still work if it doesn't break....absolutely. No safety features are being deleted. M1911


http://img44.imageshack.us/img44/408/1002221c.jpg
Reply With Quote
 
  #4  
Old 08-16-2010, 12:02 PM
Bob Steele
NRA Member - Click Here To Join!

Join Date: 
Mar 2009
Location: 
unfortunately now in Maryland land of gun control
Posts: 
61
TPC Rating: 
0% (0)
Hi 1911M,

Maybe I'm not quite understanding all of what you said, because it seems to me the hammer will still drag on the bottom of the safety, then the filed down breech block, until it is fully cocked by the unreleaved area above where the roll pin is, each time the slide assy is either pulled back to cock the hammer before shooting the first shot, and every time the slide recoils from a shot to again cock the hammer and seat the next round.

I DO like the concept as the problem with mine is it seems to be "stalling" on its trip back after being cocked, and this mod probably would eliminate contact during that direction of travel.

Maybe I need to "profile" the hammer a bit more as mine still touches the breach block even in the areas I have releived it. I do not have quite as precision equipment as some, but a new caliper will make it much easier to see exactly how much I have relieved it next time I take it appart

I have worked the mod on the breech at least 2 times trying for a longer sloping ramp from the relieved area to the safety pin, but it still seems to "hang" in the slight space between the breech and the safety pin.

Keep us posted though, as this seems to make lots of sense.

Bob
Reply With Quote
  #5  
Old 08-16-2010, 02:01 PM
1917-1911M
US Army Veteran

Join Date: 
Feb 2005
Location: 
Indian Springs, AL
Posts: 
8,435
TPC Rating: 
0% (0)
Good points Bob......man, you must have a mind like a Steele trap. You are right the safety will be the first item to hit the hammer but higher up which will be an improvement ( I think) havent' tested any of this yet.... There is a slightly redesigned firing pin retainer for 1911s that makes a huge difference in the amount of pressure and smoothness encountered when cycling the slide. You would not think such a small change would have that amount of impact. That is what I'm trying to do here.

The safety will hit the hammer higher....better leverage and the un-relieved portion of the breech will complete the cocking of the hammer. The recoil spring will be fully compressed or at it's highest push point for moving the slide forward. After that the cocked hammer will no longer even touch the rear of the breech or the safety which is where the problem occurs of the hammer catching.

I also want to whack on the safety hundreds of times and fire the pistol a quick 500 times to see if stuff holds up. Just another mod but on I think might improve things and will eliminate removing material from the breech in the vicinity where the retaining pin sits and keep people from removing material adjacent to the firing pin block. In other words....a simpler and stronger mod....if the safety can handle it. More later with some pictures..... M1911
Reply With Quote
  #6  
Old 08-16-2010, 09:54 PM
1917-1911M
US Army Veteran

Join Date: 
Feb 2005
Location: 
Indian Springs, AL
Posts: 
8,435
TPC Rating: 
0% (0)
Put the pistol back together and there was enough metal left under the original breech mod so that the hammer still cocks when hand cycling. After the hammer is cocked and the slide moves forward about 1/4" there is no drag at all on the hammer. The hammer doesn't cock until the slide has moved all but the last 1/4".

I whacked the safety about 300 times set to safe and 200 set to fire. No damage to anything.

It might be my imagination but I think the safety hitting 0.030" higher up the hammer makes pressing the hammer rearward easier. I might be able to test that with a trigger pull gauge if I can determine that the trigger spring pressure between two pistols requires the same pull to cock the hammer. A new pistol requires 8 lbs of pull on hammer to cock it.

The problem with the safety bar and the gap between it and the breech where the hammer tip could catch was never on the rearward movement of the slide. It was on the rebound when the nose of the breech had to shove a round out of the magazine while the rear of the breech and safety was still dragging over the hammer. This cures that but I still haven't fired it. Will do that tomorrow and report back.

I think I will modify one of the new breech blocks I have and fit it to the pistol and see how that works if everything works out when firing tomorrow. At this point about the only thing slowing the slide down is the recoil spring. M1911
Reply With Quote
  #7  
Old 08-16-2010, 10:32 PM
one_slayer

Join Date: 
Aug 2007
Posts: 
6
TPC Rating: 
0% (0)
Wow, I am amazed at you work.
Reply With Quote
  #8  
Old 08-16-2010, 10:46 PM
1917-1911M
US Army Veteran

Join Date: 
Feb 2005
Location: 
Indian Springs, AL
Posts: 
8,435
TPC Rating: 
0% (0)
Me too......wish I had some sort of machine shop instead of just some old files, a hammer and sandpaper....I could really have some fun. The slide above isn't even fitted on the pistol it came off of but the picture illustrates where I'm going with this....I think. M1911



What the original breech block mod looked like...

Last edited by 1917-1911M; 08-17-2010 at 12:01 AM.
Reply With Quote
  #9  
Old 08-17-2010, 07:05 AM
Bob Steele
NRA Member - Click Here To Join!

Join Date: 
Mar 2009
Location: 
unfortunately now in Maryland land of gun control
Posts: 
61
TPC Rating: 
0% (0)
I think I will order a new breech block, hammer, and safety pin - just in case - and get on tryng this new mod, as I am right now having problems with the hang up when the tip of the hammer drags back over the safety pin / breech area.

From the pic above, I made a gradual sloping ramp all the way from the cut out just behind the roll pin area up to the junction with the safety pin. the first mod looked very much like the picture above, and it seemed to catch on the lip as shown and stop in the small open area between the breech and safety pin. A slight touch with the thumb sent it home, but that is not what I want obviously.

Bob
Reply With Quote
  #10  
Old 08-17-2010, 09:18 AM
1917-1911M
US Army Veteran

Join Date: 
Feb 2005
Location: 
Indian Springs, AL
Posts: 
8,435
TPC Rating: 
0% (0)
Bob, S&W sent me a half dozen breech blocks to fool around with. One is for drilling and tapping to mount a small red dot. Did a thread on that. The breech mod above does in fact need the rear ramp to be smoothed up and it was....just not for this picture. There was too much of a sharp ramp there. Later I removed the firing pin block and removed enough material on one breech block so that the hammer never encountered the breech once if slide over the safety bar and rear ramp. But of concern to me was always the removal of material below the area where the roll pin set.

Now I never experienced any problem there but the breech block was surely weakened at that point. It is 0.040" thick stock and I was reducing this thickness by 0.020"/0.025". That left only 0.015" of steel to hold the device in place. Again, I never saw any problems. What I am proposing now is to only have one ramp and to ramp up over the location of the roll pin. This would insure plenty of strength remains there and would not cause any work to be performed near the firing pin block.

What would happen is everything from the roll pin rearward would be lowered 0.025"/0.030" so that the cocked hammer no longer even touches the breech block/safety as the slide moves forward. You must leave the edge of the safety that blocks the hammer untouched. So far I've been unable to damage the safety even with the metal removed as pictured. I really whacked it last night about 500 times dry firing safety on and in the fire position and there were no marks at all and no broken safety. I think the P22 safety has much more metal in it than the PK380.

It might be possible that this mod eliminates re-profiling the hammer altogether. Wish I had a machine shop that could make precise cuts...but a file does a pretty good job. Dremels run too fast and are hard to hold steady. I'd buy a variable speed one next time. All I can say is that so far my slide without the recoil spring in it flops back and forth. No more safety touching the hammer at all. The gap could be 1/4" wide and it wouldn't matter......the hammer doesn't touch it. Picture later. Busy today getting a plan ready. Need some work around here. Things have been very slow for two years. M1911



The original idea.



Then there was the tiny tapered roller bearing in the end of the hammer......



Then a picture with more explanation.....and one early P22 I had suffered from the safety bar hanging down below the breech block. Never have seen one like it since. Hence the removal of material from the safety in this drawing to make the bar flush wih the bottom of the breech block. This later prooved unnecessary. But now removal of material here is exactly what I'm proposing but not carrying the relief of metal under the breech as far forward. I've got to send this picture to Castor after I autograph it. For some wierd reason he wanted it. Haven't heard from him lately.....must have fallen in the lake his house overlooked.



Then I learned how to Photoshop a bit..... The thickness of the hammer...face to rear needs to remain 0.52" thick or the slide will not press the hammer down enough to cock it. If you are reprofliling the hammer face as shown above....stop there. 0.051" and the slide will not cock the hammer. Of course you need a caliper to measure this closely.

M1911

Last edited by 1917-1911M; 08-17-2010 at 09:48 PM.
Reply With Quote
  #11  
Old 08-17-2010, 05:35 PM
1917-1911M
US Army Veteran

Join Date: 
Feb 2005
Location: 
Indian Springs, AL
Posts: 
8,435
TPC Rating: 
0% (0)
50 RGB and Fed mix went well except for one dud Fed. 10 lb 8 oz avg of 5 to pull the modded slide rearward to cock hammer. 11lb 2 oz avg of five pulls on another smooth shooter with the old breech mod. 1/4 lb difference. Too close to call on whether or not moving the contact point up 0.030" makes any difference. Don't know if the springs match anyway.

I intend to wash all lube off the pistol and fire it entirely dry, not even any moly and see if it works fine with the new mod. So far nothing has broken and the pistol performed 100%. Gotta go. M1911
Reply With Quote
  #12  
Old 08-17-2010, 05:41 PM
Bob Steele
NRA Member - Click Here To Join!

Join Date: 
Mar 2009
Location: 
unfortunately now in Maryland land of gun control
Posts: 
61
TPC Rating: 
0% (0)
M1911

Just to be sure that I am reading things correctly I used the pic from above and edited it to make sure I am reading what you are saying. I think this is what you are suggesting:

http://springboro-massage.com/images/breech_mod.jpg

I carefully removed the safety from my gun and cycled it by hand to see where the hammer actually would "catch" and found it was just as expected.

I also realized that I had relieved the block all the way across the pin and not just up to it.

Never no mind, I have not seen any sign of breakage or anything from doing so.

I also ordered a spare breech, safety pin, and hammer assy from S&W (for $50.50) just in case anything I do in experiment form is too much.

Wish me luck.

Bob
Reply With Quote
  #13  
Old 08-17-2010, 08:37 PM
1917-1911M
US Army Veteran

Join Date: 
Feb 2005
Location: 
Indian Springs, AL
Posts: 
8,435
TPC Rating: 
0% (0)
You are pretty close. Try this. I can draw better than photoshop but this should show the mod concept. Right now I'm thinking this is the mod I should have thought of originally. It eliminates the hammer from dragging at all on the rear of the breech block and safety and seems to work much better than the other mod and leaves the retaining pin area at full strength.

BTW Bob, I filed my safety while leaving it in the slide, holding the levers in the fire position. The breech block was filed out of the slide with a 1/8" drift inserted through the retaining pin hole. This holds it nicely for filing purposes. Of course wash everything very thoroughly and relube before reassembly. And as I think you've determined you only need to remove material from the safety the width of the hammer, not across the entire safety. I removed material until the hammer no longer touched.....probably closer to .030".....whatever it took.....will measure sometime. M1911






Last edited by 1917-1911M; 08-22-2010 at 11:32 PM.
Reply With Quote
  #14  
Old 08-17-2010, 11:26 PM
Papa_Smurf

Join Date: 
Oct 2008
Location: 
Papillion, NE
Posts: 
21
TPC Rating: 
0% (0)
I'm trying to remember, about the original breech block mod.

Wasn't the purpose of the original to prevent the hammer from pushing up on the breech block at the moment when the slide is all the way back... Thus preventing the slide being forced up when only a small section of rails is holding it level, and preventing the rails/slide from wearing down.

I do like the new idea as it cut's down on the friction during the time the slide is stripping and feeding the next round. I guess like everything, it is a compromise...but this appears to be the better option. I can't wait to see more pictures and range reports.
Reply With Quote
  #15  
Old 08-18-2010, 12:36 AM
1917-1911M
US Army Veteran

Join Date: 
Feb 2005
Location: 
Indian Springs, AL
Posts: 
8,435
TPC Rating: 
0% (0)
Quote:
Originally Posted by Papa_Smurf View Post
I'm trying to remember, about the original breech block mod.

Wasn't the purpose of the original to prevent the hammer from pushing up on the breech block at the moment when the slide is all the way back... Thus preventing the slide being forced up when only a small section of rails is holding it level, and preventing the rails/slide from wearing down.

I do like the new idea as it cut's down on the friction during the time the slide is stripping and feeding the next round. I guess like everything, it is a compromise...but this appears to be the better option. I can't wait to see more pictures and range reports.
You are 100% right Papa...I wouldn't say the purpose was to keep the hammer from lifting the slide when only 1/8" of bearing surface remained but it was a benefit. And, you are right....you can't have it both ways. In fact the hammer moves about 1/2 way onto the firing pin block so in order to really free the slide with the original mod when fully rearward you needed to remove the block and remove enough material along the entire length of the hammer's travel. Some of us did that.. But with the moly, wear was eliminated in the grooves and rails and hopefully it never returns. I am thinking that if the safety holds up this is a better mod for freeing the slide on its way forward.

Actually a pretty easy mod. M1911
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off




All times are GMT -5. The time now is 06:02 PM.

Privacy Policy

DMCA Notice

Powered by vBulletin
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Search Engine Optimisation provided by DragonByte SEO (Lite) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright 2000-2018 RimfireCentral.com
x