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Stoning the Hammer

267K views 279 replies 112 participants last post by  Toomany22s 
#1 · (Edited)
To improve feel and lighten your trigger pull, grinding/Stoning the the angle on the area of engagement of the hammer is one way to achieve a smoother - crisper trigger. Best of all it can be done yourself for free (if you already have the tools). The tools you will need are stones, vise and a 1/8" drill bit.

In short: Slide the .125" drill bit through the pivot hole of the hammer then set the hammer in a vise so that the drill rod is sitting on both of the vise jaws. When tightening the vise set the bottom of the sear notch in the hammer level with the top of the jaws. Then remove any material of the engagement area that rises above the the vise by stoning or grinding.

This is how the setup should look:


In this pic note that the bottom of the notch is at the top of the vise jaw (red line) to help achieve this you can insert a razor blade in the notch and push down if the notch is too high.


cletus hungwell said:
I do my rough work w/ either a cheap, super course stone, or just use metal cutting sanding belts (i have plenty of those).... when i get down close, i bring it in to final size w/ a medium india, the buff w/ the paper wheel and compound.....

the paper wheel is the slotted paper buffing wheel sold/used by those knife sharpeners at the gunshows...... great product!!!.....firmer than hardest felt, cheap.....you can get them from texas knifemakers supply, jantz supply, or any of the knifemaker's supply houses........ it comes as a "kit" w/ 2 wheels, one is fine gritted, and w/ lube to cut heat, the other is the buff...it comes w/ le homiedou cr51 rouge....good stuff for alot of gun work......will put the "slick and shiny" on most any metal part, if you've got the skills.....

if you don't want to buy the paper wheel setup, just go up through the fine white arkansas stones...it will be fine for your finish!....
Here are some before and after pics, the difference is not very much.



How it works...
cletus hungwell said:
Changing the angle will reduce pull force required..... the extreme negative angle required to keep the hammer from slipping off the sear when it's dancin on it's pin during cycling is what makes the pull so heavy on the stock guns.......if you take a group out of a gun, you can watch the hammer being cammed to the rear as you pull the trigger...... what changing the angle does is reduce the amount of trigger pull force used to cam the hammer backwards against it's spring......the tighter the fit of hammer/sear to their pins, the less negative angle required......

of course, the combination of the two is what you'd go for when you're lookin for precision over reliability.... it's a balancing act, determined by your intended purpose of the group......

cletus
Why it works...
cletus hungwell said:
the angle is determined by a straight line running from the center of the pivot hole to the BASE of the sear notch....that line is 0deg.....

as most pivot holes i've checked have all been .218", that puts the center @ .109" from the edge of the hole....

(using a .125" rod in the pivot hole of the hammer) my math shows this will give a 3.9 degree angle......use the trig function on a scientific calculator to figure these....

it seems to me that the minimum angle needed will be determined by the amount of slack of the hammer/sear on their pins....the tighter the fit, the less angle needed... i do not have any hard numbers on slack vs angle at this time though......


cletus hungwell said:
any pivoting part's 0deg angle has to be a straight line from the center of the pivot point straight out through the edge..... this is the angle that allows sear movement w/o the hammer moving....... we have to add some negative to make up for the slack in the pins/parts.... to get this, we use a 2nd line, a negative angle intersecting the 0deg at the base of the notch......as this line extends past the base of the notch, the material climbs out over the sear nose, and creates the effect of the springs forcing the sear deeper into the notch....... the amount of angle, and the depth of the notch are selected based on intended purposes of the gun/group.....
Some angles to experiment with...
cletus hungwell said:
or, to get the desired angle, use .004" over center per deg....

0deg=.109", or 7/64's
1deg=.113", or a #33 drill shank
2deg=.117", a #32 is .116", add .001 shim under it!
3deg=.121", a #31 is .120, so, add a thou of shim stock....
4deg=.125"

these are approx figures...shim between the pin and the vise to get additional angle adjustments......

later
cletus
cletus hungwell said:
i'm really amazed, and thankfull to all here, for all the help and knowledge so freely shared.... and, i get a special kick out of pitchin in an idea from time to time.....
I couldn't have said it better myself and Thanks to You cletus for helping me understand this whole "sear notch -angle - engagement" thing.

These quotes were taken and edited from the "My Hammer Grinding Jig" by batmanacw and hijacked by cletus, Markbo, J57ltr, a few others and myself :hide:

If you try this method Please post your results!!!

Good Luck & Thanks, MorlyKrupt
 
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#77 ·
Saying that this stoning method is somehow unsafe or wrong is just silly.


Oh, now I've done it, here they come.
I didnt' say the stoning method was unsafe or wrong. I simply stated that changing the angle is unsafe, depending on how much your change it. The reverse cam action is there for a reason, just like AR duty triggers have.
My hammer hooks and sear noses are much more square than the ones in the photos earlier in the thread.

Put the Kool Aid down and read......
I've posted my proven and functional experiences.
If I've stepped on some toes so be it, grow up.
 
#78 ·
If Volquartsen uses a negative angle, then they must be really, really unsafe then?

This dog doesn't hunt! It barking up the wrong tree!

I have no problem with people critical of my ideas or methods. That is part of life. I am confident that folks will be able to make up their own minds and decide for themselves. Just don't step on well respected toes like those of Cletus and not expect to get called on it. Using a word like "unsafe" is as inflamatory as it is incorrect.

That is like saying that my work is endangering someone I care about. Somehow, my nefews are in danger because they shoot my rifles with my work done to the triggers. You can see how that could be a touchy subject, especially when its wrong. Can you see how this could be considered insulting?
 
#79 · (Edited)
We are all about the "small stuff" here. Lots and lots of small stuff that combine to create a semi auto rifle that puts up sub .200" 5 shot groups at 50 yds. on a regular basis. We can be a touchy lot!

I'm not mad or anything, just mindful of the work that others have done. Your opinions are welcome and I hope that you continue to share them. Don't want to discourage discourse, just avoid misunderstandings.

"If you stone the angle you are stoning away a safe condition"

This could be misconstrued as a direct inditement of our methods as being unsafe. This is just what I was refering too as maybe a little over reaching. I am sure that I misunderstood.
 
#80 ·
MorlyKrupt said:
Shooot I am late... anyways order the 65$ Deluxe trigger kit from Brownells made by Clark Customs and you will find a Stock Ruger hammer that has been reworked using almost the same method explaind here and the hammers are not rehardened. All they did was change the angle from 42deg to 32deg.

Maybe someone should call Brownells and tell them that the kits are unsafe.
Hey maybe you guys with 2 to 3 posts per day should also read the posts.
I said that changing the angle creates a possible unsafe condition. So does reducing the radius if you go too far. I've changed the angle and have had good results, however, I've had better results by reducing the radius and polishing the engagement surfaces. I'm sure not all factory hammer notches are cut exactly at the same angle, believe me I know, I've gone through my share of them to find what works.
The negative cam, no matter how much you have, was built in to make the trigger safe. It's a safety feature, you can't argue that. Yes, it does contribute to the lousy pull you get on stock groups.
I post in this thread to say I've had good results by another method and I get jumped on. I'm not commenting from my armchair or any other chair, I've made money from my trigger work. How many of you can say the same thing?
You can have your group mentality, I thought this was all about the open discussion of ideas and experiences. I haven't insulted anyone or condescended. You guys want to drown out people that disagree or offer alternative ideas, go for it.
 
#82 · (Edited)
hags said:
Hey maybe you guys with 2 to 3 posts per day should also read the posts.
I said that changing the angle creates a possible unsafe condition. So does reducing the radius if you go too far. I've changed the angle and have had good results, however, I've had better results by reducing the radius and polishing the engagement surfaces. I'm sure not all factory hammer notches are cut exactly at the same angle, believe me I know, I've gone through my share of them to find what works.
The negative cam, no matter how much you have, was built in to make the trigger safe. It's a safety feature, you can't argue that. Yes, it does contribute to the lousy pull you get on stock groups.
I post in this thread to say I've had good results by another method and I get jumped on. I'm not commenting from my armchair or any other chair, I've made money from my trigger work. How many of you can say the same thing?
You can have your group mentality, I thought this was all about the open discussion of ideas and experiences. I haven't insulted anyone or condescended. You guys want to drown out people that disagree or offer alternative ideas, go for it.
hags... looking in with no dog in this hunt, you HAVE insulted and been condescending to everyone who has discussed it with you. They are taking their own experiences and told you what they have found. You have said you 'could probably' and shown nothing other than you know a different way to do it, which by the way is no secret here. I happen to believe that JUST radiusing the hammer will not produce a good trigger. Better maybe, but good? I don't think so.

You condescend by remarking about someone's post count to initmate he thinks he is an expert and the herd mentality, which is insulting to everyone.

Then you tell people that what they have done (by changing the engagement angle) is unsafe and refer to an AR trigger...for what? They have nothing in common. Changing that angle is done by Clark, Volquartsen, Briley and most gunsmiths who actually DO 10/22 trigger jobs. In fact I have an AGI video that shows that exact detail - as well as stoning the radius as you describe.

My point being... claiming innocence and being attacked is not accurate. You are not a vicitim here. You disagree with what they have found? Show us. You got a better idea? Show us. Otherwise you are just being an instigator.

The fact that you have made money on your trigger jobs means... oh... nothing. I have DONE what Cletus, batman & the others have talked about so I KNOW - not from guessing, but from personal experience that it works... it is safe... and it has remained so for a long, long time and thousands of rounds of shooting.

I am afraid you simply cannot argue that because it is my personal experience. The fact that any TG modified too far can be unsafe is a no-brainer, but that is with ANY mod. You intimate that it is more unsafe with their mod than yours. But again... you offer nothing to back it up.

Methinks there is a Troll among us.
 
#84 ·
Hang on, hags............

I'm always interested in something new. Maybe thats why I now have so many spare parts laying around :D . From what I gathered, your modifications consist of polishing/slicking-up all of the engagement surfaces and stoning off some of the lobe on the hammer. If I've missed something else that you do, please advise.

Now being a tinkerer of these 10/22 triggers, I'm sure you are doing some more stuff that you're not tellin' us. So let's have it. What other mods are you doin' in addition to what I stated above?

H'fly
 
#85 ·
That's about it, I have changed the angle in conjunction with reducing the radius but haven't had such good luck.
Like I alluded to I have noticed a huge difference in the angle on stock hammers, maybe I've been lucky.
I can tell you this, if you've ever used a VQ hammer, and all they do is change the angle, the pull is not so good. It's full of creep and pretravel, at least the few examples I've used.
No, I'm not suggesting anything, it's been my experience that the ultimate would involve both a slight change of angle and a drastic reduction in radius.
Having said that, I can achieve satisfactory results with just the reduction of radius and polishing of both the sear and the hammer engagement areas.
DO NOT as others have said, round anything, this will not only degrade function but will feel like total crap.
 
#86 · (Edited)
And that is exactly why I have been asking for pictures. Reducing the radius ... where... of the entire bottom of the hammer? You say drastic... but how much is drastic? What is the net result measurement of the back & bottom of the new hammer face as measured to say the bottom of the cross pin hole?

All of us take great pains in the polishing department so all of that is a well known. In fact polishing the hammer and sear is not nearly enough. Nor is sticking with factory pins. That is why we want to see your ideas.

If you can take pics and send them to me via email I would be happy to host them and post them for you here.

Please let me know how I may be of service.
 
#88 · (Edited)
this should be agreed on as the area to reduce the radius


then we can measure the engagement area.


I usually take a safe amount of .010" to .015" off of the radius/engagement area. I havent gone past .015" so I haven't been worried about leaving too small of an engagement area.
please take measurements before and after...:t and post them too.
 
#89 ·
Great all that just for reducing the engagement on the hammer that has already been discussed. This is why I asked for pics, when I think of reducing a radius I think of rounding the entire hammer base on the hammer for some reason. Instead if just removing enough material from the hammer to do the same thing. They say pics are worth 1000 words.
 
#90 ·
Exactly. What Morly posted has been discussed here for years. JUST reducing that radius does NOT improve the trigger pull to the extent that also changing the engagement angle does. We have all done this for a very long time and know the results.

Morly - and everyone. My apologies for being a part of the bickering. I was trying to get a point across to no avail.
 
#91 ·
I hope I have taken enough of the destructive portion of this thread out to get it back on track without depriving anyone of any important information.

Folks, this is a wonderful informative thread. If you cannot contribute positively to it, please refrain from posting.

Thanks.
 
#92 ·
J57ltr, You will want to grind the entire radius on the bottom of the hammer if you can pull it off. The reason is the fact that the sear isn't pushed away from the engagement surface at all during the rotation of the hammer. Putting a .218" (I think that this is right, someone correct it if I forgot) drill bit in the machinist vise, pointing up. Then you can put the hammer on it and rotate it against a grinding wheel. This can radius the entire bottom of the hammer. Make sure that the hammer bottom is radiused square though. This is best done on a surface grinder.

The shorter jump the sear has to pop up, into the hammer notch, the better chance it has of making it there in time to reset reliably. Many aftermarket and stock hammers are rough to say the least. I like them nice and smooth.

Does this clear things up for you?
 
#93 ·
Thanks Morly, Markbo, Admin, for cleaning up this posting. I think should be a sticky, but before that, do you polish up your hammer after all the stoning? If so, or not, what would be a good all purpose polish to use on steel parts? Thank you gentlemen.

reid
 
#94 ·
This is where I am a little too brave for most folks. I use white or pink cratex in my dremel to polish until almost all the tool marks are gone.

Doing this by hand and still maintain the angles and not rounding it off, is very tough and takes a huge amount of patience. I like to use progessively finer stones and then finish this way. Next gun show, I will be picking up a 1500 grit stone and finer if I can find it! The farther to polish you can go with a flat stone, the less you have to polish to get the mirror you want. Others here will have better ideas to use without a dremel.
 
#95 ·
After all stoning I do polish the hammer further, in addition to everything else. I go really all out on polishing... the sides and both sides of the inserts, the oversized cross pin, the top of the hammer where it contacts the bolt the bottom radius. Even the shelf to remove tool marks. I polish everything in there I possibly can.

I use a large lighted magnifier on my bench and a dremel for the polishing. Since I am not removing material I find I can control it just fine. When stoning, I canNOT use paper... I have ruined a few hammers trying it. I must use a stone for the control.
 
#96 ·
batmanacw said:
J57ltr, You will want to grind the entire radius on the bottom of the hammer if you can pull it off. The reason is the fact that the sear isn't pushed away from the engagement surface at all during the rotation of the hammer. Putting a .218" (I think that this is right, someone correct it if I forgot) drill bit in the machinist vise, pointing up. Then you can put the hammer on it and rotate it against a grinding wheel. This can radius the entire bottom of the hammer. Make sure that the hammer bottom is radiused square though. This is best done on a surface grinder.

The shorter jump the sear has to pop up, into the hammer notch, the better chance it has of making it there in time to reset reliably. Many aftermarket and stock hammers are rough to say the least. I like them nice and smooth.

Does this clear things up for you?
I understand it fully I just didn't understand what Hags was saying, I was confused since we had already discussed the hammer hook.

Jeff
 
#97 ·
I finally got around to trying these mods. I am VERY pleased with the results. :t I reduced the hook angle and radiused the entire botom of the hammer then done the jb weld trick and polished all contact surfaces with flitz and a dremmel. I don't have a trigger scale but I would estimate it to be around 2.5-3#s with no noticeable creep or take up. Add a homemade auto bolt release and extended mag release and I have one fine trigger assembly for practically nothing except for a litle time.
I used a regular vice not a machinist vice and a small file to do the hook and did the radius on a bench grinder with a steady hand :rolleyes: I'm quite surprized how well it turned out. I would recommend this procedure to anyone who is on a tight budget with a few tools lying around.

Thanks for the instructions Bro :t,
swampf0x
 
#98 ·
Markbo said:
After all stoning I do polish the hammer further, in addition to everything else. I go really all out on polishing... the sides and both sides of the inserts, the oversized cross pin, the top of the hammer where it contacts the bolt the bottom radius. Even the shelf to remove tool marks. I polish everything in there I possibly can.

I use a large lighted magnifier on my bench and a dremel for the polishing. Since I am not removing material I find I can control it just fine. When stoning, I canNOT use paper... I have ruined a few hammers trying it. I must use a stone for the control.
Mark, do you polish the shelf and sear edges too? That would seem to me to be counter productive - as you'd want a very clean (not radiused) edge for a crisp let off.

I definitely need to get into the habit of polishing - going that extra distance, but getting the proper angle down seems like it gets you about 90% there.
 
#99 ·
I polish the sear shelf that the hammer radius engages, the back end where the disconnector engages and and I just touch the front ege to make sure there is no small hiccup there. I believe that the human hand has amazing sensitivity and a sharply cut, squared fingernail edge can find imperfections that I cannot see. When I feel one, I buff it away.

I do everything that I think touches anything. The pins, both sides of the hammer spacers, the sides of the hammer. I even go so far as to polish it in the turning direction. By using a dremel you can put rouge on the flat surface and then engage the larger pin hole so the holding screw goes into the hole and the polishing direction goes in a circle around it. I always try to make the final polish in the direction of engagement of any part.
 
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