Stoning A Sear "at An Angle"

[Sixgun]

I the topic titled "Ultimate 1911 Trigger Job" our host, Mr. Enos made a reply about stoning the sear at an angle. I used his advice on using a blue marker and seeing if I had perfect sear nose, hammer hook engagement. I do not, it looks as if one hook is doing the majority of the "holding".

I understand the concept of what Brian was saying, but do not know how to achieve stoning the sear at an angle. I was wondering if this was done freehand, or on a jig with shims of various thickness under the stone on the"low side" of the sear.

My trigger pull is at 38 oz. I'd just feel better if everything was perfect. I'm of the opinion if that's what will hold a trigger job at sub one pound for a year or so, then doing it at 38 oz. should last several years.

Thank you.

Ray C.

P.S. I'm using a Koenig hammer, and C&S low mass sear and disconnector, in a STI frame.

[blkbrd]

I have yet to meet someone who can cleanly stone the primary angle by hand.

You can mount the sear in a fixture and clean up the contact angle with a fine stone.

[wide45]

Welcome to the Forums.

Scroll down, Benos explains how he does the sears without a jig, and talks a little about the uneven contact pattern. He also mentions that you should expect to trash some parts while learning this method.

http://www.brianenos.com/forums/index.php?showtopic=5927

[wide45]

It is possible to put the sear in a vise or machinist's clamp, so that the tip of the sear is even with the top of the jaws. It is very important that the flat angle of the sear is parallel with the top of the jaws. The idea is that running a stone across the top of the jaws will polish the sear without changing the angle. A very small error will have a big effect. Use the sharpie. Use a magnifing glass. Don't try to remove metal. Favor the high side. Just a few light strokes should do it. If you think for one moment of using power tools, this job is way over your head. Don't start if you don't understand and accept, that there is a good chance you will ruin it.

All the gunsmiths are cringing. Don't fool yourself.

[JD45]

Since a good many IDPA competitors shoot Kimber .45s (me too, of course), let's hear some tips on the best 1911 trigger job for IDPA. And I mean the old timey way, no jigs, just trial and error. Should we replace the MIM type parts? How light of a mainspring? Sear spring bending worries me. Is it required? What is the proper hammer hook height for us ham-handed home gunmiths like me that want a 3lb. trigger. I stoned the hooks to .023" and polished everything in mine, but I found that 5000 shots did more good than my smith'n. It breaks at about 4.5lbs. now, but with everyone's help I think it can be improved.

[tightloop]

JD45

I try to be a frugal as the next guy, but everyone has to decide if they are capable of becoming a brain surgeon by correspondence, a space scientist over the internet, or doing their own pistol modifications.

Understand this: if your gear (pistol, mags, and ammo) run 100% of the time, and you only have a fair match, you will beat the 50% of the shooters, those who's gear laid down on them.

Just speaking for me, it is worth every cent I pay to KNOW that I have quality, reliable gear that's going to work every time I LAMR. To answer the question you are wanting to ask, NO, I don't repair my own vehicle, am not a a home repair kind of guy, but I am a guy who knows he cannot perform a great trigger job on my 1911.

My suggestion is to get to know a quality pistolsmith really well, and help support him. Worth it in the long run.

Just my .02 worth.

[JD45]

The big reason that I want to do my own trigger jobs is because many of our local smiths don't seem to know much about 1911's and I like to fix things right when they break. Paying the stinkin' UPS fees sucks( if I lived near Wilson's or Sweeney's I wouldn't have this trouble). However, you are correct.....I give people the same advice. I'm just hard-headed. I can't stop tinkering.

[Powder Finger]

The concept of changing the angle from one side to the other is usually acomplised

by just favoring the side you need more removed from. IE: once the engagement

angle is correct if you need more off the left you just put your index finger on top

of the stone on the left side as you remove metal.

This won't seem like much but many times the angle you trying to get can't even be measured as it's so slight.

Hope that helps.

[benos]

I always hesitate to open this subject because it's impossible to fully transmit it on the internet.

I had the good fortune to experience a few days (early '80s) as a journeyman with the original master of the freehand technique - Jack Breskovich. But even with patient guidance and hands on instruction, it took many years before I became competent enough to do the trigger jobs I can do today.

Like Powder Finger said, it is simply a matter of "favoring" the side of the sear that is about a zillionth of an inch too long. But even after much experience, this should be done carefully, checking the contact pattern frequently.

With proper sear nose/hammer hook geometry, as found in factory SVI pistols, the actual contact pattern is not that super-critical, until you try to get a trigger job that is 100% reliable all year long at 16 ozs, on a stock gun.

I DO NOT RECOMMEND EXPERIMENTING WITH THIS TECHNIQUE AT ALL.
It's just too much of a safety issue. I do recommend following tightloop's advice, find a qualified pistolsmith and support him. Almost any good pistolsmith can do a 2 to 2.5 lb., reliable trigger job, which is all you need.
be

Added 09.10.14, from a PM:

If I am understanding correctly, you are stoning the sear to have a negative angle engagement with the hammer hooks. Do you also cut the hammer hooks to match the sear angle?

No, you never touch the hammer hooks.

And I'm not sure what you mean by "negative angle."

But here's the goal... The shape of the sear nose needs to be such... If you have the frame clamped into a bench vise, with the tip of a dial indicator on the back of the hammer... as the trigger is pulled until the hammer is released - the dial indicator never moves.

The number two key factor, in a nutshell - the sear has to have perfectly even contact across both hammer hooks. A blue Sharpie Marker (not any other color, or any other type of marker) applied to the sear nose (before installation), will tell you this upon inspection when the sear is removed.

After a very long time of practicing stoning the sears by hand - never could make a jig to do it - you can learn to replace the dial indicator with your right hand's thumb and forefinger, so you can feel if the hammer is cocking or de-cocking when you press the trigger to the rear, using your left hand's thumb an forefinger.

Accomplishing the above is definitely an art form. And really not something that can be comunicated by typing. It took years of practice before I felt I had mastered it.

be

[bountyhunter]

"Should we replace the MIM type parts? "

Not unlss there is a problem with them.

"How light of a mainspring? "

About 18#

" Sear spring bending worries me. Is it required? "

Adjusting the pressure of the left and center leaf primarily determines trigger pull weight. It can also cause multiple fire or full auto in some cases if too light.

"What is the proper hammer hook height for us ham-handed home gunmiths like me that want a 3lb. "

Not less than .020"

"Since a good many IDPA competitors shoot Kimber .45s (me too, of course), let's hear I stoned the hooks to .023" and polished everything in mine, but I found that 5000 shots did more good than my smith'n. "

Makes sense.

" It breaks at about 4.5lbs. now, but with everyone's help I think it can be improved. "

I've done a lot of different triggers and I think the 1911 is the one I would say do not even attempt without a jig and experience. The reason is that the sear face has two cuts (primary and relief) and they are critical to getting no creep and good hammer capture. Another point is that the sear face wears and MANY 1911 trigger jobs work for a few thousand rounds and then start having hammer follow because the sear face wears slightly and the relief cut was made too far up the face. I fiddle with guns shemlessly, but I would never try a 1911 trigger job because I don't have the setup.

[Sixgun]

Thanks for the replies everyone. I'll take Brians advice and leave well enough alone. i ran a couple of hundred rounds through the gun and cleaned and oiled all components. I just checked the trigger pull and now it's at 36 oz. It feels great!

Thanks again everyone.

Ray C.

[Jasonub]

on a similar note, I stoned my sti hammer too much. Can I stone the lower part so that the hooks go back to .020?

[benos]

That's tricky stuff, best left to the Masters, or a friend with a nice, fine wheel on a surface grinder, and who knows how to use it. Unless you're very talented with a stone you'll probably ruin the hooks trying to make them deeper. At any rate your probably money/time ahead to buy another one. Oh wait, I sell the super-trick SVI, be.com design, hammer on my site. Really, I just thought of that as I was finishing typing this thread.

[Jasonub]

thanks for the response Brian. Super trick svi hammer? Whats that and how much???

[Sixgun]

jason,

Go to BE's store and look at the SVI stuff. It's there. Nice looking hammer and sear combo.

Ray C.

[38super]

Be careful cutting hammer hooks deeper, causes the sear to rotate a little more to fully engage the hammer hooks. Might cause a thumb safety issue, like tap the trigger, thumb down safety and hammer falls. Real interesting during a holster draw. Over worked sears get shorter and cause this prob too. Remember, I might be your RO next time, I like my feet.

[Jasonub]

jason,

Go to BE's store and look at the SVI stuff. It's there. Nice looking hammer and sear combo.

Ray C.

I think Brian mentioned that he is about to offer it and not offering it right now. Thanks for the help though

38 super, dont worry, I shoot in the Philippines and I dont think I can join the world shoot yet

[Flexmoney]

Click HERE for a link to Brian's page with his signature SV hammer (and sear).

[Jasonub]

Thanks flex