Finding the right Sear

First topic message reminder :

So I've been studying, testing and learning on how to do trigger work on a 1911. I know, I know .... Send it to someone who knows what they're doing right? But I really want to learn how to do this sort of thing and do it right. Call it tinker-itis if you want but I'd really like to be able to do excellent trigger work for people someday. 

I've mentioned here before that I did get my trigger to have a smooth and clean pull, crisp and clean break, no creep to speak of, and the over travel screw is set perfectly. But I have hammer follow ONLY when using the slide stop as a slide release. This is on a loaded magazine (snap caps not live ammo). And to be clear the hammer follows the slide as the slide goes into battery but the hammer stops at the half cocked position. 

Now if a loaded magazine is inserted into the gun while the slide is in the locked back position, as if I just emptied one mag and exchanged it for a loaded one, and I pulled the slide to the rear and let it go to chamber the first round instead of using the slide stop as a slide release like explained above, then I have no issues. 

Some of the information I've gathered on trigger work was from the article on Brownell's website about a 2 1/2 pound trigger pull. (Link for it below)  In that article it talks about a common problem being hammer follow. It is explained as having too short of a sear and so the sear can not fully and/or properly engage the hammer hooks. The reason the sear is too short is because the pin holes for the hammer and sear in the frame are slightly too far apart it claims. This keeps the sear too far away from the hammer and any work done to the sear I imagine makes this problem more evident. The solution that was talked about was getting a longer sear or a sear with a longer nose. 

Since I have this problem it talks about (not knowing if it's truely due to the sear and hammer pin holes being too far apart or not) I'd like to experiment with trying a new sear but one that is in fact longer. However - and yes here comes the big question and the reason for my post - how do I know if I'm ordering a standard dimension sear, or one that is longer? Are there different sizes or lengths? What Sears do you commonly use or see or hear of pistol smiths using? 

2 1/2 pound trigger - http://www.brownells.com/aspx/learn/learndetail.aspx?lid=10297

Tim:H11 wrote:On the Wolff Spring website they only offered those poundage mainsprings for the Springfield ILS Mainspring.

Hey Tim, I picked one of these up as a tinker-spare for my SA Loaded. Ordered last week, should be in my mailbox tomorrow. If you're interested in dumping the ILS--

http://www.midwayusa.com/product/583572/springfield-armory-mainspring-housing-flat-1911-government-commander-checkered-20-lpi-blue

In my experiment I found that the reduction in pounds in the mainspring only effected trigger pull by 1/4 to 3/8 of a pound and in drastic reduction of mainspring poundage it could effect trigger as much as 1/2 a pound. However I did find that if poundage in the mainspring is reduced too far it of course doesn't hit the firing pin hard enough to detonate the primer. 

If the reduction of the poundage in the mainspring doesn't effect trigger pull too much, then why use 19# springs? That's close to 1/3 less pressure on the hammer? To me - and I'm learning here so forgive my assumptions - that sounds almost too light.

... Unless it has something to do with function.... My guess now is that the reduced power mainsprings are to get the gun to cycle with lighter loads. But if that's the case - wouldn't that be tasked to a lighter recoil spring instead?

Tim:H11 wrote:
... Unless it has something to do with function.... My guess now is that the reduced power mainsprings are to get the gun to cycle with lighter loads. But if that's the case - wouldn't that be tasked to a lighter recoil spring instead?

The recoil spring, mainspring and firing pin stop radius all can be tuned together for lighter loads (even the mag spring can come into play).  The mainspring and firing pin stop radius impact the initial slide speed.  Some light loads may not be able to overcome the initial resistance of a 23lb mainspring and small radius on the firing pin stop.  Some say a small radius keeps the gun in lockup longer, I  haven't done extensive testing but I didn't see a difference when tuning my 9MM for light loads.

- Dave

Jerry Keefer wrote:I looked over this thread twice, getting old and may have missed it, but I didn't see where anyone mentioned measuring the sear..or mentioned a dimension. How long is your sear?? .404  from the primary tip to pin C/L is a very good length to start. As it shortens, from this dimension, things start to go down hill.. ..It's like headspace.. No body knows...  I have measured thousands of sears, and you might be surprised at the number of sears that are too short right out of the box... Heavy handed stoning,  on a super duper sear fixture,  looking for that "magic" angle shortens the sear further..During the advent of the Warner True Radius Sears, the primary makers of sears were consulted and it resulted in sear lengths being held to closer tolerance than in the past.. So many new sears now, will be .404 or slightly longer.  How long are the hammer hooks??  Are the hooks square??  It's new, so the hooks are square and equalized right??  I doubt it.. Do they make equal contact on the primary face of the sear.?? Equal contact can be perfect, or very elusive... 2.5lb triggers on a 1911 is probably not a good place for one's first trigger job. FEW, are the decent quality frames with improper hole spacing...Spring pressure is the least of the issues with a trigger.. It's the combined geometry of all the parts..The disconnector is a very simple device.. The overall length frequently stated is not the final determing factor. The disconnector has a function to perform. Connnect and disconnector.. How much contact in the up position, and how much clearance at the disconnect function does the disconnector have.?? Each can be adjusted. The 1911trigger is really a crude system with a "push" trigger, rather than the conventional "pull" that gunsmiths have fought for decades to function and perform like a precision target system.. It's an up hill battle. Starting with a near perfect sear of .404 makes the rest much easier..I believe I posted a letter some where on the forum, from a Marine Bullseye Team Armorer, which states the challenges and frustrations of the 1911 trigger..

I had a Springfield NM Frame, and when I set the spring to #4 the trigger did not feel right and it had a little creep so I took it to a good gunsmith, a former AMU guy, for a trigger job. Everything was right until about 5th round then the hammer started to follow, I dropped the slid and it went boom all by itself. I carefully repeated the event a couple of times to make sure it was not operator error. 

Deciding to take things into my own hands, I invested in a Cylinder and Slide kit as EGW was sold out of the kit I wanted at the time. Six hours later it followed less at #4, and not at all at #6 but it was still not right. So I sent it to Brandon Bunker, who second only to KC Crawford is one of the best active 1911 gunsmiths I know when it concerns triggers. He said the problem was the hole spacing was too close fixed the problem. Today the trigger is regarded by everyone I know as one of the best crisp triggers on a 1911 around feels like a #2.5 pound trigger and yet it makes weight with NRA weights. 

So the morals to this story are 1) DYI gunsmithing is not a great idea, 2) Your safety check after work should include making sure the gun can hold the hammer at half cock and to make sure the hammer does not follow by using a magazine and a dummy round and dropping the slide. 3) Those NRA 10 commandments work and exist for a reason, 4) Even Springfield can make a NM gun frame that is slightly off spec. 5) If you do feel compelled to touch your gun you will be better served spending time on dry firing then working on the most sensitive parts of the gun.

well DIY gunsmithing is all about choice for me... I've been building my own 1911s for myself and family for well over 30 years...Learned a ton about the gun... still learning.. You can learn to do it but.... you will spend $$ for tooling and then a long time learning how to properly use it. it will cost you $$ for the parts you screwed up.

we don't do it for a living so the learning curve is much longer..  I have a mill and lathe so I can pretty much do what I want.. wish I had a surface grinder but... well maybe someday, but I'm getting old.

I've owned Clark, Maples and Best 1911s in my early years in the sport.. All excellent firearms and learned quite a bit from them. some  of it personally.  we were blessed in Ga. to have some great AMU smiths who retired and stayed here in the 70and 80s.

I still have a Clark long slide but shoot my own Wad guns these days.

I just plain like doing it myself and learning how to..  was it cheaper? 

NOPE

Tim:H11 wrote:If the reduction of the poundage in the mainspring doesn't effect trigger pull too much, then why use 19# springs? That's close to 1/3 less pressure on the hammer? To me - and I'm learning here so forgive my assumptions - that sounds almost too light.

I think you're still confusing ILS mainsprings with normal mainsprings.  Springfield's ILS mainspring is 30lbs stock (and it is also shorter than a normal one, and uses a different mainspring cap).  Wolff sells replacement ILS mainsprings that go as low as 24lbs.  For this setup, a 19lbs spring (if you could find one) would be a 37% reduction in weight.

But a normal 1911 mainspring is 23lbs stock, and people often replace it with a lighter one (21, 19, 18, 17 seem to be popular choices) for bullseye.  Wolff calls them hammer springs, and sells them in a very wide range of weights, from 15lbs up to 34 lbs.  For this setup, a 19lbs spring would be a 17% reduction in weight.

Tim:H11 wrote:If the reduction of the poundage in the mainspring doesn't effect trigger pull too much, then why use 19# springs? That's close to 1/3 less pressure on the hammer? To me - and I'm learning here so forgive my assumptions - that sounds almost too light.

... Unless it has something to do with function.... My guess now is that the reduced power mainsprings are to get the gun to cycle with lighter loads. But if that's the case - wouldn't that be tasked to a lighter recoil spring instead?

It is about function, however, an oversprung mainspring does have a significant effect on trigger pull also.

I like the way my gun functions with the light mainspring, and a heavier recoil spring--all selected to work best with my loads.  The gunsmiths tend to be able to tune a gun better than I can with the stiffer mainsprings.  I do better with the lighter mainsprings.

If the 19# mainspring is enough to make the gun go bang EVERY time, it doesn't matter how many % lower the mainspring tension is except for how the hammer holds the gun in lockup a little harder.