1911 Trigger

[Win52D]

Hi Guys
I'm new to THR. I'm glad I stumbled across this forum...lots of interesting posts here.

I have a question. I started installing a few parts on my SA 1911...better trigger, extended slide stop, extended thumb safety. After getting everything fitted I noticed that every third or forth time a dropped the slide (with a dummy round of course) the hammer would drop to half cock. I thought maybe the thumb safety was causing but then I noticed the new trigger.

The back of the loop where it contacts the disconnector was standing proud of the back wall of the magazine well by .020". The original sat just a bit below flush. The new trigger loop is about .030" longer.

I'm guessing here that the extra .030" is causing the sear to barely connect with the hammer and that during the slide drop it is jarring the hammer loose.

My question...what is the easiest way to fix this? Is there some extra fitting needed or sholud I try a new trigger?

 

[Win52D]

The trigger is from Cylinder and Slide. I thought a few pics might help.

 

[Gunner4h1r3]

I would say go with a new trigger. I installed an adjustable one made by Wilson that fit both my Colt 1991A1 Compact and then My Rock Island GI. Both worked equally well.

Unless you have some experience with modifying the trigger bar, I'd say go with a new trigger or send it to a 'smith.

 

[Eric F]

In the pictures, are the triggers sitting as far forward as they can?

If so messing around with trigger bows can be tricky. I would say but a diffrent trigger. If you want the challenge though you can fix this trigger its difficult and I have never done it correctly, after 2 hours I just ran up the road and bought a diffrent trigger.

 

[sniper350]

What you have is a very dangerous situation here .........and one of the first things a Gunsmith would check before ever considering firing the weapon.

Your 1911 could go bang when you least expect it, like loading it up in your home.

The trigger BOW must be flush or a little lower than the frame inside its channel. I would try a different trigger, as I don't know how to shorten the trigger Bow's length that you could easily accomplish. Just make sure the trigger you have is FULLY seated forward .......and not being held up by the trigger shoe & frame. This weapon should be examined by a qualified Gunsmith before live rounds are ever loaded up. Other things might be a miss & that's why you have trigger fitment problems.

JF.

 

[rcmodel]

Blacken the trigger bow with candle soot and then seat it in the frame and give it a tap on the back to make sure it's fully seated.

Now take it back out and see what is hitting what and stopping it.

Could just be a bur in the trigger channel holding things up from fully seating.

Or it could be an out-of-spec frame or trigger.

rcmodel

 

[Win52D]

Thanks guys. I suspect the trigger may be out of spec. With the original trigger installed it sits below flush. In some 20 years and 50,000 rds of use I have never had an issue. I'll find a local 'smith to give it a once over.

 

[1911Tuner]

*sigh* tsk tsk...

The trigger bow is too long for the frame. No way of knowing if the frame is out of spec...or the trigger.
We'll assume that it's the trigger.

The trigger doesn't bear on the sear. It bears on the disconnect, which in turn presses on the sear. This is why SA autopistols like the 1911 need a little takeup...or pre-travel..before pressure is applied to roll the sear away from the hammer hooks. Removing that pretravel can result in the problem that you're having.

Why?

Inertia. Newton's Law that says whatever is at rest tends to remain at rest.

When you drop the slide, it's propelled forward by recoil/action spring. The slide is pretty massive...and during the trip, it builds up a lot of momentum.

Then, when it comes slamming to a stop, it jerks the frame hard forward.
The trigger...obeying Mr. Newton...stands still, and bumps the disconnect...or rather the disconnect bumps the trigger stirrup...which in turn bumps the sear...which escapes the hammer hooks, and quickly resets and grabs the half-cock notch. The half-cock saved you.

Other factors that contribute are hammer bounce...inertia again...and the hammer compresses the mainspring a minute amount. Full tension from the mainspring is reduced, making it even easier for the trigger to nudge the sear out of engagement. Not a major factor...but a minor contributor.

If the gun has had a trigger job...with reduced mainspring strength, shortened/squared hammer hooks, and tweaked sear spring to lighten the load resisting the trigger...it all adds up to what you're experiencing.

It's less likely with light, aluminum or plastic triggers...more likely with heavy steel triggers.

Less likely with lightened or skeletonized hammers...more likely with stock hammers.

Your problem, however...is caused by lack of sufficient trigger pretravel...which is generally accepted to be .040 inch minimum. I like to see about .050-.060 inch...but that's just me.

The trigger stirrup shouldn't protrude past the frame wall by more than just a few thousandths. With what you have, you may also run into the stirrup lifting the sear spring off the disconnect...which can cause burst fire or unexpected full auto...or failure to fire...or anything in-between.

Put the stock trigger back in the gun until you can find one that doesn't stick out past the frame wall so far.

 

[Win52D]

1911Tuner..great info as usual With the exception of a new trigger the rest of the action parts are original, Once I saw the stirrup sticking out of the frame I put the original back in. I'm hoping the trigger is out of spec...the alternative sounds a bit expensive to fix

 

[1911Tuner]

I'm hoping the trigger is out of spec...the alternative sounds a bit expensive to fix

That's probably what it is. I'm not gonna say that I suspect that some triggers are made purposely long in order to reduce takeup...but given the recent trends, nothin' would surprise me.

 

[Win52D]

Considering that there was no take-up and the trigger felt light and crisp I was thinking that too. Although having an unsafe pistol doesn't seem like a good trade-off to me.

I have a new Wilson trigger in the way.

 

[Win52D]

Follow up on the trigger. The new Wilson Ultralight Match trigger arrived today...just some minor filing and deburring had the trigger in and running smooth. The hammer does not follow the slide anymore.