1944 (or so) 1911 thumb safety issue

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squarooticus

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I have recently acquired a c.a. 1944 1911 mongrel that seems to have only one obvious problem: sear movement with the thumb safety engaged.

If you enable the thumb safety and then grip the gun and pull the trigger, the hammer falls off the sear and safely impacts the bar on the thumb safety. The thumb safety is now well nigh impossible to disengage without re-cocking the hammer: I have applied a lot of force, and there's no way the hammer is getting any closer to the firing pin without being recocked. Looking at it with a small flashlight and the grip safety out, it's pretty clear that geometry is the real safety here: unless two metal pieces find a way to pass through each other, the hammer is stuck until the thumb safety is disengaged, and the thumb safety is stuck until the hammer is re-cocked.

However, my impression is that there should be no sear movement when the thumb safety is engaged: even though I am now more confident than ever in the safety of condition one carry---this gun was incredibly well-designed safety-wise!---I would still rather the hammer stay cocked while the thumb safety is engaged. My S&W 1911PD has no appreciable sear movement when the grip safety is disengaged and trigger is pulled while the thumb safety is engaged.

Any suggestions on what the problem might be and how I would fix it?

Thanks,
Kyle
 
You are correct in thinking that when the safety lock (manual safety) is engaged the sear should be blocked and not move. If there is enough movement to allow the hammer to release when the trigger is pulled the hammer should be caught in the half-cock notch so that it doesn't go all of the way down. The condition might be caused by lowered hammer hooks (full-cock notch) done by someone trying to "improve" the trigger pull, a damaged sear, or out-of-tolerance safety lock lug.

A pistolsmith that is experienced with 1911 pistols can possibly fix the safety lock lug by peening it with a hammer, but only if it is a genuine USGI or older Colt commercial part. Otherwise the safety lock will need to be replaced with a new one, and some minor fitting will likely be required.
 
Ok, so it looks like I'll need to find a good gunsmith up near where I live. It was bound to happen eventually anway.

Of course, given how much this particular gun weighs (it's gotta be at least 2-1/2 pounds), it's not clear it will ever be used for more than recreational shooting. Then again, I may decide that if it was good enough for the Army, it's good enough for me, in which case I'd want it in flawless working order. That is, if I can figure out how to suspend it on myself without looking like my pant legs are different lengths. :D

Cheers,
Kyle
 
Just to update for others potentially in the same situation: check the sear spring.

I took the gun apart and thought the sear spring looked a little odd. I then compared it to the one in my S&W and noticed that the center finger was bent the wrong way, i.e., back towards the grip safety! How it got into this shape is beyond me, and the story may be 50 years old and long lost.

Reshaping that finger so it matched the S&W's fixed the problem. Now as long as the safety doesn't travel too far upwards---which it can't when the slide is attached to the frame---the lug on the safety successfully blocks any sear travel when the trigger is pulled.

Cheers,
Kyle
 
The center part of the sear spring pushes on the disconector, which in turn presses on the trigger. It is quite probable that someone bent the spring in an attempt to lighten the trigger pull. The left side of the spring tensions the sear, and the one on the right (bent backward) pushes on the grip safety.

If some previous owner has bent up the sear spring, don't try to re-bend it, but rather replace it. The one you have may now be messed up enough so that the disconector won't work right.

To check disconector function: After being sure the pistol is cleared of cartridges, hold the trigger back while lowering the slide. The hammer should not follow down. Continue to hold the trigger back while racking the slide back & forth. Then release the triger and pull it again. This time the hammer should fall.
 
Hmmm

I'm tryin' to wrap my head around howzcome tweakin' the center leaf of the sear spring would keep the thumb safety from movin' up too far...and how it "fixed" the issue of lettin' the hammer fall. If the safety moves up too far, it can allow sear movement, but it shouldn't move up any further than the
notch in the slide will allow unless somethin's outta whack.

I'd like to see this one...:scrutiny:
 
Old Fuff said:
To check disconector function: After being sure the pistol is cleared of cartridges, hold the trigger back while lowering the slide. The hammer should not follow down. Continue to hold the trigger back while racking the slide back & forth. Then release the triger and pull it again. This time the hammer should fall.
I already checked this, and the disconnector works fine.

But you are right: I should replace the spring rather than rely on one that only "looks" right.
1911Tuner said:
I'm tryin' to wrap my head around howzcome tweakin' the center leaf of the sear spring would keep the thumb safety from movin' up too far...and how it "fixed" the issue of lettin' the hammer fall.
I agree that it doesn't make sense, but then I am only an amateur: I'm reporting mostly empirically, with only a few hours worth of mechanical understanding of the action. If I am able to figure it out, I will let you know.

Kyle
 
I'll second (or third, or whatever we're up to by this point) replacing the sear spring. In fact, put a full spring kit from Wolff in it before you take it to the smith. They're under $20, and that way you don't have to worry about how many rounds those springs have seen, and the smith can do any tweaking you want with newer springs. It's disappointing to say the least, when you've got the gun just the way you like it and a 50+ year old recoil spring or mainspring needs replacement, then you get to find out just how much lighter than a new factory spring it had become.

As far as carry, there are lots of good options out there. My personal favorite is the one I reveiwed in this post. Add a good belt, and the 1911's weight just ceases to be an issue.
 
Agreed on all points, KD5NRH, though I think my main objection to the weight is not discomfort resulting directly from lugging an extra 2-1/2 pounds, but that heavy guns tend to pull down one side of my pants, making things all sort of dislocated and longer-term uncomfortable. I will not get any more specific. :)

Maybe I just need to balance it with three or four full magazines on the other side. :evil:

And thinking about it further, these must have been two different problems: it is impossible for the safety to be working now and yet broken in the way I suspected earlier, as the sear merely pivots: there is no way for it to move any other way. Thus, I must have been testing the safety with the slide off, even though I could swear that I tried it both ways. Oh, well: I'll chalk it up to inexperience.

Kyle
 
re:

Kyle...Try it again and do it just a bit different this time.

Gun assembled(Empty gun!)...Safety on. Pull the trigger about twice as hard as you normally would to fire the gun. Hold the left side of the gun up to your ear...next to the safety. Slowly, pull the hammer back past full-cock. Don't let it hit the grip safety. Listen carefully for a light "click" sound. If you hear it, the sear rotated and is resetting back into the hammer. If you don't hear it, the safety is blocking sear movement, and all is well.
 
Kyle...Try it again and do it just a bit different this time.
Done. All is well: no click.

Nonetheless, I have one of those Wolff spring kits on order, because I want a proper sear spring and because both the recoil spring and the mainspring feel weak.

Kyle
 
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