1911 assembly question

[Madhouse]

I'm working on a new build and am hung up on assembly.  When I get the mainspring housing pinned and cock the action, I drop in the thumb safety.  After that, I can’t get the hammer to return, the trigger is completely locked out.  If I just take the thumb safety out and let the grip safety hang loose, the trigger will action the hammer.

 

I’ve tried several different mainsprings and several different grip safeties, to no avail.  Can anyone help me with what’s catching on what?

 

Thanks all, appreciate any input.

[Armed Eye Doc]

@392heminut

 

[Madhouse]

Thx for the reply.  No sir, I have the disconnect and sear oriented correctly.  And this is a series 70 configuration.

[shooterrex]

Even without the thumb safety installed the trigger will cause the hammer to fall without depressing the grip safety? Grip safety is not fit correctly. Trigger should not be able to move rearward without the grip safety being depressed. Fix that first.

[98Z5V]

11 minutes ago, shooterrex said:

Even without the thumb safety installed the trigger will cause the hammer to fall without depressing the grip safety? Grip safety is not fit correctly. Trigger should not be able to move rearward without the grip safety being depressed. Fix that first.

I've been through that hell, working on a 1911 for my Gun Pusher. The grip safety tang was filed too short by someone else, before the gun ever came in to the shop.  Gun owner claimed ignorance that he had someone else work on the gun.  Ordered new grip safety-and my hell has been trying to match that fucker to the radius on the frame, and still make it work. 

[392heminut]

Grip safeties can be the shits to fit! Right now, I think Madhouse is focusing on the thumb safety issue.

This is extremely hard to diagnose without the gun in hand, you're dealing with some very intricate fitting of several small parts there. Is this a new build with all new parts? I recently fitted a new safety in a new build and ran across a similar issue. In all the years of smithing 1911s I've never had this one pop up. It was doing the same thing you describe. There is a small scallop cut just above the protrusion on the thumb safety (the part you have to file to fit) that engages the sear when applied. That scallop lets the bottom corner of the sear move back when the safety is in the down position. The safety I was fitting (a Bill Wilson ambi) was causing the problem you described. Turned out the scallop hadn't been cut deep enough to allow the bottom of the sear to come back far enough to disengage the hammer notch. A couple of swipes with a 1/8" carbide bit in the Dremel to deepen that notch solved that issue. It didn't take much.

Take the grip safety off and reassemble the gun with the thumb safety and you can see in there to kind of get an idea what is taking place. This will also rule out any chance of the grip safety being part of the issue.

[Madhouse]

392 - wanted to follow up on this, I indeed needed to work down that spot a bit that you described  as a scallop. 

 

I'm functional now.  That was a nice trick to learn, it hadn't show up in previous builds.  On to the next, I'm trying to get 5 more built in my precious little spare time.

[392heminut]

Glad you got it sorted out! 1911s are my forte but 308ARs not so much, that's how I ended up here!😝

[Madhouse]

Me as well, love the 1911 platform.  I can't believe how difficult it is to find an armorer's class.

[392heminut]

On 2/28/2021 at 10:35 AM, Madhouse said:

Me as well, love the 1911 platform.  I can't believe how difficult it is to find an armorer's class.

I was lucky, I had two first class pistolsmiths in the same town I live in that were happy to coach me when I first started.

Edited March 5, 2021 by 392heminut

[Madhouse]

You'd think I could find something in the Houston area, but no joy.