1911 Locking Open - UPDATE

[Quick Draw McGraw]

Hey guys, I have a Citadel 1911 that is occasionally locking open while their are still rounds in the magazine.  Pretty sure it's not my thumb as I kept my thumb clear.  It's not a very consistent problem, but it's a nuisance.  Ironically, some of the time, it doesn't lock open on the last round.

Here's my thought.  I had a gunsmith suggest I file down the part of the slide stop that contacts the magazine a little bit as it may be slightly out of spec and protruding.  He was very specific that he was talking about a thousandth of an inch or two.  Very little metal to be removed.  What say you fine folks?

[cas]

Take the slide off, put the stop in, then a partially loaded mag. Push the rounds up and down to try and see how close the bullets are to touching it.

If it doesn't look close, see where the mag is in relation.

[potatojudge]

Extended slide stop or standard?

Bullet profile?

I suspect your gunsmith is right. A round may be bumping the stop up as it feeds.

The last round not locking should be fixed with a mag spring since the stop itself is obviously capable of catching the slide.

[Quick Draw McGraw]

I was shooting round-nose, 230gr. FMJ. Standard, non-extended, slide stop.

I took off the slide and checked the spacing. It didn't look super close. I filed the edge of the slide-stop by about 3-thousandths of an inch. I also trimmed off a small amount of the plunger spring for the slide stop. Three of the mags I have would not lock open on empty before the spring was trimmed. Two were Wilson Combat 47D mags and the stock ACT mag. After trimming, the Wilson Combat mags locked open, but the ACT mag still won't. I have not had a great experience with the ACT mags in the past.

We'll see next time I head to the range what happens.

[starmetal47]

I'd compare the lip on the magazine follower that engages the slide stop on the offending magazine with the magazines that work well. Never go grinding or cutting away metal as it's easy to cut it away, but hard to put it back, before you extinguish on other avenues first.

[cas]

Jun 23, 2022 2:34:29 GMT -5 Quick Draw McGraw said:

I have not had a great experience with the ACT mags in the past.

I've been beating the skeleton of that long dead horse for years now.

I'll say they all worked well until they split, and they all split. Many P220 mags and one 1911. My 1911 Act mag split without ever having fired a round.
I finally sent it off to Ed Brown's mag exchange program last week. Funny thing is, I almost forgot to send that one, the turdy-est of the turds!

[bigbrowndog]

In competition guns, we would take the slide stop and a drill bit that is slightly larger or same size as plunger and drill a divot into the slide stop where the plunger sits. Just enough to make the application of the slide stop more positive, and cause you to deliberately activate it. It can however delete the natural application of the slide stop on an empty magazine, depending on how deep you make the divot. It mattered little in competition because we always planned our reloads before running out of ammunition.

Trapr

[Quick Draw McGraw]

Jun 24, 2022 7:31:15 GMT -5 bigbrowndog said:

In competition guns, we would take the slide stop and a drill bit that is slightly larger or same size as plunger and drill a divot into the slide stop where the plunger sits. Just enough to make the application of the slide stop more positive, and cause you to deliberately activate it. It can however delete the natural application of the slide stop on an empty magazine, depending on how deep you make the divot. It mattered little in competition because we always planned our reloads before running out of ammunition.

Trapr

I might try this.  My spring mods made the locking open worse.  So...  I may have it looked over by a gunsmith.  When in doubt, hand it to a professional, am I right?

[bradshaw]

"I may have it looked over by a gunsmith. When in doubt, hand it to a professional, am I right?”
----Quick Draw McGraw

*****

“Professional” is term subject to abuse.

A gunsmith with talent, experienced knowledgeable on subject, should be able to sort out the problem. A small deviation in dimension or angle, etc., changes behavior of the whole. If the frame is off in some way or, for instance, the slide stop, or the spring housing has come unstaked, the slide stop could pop up. Holes drilled in the wrong place, cuts made wrong, etc. Job starts with making the frame right, then the parts, and then putting them together.
David Bradshaw

[Quick Draw McGraw]

Jun 29, 2022 5:50:50 GMT -5 bradshaw said:

"I may have it looked over by a gunsmith. When in doubt, hand it to a professional, am I right?”
----Quick Draw McGraw

*****

“Professional” is term subject to abuse.

A gunsmith with talent, experienced knowledgeable on subject, should be able to sort out the problem. A small deviation in dimension or angle, etc., changes behavior of the whole. If the frame is off in some way or, for instance, the slide stop, or the spring housing has come unstaked, the slide stop could pop up. Holes drilled in the wrong place, cuts made wrong, etc. Job starts with making the frame right, then the parts, and then putting them together.
David Bradshaw

There's a local guy who's pretty good. If all else fails, I'll send it to Huntington.

[gregs]

Taking 320 grit paper glued to a 5 gal pait stir stick and smooth and round the contours of the inside lobe of the slide stop. You can remove tool marks only from the bottom portion of the lobe that is inside the frame and engages the magazine follow. With the gun together, you need .020 clearance from the top of the slide stop arm catch to the bottom rail of the slide. If the Wilson mags are working, fine. Maybe the Act is out of spec, the maxwell to wide ect...

I'll grab my book with the specs tomorrow.

Once the inside lobe is polished, coat it and a couple if cartridges with sharpie to determine where and if possible when it is getting struck. Shortening the plunder tube spring assembly is not the fix. The pressure of the detent is to keep the slide stop in its position. The spring generally is replaced at 5-10k intervals. The re oil spring (16 lb on a got model) at 1500 rds. Shorter slides sooner. My Colt Officer was at 500, 750 I could start having FTRB. The slide speed on shorter than Govt slides kills springs.

PM sent

[Quick Draw McGraw]

I finally got a chance to put 100 factory rounds through my Citadel after replacing the slide-lock/safety plunger spring. I had two lock opens and one FTF. I think the lock opens are a combination of me leaning the pinky of my oversized left hand on the magazine and interfering with its position in the magwell, AND my left thumb occasionally making contact with the slide stop when recoil hits. I noticed no more problems once I kept the left hand clear of the magazine and the the thumb pointed away. Either way, it's a target 1911 and a dang good one for the money. So I'm 100% okay with it as is.