Tuning a 1911?

[hlee]

I have a 1911 that is having an issue where about once every couple of mags, the slide stop engages. My research suggests this is an issue where the cartridges in the mag can hit the slide stop and holds the action open. The remedy seems to be- if you see copper on the slide stop- to file the slide stop enough to prevent the interference. Ok, cool. Here’s a pic of the failure. Note, I did not lock the action open to take the pic. The action locked open on the previous round, and I did not disturb the round in the mag to take the pic. What you see is what I saw. The mags are 8 round stainless Wilson Combat mags. Overall, the gun has about 1000 or so rounds on it, split across 8 mags, so the mags are pretty fresh…

Other than guess and check on filing down the slide stop, anything else I should be looking at? This is a fun gun, so reliability is only a concern in as much as guns that run are more fun that guns that don’t. Thanks.

 

[John?]

An out of spec mag catch can cause that too - mag riding too high in the mag well.

I have an old Para double stack 45 that exhibited that problem on the regular. Modifying the slide stop cured it.

 

[wvfarrier]

^^^ this would be my first suggestion

 

[Old Man with Gun]

Also make sure your grip isn't contacting the mag catch.

 

[gigamortis]

Seems to me that when a slide lock lever locks the slide back inadvertently, the top round of the magazine should still be entirely in the magazine.

Your pic shows a cartridge that has started the feed cycle. I'd like to know how that occurred.

 

[hlee]

Seems to me that when a slide lock lever locks the slide back inadvertently, the top round of the magazine should still be entirely in the magazine.

Your pic shows a cartridge that has started the feed cycle. I'd like to know how that occurred.

So would I. It seems that recoil is causing it. Maybe the round above is dragging the lower round forward a bit when it loads. Note that it is the last round in the mag, so it has the least spring tension on it. But, it is not always the last round. I’ve had it happen as many as 3 consecutive rounds.

I’m going to start marking mags to see if it tracks to one or more of them. I really don’t want to start randomly bending on feed lips.

 

[hlee]

Also make sure your grip isn't contacting the mag catch.

Support hand position…

You’ll have to forgive that I only have 2 hands, and removed my firing hand so that I could take the pic…

 

[ECK]

Take the slide off, re-insert the slide stop. Then watch as you insert a mag to see if anything is pushing up on the slide stop.

Last thing, make sure your support hand is not inadvertently engaging the slide stop under recoil.

 

[6brshooter]

I build 1911s, so ill try to help. What brand pistol, ammo, and which wilson mag(47d or etm)? Has this problem always happened or is it a new issue? That looks like last rd, so possible inertia feed. If this has always happened since you owned it, it is possible that it has a 45 slide stop with an oversized tab or it is a 9mm slide stop that ended up in that pistol(bullet noses coming up mag tube push slide stop). Also, if this occurred since new, it could be the relief in back of slide stop that detent plunger bears on is shallow and not allowing it to stay down until actual follower makes positive contact. If this is just started happening to an otherwise perfect running 1911, could be dirt/rust inside plunger tube that is keeping slide stop detent from working 100%, or that plunger spring is broke/weak.

Soap box time, if those are 47d wilson mags, convert to 7rd guts. Those are notorious for causing last rd feed issues after a little bit of use, especially if kept loaded 100%. The wilson etm mags and cobra tripp ARE the 1911 mags that others are judged by.

 

[gigamortis]

I build 1911s, so ill try to help. What brand pistol, ammo, and which wilson mag(47d or etm)? Has this problem always happened or is it a new issue? That looks like last rd, so possible inertia feed. If this has always happened since you owned it, it is possible that it has a 45 slide stop with an oversized tab or it is a 9mm slide stop that ended up in that pistol(bullet noses coming up mag tube push slide stop). Also, if this occurred since new, it could be the relief in back of slide stop that detent plunger bears on is shallow and not allowing it to stay down until actual follower makes positive contact. If this is just started happening to an otherwise perfect running 1911, could be dirt/rust inside plunger tube that is keeping slide stop detent from working 100%, or that plunger spring is broke/weak.

Soap box time, if those are 47d wilson mags, convert to 7rd guts. Those are notorious for causing last rd feed issues after a little bit of use, especially if kept loaded 100%. The wilson etm mags and cobra tripp ARE the 1911 mags that others are judged by.

+1 for the newer Wilson ETM magazines. They have replaced my Tripp Cobra mags. The Wilson ETMs have a little bit shorter feed lip which feeds some of my shorter OAL loadings more reliably.