Obviously the mag follower is overriding the slide stop and getting stuck. The problem could lie with either or both parts. Try a few other mags and see if it happens with them as well.

 

DSK should I try another slide stop? I inspected my slide stop and you can see on the bottom where the mag follower contacts it to hold it open theres a slight burr,it can be felt more than seen. Could this be the culprit? This happened with one of the colt factory mags but I can find no damage to either colt mag,it diddn't happen at all with colt mag #2 of either wilson mag. Is there some type of sand paper I can use to remove this small burr from the slide stop? thanks

 

re: no lock

if you have an extended slide stop in place use a short one the extendeds will bounce out of place when firing & as well when i was in the shop i noticed some brands did'nt lock the slide back when mag was empty. thank's tom

 

Suthincomfort its a standard factory sldie stop that came on my gun. The gun is a NRM colt 1991A1. I can feel a bit of a burr on the slide stop but if this were an issue woulden't it have been apparent before now 700 rounds later? Could it be its the magazine as dsk sugessted instead of the slide stop?

 

http://forums.1911forum.com/showthread.php?t=128412
http://forums.1911forum.com/showthre...=1#post1114922

Here's a quick cut & paste for 'failure to lock on empty magazine':

Inadequate slide travel: Is the slide moving back far enough to engage the slide stop? Take out buffer, if present. Recoil spring too strong. Ammo too weak.

Holding down slide stop with thumb. Right or left, if using two hand hold. (Thumb pressure under the slide stop can cause premature slide lock.)

Weak magazine spring not strong enough to lift slide stop. Replace. Stretching the spring will not last.

Too big a 'dimple' on the slide stop, especially combined with an 8 round magazine, can be a factor too.

Follower over-ride: follower moves past slide stop and usually sticks the magazine in the pistol: bad slide stop and/or follower dimensions.

Check slide stop to follower overlap. This is easy. With the slide off and the slide stop in frame - insert and check each magazine. The overlap might be close so that sometimes the follower catches the stop and sometimes not. The problem then: is it the follower or the slide stop -- or both -- at fault?

I crudely measured the wear marks on a couple of followers and got about 0.07 inch [ +/- a bunch ] as the amount the slide stop over rides the follower. I won't argue if someone wants to suggest a different number.

Kuhnhausen gives the dimension of the stud on the slide stop that engages the follower as 0.198 - .002 inch for a .45 ACP.

He gives follower width as 0.472-.006 inch.

The .45 ACP cartridge is .480-.010.

The slide stop might be out of square, which would not allow the tip of the slide stop to protrude far enough into the mag well. Also check that the plunger tube is not loose.


If the follower is the problem, simply bending out the lower leg of GI followers- to make the follower wider - has worked for me. If it binds in the magazine, bend it back. Push down on the follower with the eraser end of a pencil. The follower should move freely the length of the magazine. If it binds, you'll both see and feel it.

Other-than-GI followers will probably have to be replaced. Devel/McCormick style 8 round followers will break if you try to bend them!

 

I can feel a bit of a burr on the slide stop but if this were an issue woulden't it have been apparent before now 700 rounds later?

Guessing, since I don't know the location of the burr -- it might be from the sharp corner on a marginal magazine follower 'digging in' as it rides by. An effect, not a cause.

If 3 mags work but one doesn't.....it's probably the mag.

If it's a Colt magazine with a standard follower, bend the follower - or replace it.

If you have only four magazines ... buy more. Many more.

 

I just took the gun over to my gunsmith and he found the burr on the slide stop I referred to here,it was rather sharp. I also found marks on all four of my mags,both colt's and wilson mags. So he stoned the burr off the slide stop and the colt mag I marked with a bit of paint is locking the slide back now but its hit or miss like it was and getting stuck still. The other three mags don't do this so I have to assume its that one mag where either its spring or follower or both are bad. Could it also be that this one colt mag's feed lips are bad? Should I try another slide stop,or does this make sense being the mag seems to be the culprit here?

 

Since it still hasn't done it with the other magazines I would say the mag is the issue. If the pistol is new you should be able to get Colt to exchange it for you.

 

DSK I'll give colt a call in the morning,but as a side note if the slide stop were out of spec woulden't it have given me this problem from the get go?

 

If the engagement is marginal, it wouldn't take much wear to cause it to start happening. In any case, the magazine is the cheaper fix of the two. If it doesn't solve the problem then you'll know you need to replace the slide stop.

 

DSK I've found the problem its deffenitly the magazine and not the slide stop. I remembered a spare slide stop I had lying around with some other spare 1911 parts and finally found it tonight and installed it on my colt. Bingo same thing with only the one marked colt mag,slide not locking back and magazine stuck in the gun. The other 3 mags a second colt 7 rounder and 2 wilson 47's were fine,so my mind is at ease this is carry gun I diddn't want leave anything to chance I wanted to rule out the problem if I could,and did. So do you agree with my findings based on what I'am describing? These forums really are a great source of infomation I'll say.