Have any of guy guys seen this before?

[USMCbrat]

I have 2 NTM Colts, both MIV/Series 70’s make in the late 1970’s. One is a Gov Mod and the other is a Gold Cup Nat Match. I alternate range trips with each. There is an issue the comes up from time to time with the GM, where the slides jams at the point where the slide lock is between the slide lock notch and the break down notch. This can happen at anytime during the shooting of a full clip. Now these guns, although made in the 70s only have about 600 rnds through them each. The GC never does this and I tend to shoot it more. Although both have that 70’s series (forget the name) bushing, I am think this is were the problem might be.

Any thoughts?

[wetidlerjr]

I have 2 NTM Colts, both MIV/Series 70’s make in the late 1970’s. One is a Gov Mod and the other is a Gold Cup Nat Match. I alternate range trips with each. There is an issue the comes up from time to time with the GM, where the slides jams at the point where the slide lock is between the slide lock notch and the break down notch. This can happen at anytime during the shooting of a full clip. Now these guns, although made in the 70s only have about 600 rnds through them each. The GC never does this and I tend to shoot it more. Although both have that 70’s series (forget the name) bushing, I am think this is were the problem might be.

Any thoughts?

What makes you think that causes it? Is there something broken or otherwise wrong with the collet bushing on that pistol?
And the 1911 uses magazines, not clips. ;)

[Hunter]

Does it happen with different magazines? How many rounds in the magazine when the failure occurs? What sort of ammunition are you using?
When is the last time you changed the springs? Detail strip and lube? I doubt it is because of the collet bushing.

[USMCbrat]

What makes you think that causes it? Is there something broken or otherwise wrong with the collet bushing on that pistol?
And the 1911 uses magazines, not clips. ;)

When I was in school, I never went to my teachers with a problem without a good guess of what it was and a possible solution. So….to my teachers here…..I can not see anything else that it might be. There is nothing else visible anyway. I looked at the busing closely and can see nothing out of the ordinary. The gun does not so this until it gets a little warm. Anyway, I guess an easy check would be to swap the busing from the GM to the GC too see if it moves or stays put.

And thanks for the terminology education.

[wetidlerjr]

When I was in school, I never went to my teachers with a problem without a good guess of what it was and a possible solution. So….to my teachers here…..I can not see anything else that it might be. There is nothing else visible anyway. I looked at the busing closely and can see nothing out of the ordinary. The gun does not so this until it gets a little warm. Anyway, I guess an easy check would be to swap the busing from the GM to the GC too see if it moves or stays put.And thanks for the terminology education.

Sounds good ! :D

[RickB]

Be careful with a bushing swap. You can damage the bushings removing and reinstalling them on the barrels, and there is a consensus that the main reason for bushing failure was slight mis-machining of slides; if the slide was done wrong, the bushing had stresses put on it that would cause it to fail. If one of your slides is right, and one not so right, you could possibly end up stressing both bushings (or not). It's not like gun parts are delicate, but the S70 bushing system has a fairly bad rep, and "fiddling" with them might make things worse. Better to get a drop-in solid bushing, and focus your experiments on the one gun that is currently giving you problems.

[dakota1911]

My thoughts to the no. 1 post would be the mag or the slide stop. Have had the problem with Kimber, and Para Ord., but not Colt yet. On the other hand I have only owned about 50 "new" Colt 1911s over the years. On the Kimbers it goes away after about a thousand rounds or so and then work O.K. On the Para Ord I played with other slide stops and mags, and got it working with an aftermarket slide stop and mag and traded it off.

[USMCbrat]

Just as a follow up……..

I took my GM to the range yesterday and the problem was worse…it happened with every magazine. Now I have several types of mags on my ammo pouch and being in the anal retentive guy that I am, I was using two identical mags. I took some time to investigate further and found the problem. Both mags are Colt mags with rounded followers. After the last round, one of two things would happen, either the slide would catch on the top round part of the follower causing it to hang with the slide lock in-between the lock notch and the teardown notch OR the slide would keep the follower from tripping the slide lock and the slide would return (to battery …if this is the right term), cocked with no ammo.

I reached in my bag and got 2 more Colt mags but both of these have flat followers. The problem disappeared. When I got home, I played around and confirmed it again. Then I tried to replicate it with my Gold Cup and the GC is not susceptible to this problem.

[Joni Lynn]

I'm glad you got it figured out.