1911, last round jams

[Culwathion]

About once every 50 rounds I get the following failure: on the last round of the magazine (7-round Kimber mags with splits followers and the dimple) the slide locks back leaving the unfired round loose in the chamber area. I can just turn the pistol upside down and the round falls out. It seems to me the magazines are the most likely culprit, but I wonder if it's the follower pushing up the slide stop too soon, or...?

Any informed opinions on this? Thanks in advance.

 

[Snowdog]

I don't suspect the follower/slide stop due to the loose round (the round should be stripped from the magazine by the slide upon chambering). I would put my money on the magazine, specifically the feed lips and or follower.
I guess it could also be the slide stop as well (weak spring) tripping due to recoil, though I doubt it.
However, I'm not a gunsmith... I just own a couple 1911s (one also being a Kimber).



Have you tried other mags with your Kimber?

 

[rskent]

I had a very similar problem a while ago. It turned out not to be a problem with the gun. It was maintenance problem. I had over lubed the gun a few times and gotten a bit of lube in the magazines. It let the rounds jump out of the magazine during recoil. The rounds try to stay still while the gun is recoiling back, voila round jumps out of magazine. A weak magazine spring can have the same result. Going up to an 18 Lb. recoil spring helped a bit early on, but cleaning the magazines inside with a little acetone did the trick. It’s nice to have the old colt running again. I felt a little stupid after that one, but the people on this board really helped me out.

Good luck, I know you will get it sorted out.

Steve

 

[JDGray]

Recoil is jarring the last round loose, engaging the stop. I would try a different mag. I've had my slide lock open with the round just under the feed lips, as forward as you can get it without falling out. Kimber has problems with out of spec stops, look for a copper streak on the nose from bullet contact. I broke my UCII in on low powered target ammo, and never had a failure one, in 600rds. The very first mag of factory ammo, the early slide lock issue started, recoil being the cause.

 

[loadedround]

For all intent and purpose...a bad magazine.

 

[Harvey]

Recoil is jarring the last round loose, engaging the stop. I would try a different mag. I've had my slide lock open with the round just under the feed lips, as forward as you can get it without falling out. Kimber has problems with out of spec stops, look for a copper streak on the nose from bullet contact. I broke my UCII in on low powered target ammo, and never had a failure one, in 600rds. The very first mag of factory ammo, the early slide lock issue started, recoil being the cause.

This is likely to be the problem. The out-of-spec bunion of the slide stop is probably bumping the bullet nose just enough for the last cartridge to simultaneously eject from the mag AND cause the follower to engage the slide stop. This would require some pretty slick timing, all made conducive by recoil and specific spring tensions associated with the last cartridge in the seven-round mag.

I can think of no other explanation. You should press Kimber to provide you with a replacement slide stop, apparently an unofficial but SOP recall issue with Kimber.

Good luck.

 

[Sniper X]

Other than a few other peoples problems with a 1911, and I have 11 of them and have had at least 100 from all makes and types and sizes, I will say this.

99.9 percent of the time, and especially for some reason, with Kimber, or Colt stock magazines, it is the fault of the magazine. Try a 8 rd chip Mc Cormoick mag and see what happens,.....or doesn't.

 

[Oro]

Before blaming the gun or other cast/milled parts, just change the magazine spring.

The last round is the one held by the least tension during the feeding cycle. Like JDGray said, the round is coming loose prematurely. rskent also has a point that lube inside can abet this.

 

[Culwathion]

I should have been more clear, maybe. The pistol is a SA GI-45. But where I live, for some reason, the only magazines I can get through local retailers are Kimbers. I have two and both exhibit the same problem on the last round of the mag (it happens about once per box of ammo, but happens to each mag equally).

Sniper X: Funny you should mention that. A guy at the range lent me his Chip McCormick 8 rd mag and... couldn't replicate the failure.

Anyone have any idea what might make the Kimber mags a little different? I'm willing to take power tools to them to "fix" them if it'll work.

 

[NMGonzo]

Mag problem

I had the same problem on my combat commander.

The Chip McCormick mag fixed it.

 

[Oro]

<....> Just change the springs.

Anyone have any idea what might make the Kimber mags a little different?

Yes, weak springs. Kimber is the major maker least concerned with reliable components. The tubes and follower are fine, just change the springs.

 

[JDGray]

A guy at the range lent me his Chip McCormick 8 rd mag and... couldn't replicate the failure.

Looks like you knew the answer to your problem all along

 

[Art Eatman]

Some people had rational answers, at least...