Colt 1911 Jams with only FMJ ammo

[E_Evans]

I recently inherited a Colt Combat Commander series 80 1911. On my first trip to the range I immediately incountered problems when using standard 230 grain FMJ ammunition, which in my immediate area are the only .45acp target rounds readily available and which I bought a bunch of, silly me. Anyway, after firing one round, no matter how many rounds are left in the magazine, the slide locks open like it should when there's an empty magazine. However, I had some Semi-wadcutter hand loads that where made by the previous owner of the gun, my grandfather, these rounds worked flawlessly, all 100 or so of them that I had. When I again tried the the Jacketed ammo, immediately I had the same problem. Then I tried some Silver Tipped Hollow Points (185gr) that I had bought for carry, and these two worked flawlessly.

Knowing that gun sat in the closet for 10years, I field stripped it and cleaned it thoroughly, then I took it back to range and had the exact same problem with the jacketed ammo, the STHP's worked fine again.

My grandfather was something of a gunsmith, and I know this gun has had work done to it, the trigger pull is perfect, and the extractor has evidence of either being filed, or simply worn. Whatever else he might have done to it no one knows

I love this gun, aside from wanting to carry it I also would like to get more use out of it at the range. It's not a big problem but it is a slight hassle to get wadcutters around here, and I'm not in a good place to load my own.

Does anyone know why I would having problems with only the FMJ ammo? Could it be a magazine problem? Extractor? etc... Could it have something to do with the overall length of the ammo, being that the shorter stuff works fine? Any info is appreciated, like I said, it's no biggy, but I like my things to work the way they're supposed to.

Thanks - Eric

[nemesis]

It sounds like your troublesome FMJ rounds are just big enough to nudge the slide stop as they are being stripped from the magazine. Lock the slide back and see if the rounds are touching the slide stop. You may have to remove a small amount of material.

[1911Tuner]

Hi Evans,

In addition to the most probable cause given by nemesis...since the gun has laid idle for 10 years, there's the real possibility that the plunger spring has taken a set, and not offering enough resistance against the slidestop to prevent its engagement under the inertial effects of recoil. Also a smaller possibility that slidestop's rear face is incorrect. One way to tell if it's inertia induced is to fire the gun with an extremely loose grip. If the problem improves or goes away...that may be your bug. A new recoil spring may help, but the real problem is with either the plunger spring or the slidestop itself. An extended (heavier) slidestop aggravates the effects of inertia, and makes the malfunction more likely.

When the stop engages, does it engage into the notch to full depth, or just on the corner?

[E_Evans]

1911Tuner

When this happens with the FMJ's the stop is in all the way.

Thank you both for your help.

[1911Tuner]

1911Tuner

When this happens with the FMJ's the stop is in all the way.

Thank you both for your help.

Sounds like nemesis probably nailed it then.

Slide off the frame...slidestop in normal position...use a strong light as you slide a loaded mag into place slowly and watch for the point of contact. It won't take much, so look closely. It may take several tries...just make sure the stop is full down, as it would be
if the gun was completely assembled.

Use a fine-cut mill file to lightly relieve the stop's lug at the point of contact. Don't overdo it. Just a few thousandths inch of clearance is all it takes.

[E_Evans]

Thank you for your help.

I'll probably get to the range this weekend and I'll let you know how I make out. I'm glad I found this forum, the 1911 is a great handgun, my grandfather got me addicted to them early.

Thanks again, - Eric