Kimber 1911 locking open with not-empty mag

Anyone had this happen on a Kimber or any other 1911? Is it a mag issue or a slide lock issue or something else? Gun is nearly new. Does it maybe half the time firing the first or second round from a fully loaded mag.

Try a Wilson Combat mag.

Roger, will do, thanks!

First time shooting a 1911? Just asking because I’ve seen a lot of guys grip be the issue. They’re riding the slide lock with their palm swell and it pushes up ever so slightly and it will lock the slide back. Since it’s pretty much new the spring and extent might need a little breaking in too.

It's my FIL's. I'll check and see if that might be it. Thanks for the tip.

I've shot 1911s a long time. I have a Colt and an old WW2 Remington Rand that I love to shoot

I thought you had posted about 1911's in the past which is why I asked. Sorry my phone auto corrected me, I meant spring and detent.

Dumb question - is the 7 round or 8 round more likely to be reliable? Or doesn't matter? Does the 8-round stick out past the grip more, or same?

If both of those answers are the same, why do they sell 7 rounders? Just a nod to Mr. John Browning?

This was my first thought also. I shoot 1911's all the time, so I'm not a 1911 newbie. I've had this has happened to me just from me getting lazy. I've also had the opposite happen...Have my thumb too low and activate the mag release on accident.

Sometimes the plunger tube spring and the pin can cause some upward pressure on the slide stop.
I actually had the tip of the pin in the plunger tube have a scrape or scratch across it which would walk the slide stop upwards.

No idea why some prefer 7 rounders.

There are small differences in geometry of mags and also feed ramps.

I tested a bunch of mags long ago. For the last fifteen years or so I have carried the Wilson ETM 8 round mags every day and trust my life to them working correctly.

Tripp Cobra mags and Chip McCormick are others to try, but try the Wilson first.

Cool

This is an Ultra Carry Kimber - do they use regular 1911 mags? WC ETM says they're compatible with Commander, so I assume it's good?

I just looked at Kimber’s webpage for the Ultra Carry and only find the Ultra Carry II. It looks like an officer size frame, which requires a smaller mag. I am not a Kimber guy, so need a Kimber expert to chime in on which size mag the UC 2 needs.

Wilson 47d are the best mags I’ve used in 1911
Down side to them is they will hide deficiencies of the pistol

The Kimber Ultra is Officer size not commander size. I don’t think there is any way of stuffing 8 rounds in an officer size without having the mag stick out of the frame.

Glad you weighed in KR, I just edited mine after looking at Kimber’s webpage.

So any mag that will fit an officer size 1911 should be good?

Grease it, not oil it

Run Wilson Combat magazines

2 biggest issues I’ve saw in 1911’s

I’ve got 1 of of earlier Kimbers (20 plus years old) and I’ve never had an issue w it when doin those 2 things

Call me crazy but this and WC mags

It’s the only firearm I grease

Yes.

Thanks Gus!

Thanks!

This is almost always due to the nose of the bullet bumping the inside lug of the slide stop on feeding. Removing material from the rear corner of the slide stop internal lug and/or shooting more pointed bullets will resolve this issue.

Exactly! Same problem showed up in some early 10mm guns built on 1911 frames and that was the fix, removing some material.

WC all day long. I have one ETM in my collection that randomly will not feed the 4th or 5th cartridge. Since I'm an idiot, I never marked it so it's still floating around the mag pile. I do like them though along with the 47D.

Worked some process of elimination yesterday and it's the mag. Ran down to Ammo Depot and picked up a WC. Now the WC and one of the two Kimber mags work fine. I'll try to figure out how to fix the bad Kimber mag. Looks to me like it has the same problem my Tikka CTR mag had - the spring was bent so the follower tips the round way too far tip-up.

The only reason to keep a defective mag is to have one or two that are known to fail to use to practice malfunction drills. If kept for that purpose, mark it very clearly with a yellow paint marker as a warning and do not mix it up with any other mags that can be used for carry. Otherwise, smash it with a hammer so no one will try to use it and toss it in the trash. Seriously.

On "good" mags that are used for EDC, replacing the mag spring once a year is easily done for routine maintenance, but that is a different issue than starting off defective.

If this is a EDC pistol, buy all Wilson's since you know they work. Quality mags that are 100% reliable are way less costly than losing your life.

For additional consideration
Like a known issue w staccato
1911s do not like to have mags slammed in as it can overtravel and cause mag damage no cause this issue

I'm an engineer and like the challenge of fixing stuff. I'm not the brightest but I like to learn.

That said this will be EDC for my FIL and I'll probably just take the mag back to the place we bought it and see if they'll take it back as defective. I've been buying stuff there for 15 years and I'd even just trade it even for a WC to replace it if they'd go that route since they're about the same price. Long story short...I agree with you.

I have yet to know of a Kimber that was issue free. Won’t own & won’t sell them.