One mag malfunctions?

Prof Young · December 27, 2018, 06:59 PM

I have a Rock Island 1911 45 auto. I have three mags, all three different brand names. The Mec Gar mag runs just fine until the last shot when the slide does not stay open. The guns works as it should with my other two mags and the slide stays back after last shot. Clearly the Mec Gar mag is some how at fault. Is this something I can diagnose and fix myself?

Talk to me.

Thanks.

Prof Young

mulespurs · December 27, 2018, 07:31 PM

You need to thoroughly need to clean that magazine and put in a new spring.

The reason that the slide is not locking back is a lack of magazine spring oompf
in my experience.

Or the body and follower of the mag is dirty or gummy and slowing it down.

dahermit · December 27, 2018, 09:17 PM

Quote:

The reason that the slide is not locking back is a lack of magazine spring oompf...

Not necessarily.

Place the malfunctioning magazine in the gun. Lock the slide back. Look down through the ejection port and observe how on some (not all brands and style of followers), magazines there is a little "step" in the magazine follower that engages the slide stop. That is what is supposed to actuate the slide stop after the last shot. If it does not, it may need to be bent slightly upward. After bending it upward, try the magazine function by test firing it again. It is something to try before swapping out the magazine spring.

In any event, if you study how the magazine follower engages the slide stop, you should be able to figure out the cause of the failure to lock back as it should...it is not rocket science.

wv109323 · December 27, 2018, 10:34 PM

Put the faulty mag in the pistol and pull the slide back. Does it stay?
Take one of the working magazines and observe how the mag follower lifts the slide stop when the slide is pulled back.
Compare the working mags with the faulty.
You may be able to bend the follower to activate the slide stop.

dahermit · December 28, 2018, 10:15 AM

Quote:

Put the faulty mag in the pistol and pull the slide back. Does it stay?
Take one of the working magazines and observe how the mag follower lifts the slide stop when the slide is pulled back.
Compare the working mags with the faulty.
You may be able to bend the follower to activate the slide stop.

Did you read the post before yours?

**4V50 Gary** · December 28, 2018, 10:26 AM

I'd compare the followers.
If they're the same, the spring may not be strong enough to push the follower fast enough to engage the slide stop.

A local cop had trouble with his "big name" magazines. Wilson's. They jammed. He was told to buy Colt or USGI.

T. O'Heir · December 28, 2018, 02:06 PM

Easier and less fuss to replace that mag than fiddle with it. I might consider sending it back to Mec Gar. You should not have to fix the stuff you buy new.

dahermit · December 28, 2018, 02:57 PM

Quote:

Easier and less fuss to replace that mag than fiddle with it.

That is good advice if one is so inept that they cannot operate needle-nose pliers. Note however, not all followers have that little metal tab that G.I. magazine followers had/have...some are not adjustable.

Inasmuch as he posted,

Quote:

Is this something I can diagnose and fix myself?

It is not likely he wants to send the mag back to MecGar as a first step, he appears to want to do a little self-help.

Prof Young · December 29, 2018, 02:22 PM

Hey, good advice all around. I'll have a go at it get back to you.
This is why I like this forum.

Life is good.

Prof Young

BillW · December 29, 2018, 09:40 PM

Not to hijack the thread, but I recently purchased a Colt Light Weight Commander in 38 Super that came with two magazines. I also purchased four aftermarket mags. One of the original mags (with a metal mag follower) and all four aftermarket mags work perfectly. One of the Colt mags (with an orange plastic mag follower) locks the slide open with one round left in the magazine. Dropping the slide feeds the last round and locks the slide back after firing the last round.

Any suggestions? I have looked for replacement mag followers unsuccessfully. I tried using a Wilson 45 follower but it would not fit into the magazine.

Prof Young · December 29, 2018, 09:47 PM

Okay, I've inspected all my mags, looked at all of them in the gun, cleaned the gun thoroughly, and have learned a bit. Let me make sure I'm straight on this . . . after the last round, the mag follower is supposed to engage the slide lock lever and push it up into the lock position. Right?

Talk to me.

Thanks.

Life is good.
Prof Young

dahermit · December 29, 2018, 11:28 PM

Quote:

Let me make sure I'm straight on this . . . after the last round, the mag follower is supposed to engage the slide lock lever and push it up into the lock position. Right?

Right.

dahermit · December 29, 2018, 11:32 PM

Quote:

Originally Posted by BillW

Not to hijack the thread, but I recently purchased a Colt Light Weight Commander in 38 Super that came with two magazines. I also purchased four aftermarket mags. One of the original mags (with a metal mag follower) and all four aftermarket mags work perfectly. One of the Colt mags (with an orange plastic mag follower) locks the slide open with one round left in the magazine. Dropping the slide feeds the last round and locks the slide back after firing the last round.

Any suggestions? I have looked for replacement mag followers unsuccessfully. I tried using a Wilson 45 follower but it would not fit into the magazine.

Have you tried here? https://shopwilsoncombat.com/Spring_...o/500SFK38-10/

It is not surprising that the .45 ACP magazine follower would not fit in a .38 Super magazine tube. The .38 Super magazine tube has a couple of "grooves" in it that a .45 ACP mag tube does not.

You may want to post your problem with the slide locking back before the magazine is empty here: https://forums.1911forum.com/

RickB · December 30, 2018, 11:55 AM

I've never seen a Colt "factory" mag (usually Metalform or Check-Mate, Colt hasn't made mags for years) with a plastic follower?

Every manufacturer has their own ideas regarding magazine design, and it is often the case that a given manufacturer's mag might not be compatible with a given gun.

I was looking at my 10mm mags, from three different makers, and the only thing the same across all three is the external "envelope"; the feedlips and followers are unique to each maker. Some swear by .45 mags in their 10mm!
They all work in my gun, but it would come as no surprise if they didn't all work in every gun.

dahermit · December 30, 2018, 01:49 PM

Quote:

I was looking at my 10mm mags, from three different makers, and the only thing the same across all three is the external "envelope"; the feedlips and followers are unique to each maker.

In regard to the 1911 .45 ACP, it is not a matter of different manufacturers using a different feed lips, it is that there are three distinct styles of feed lips: The G.I. with straight lips for feeding hard ball, the "wadcutter" feed lips and the "hybrid" style.

dahermit · December 30, 2018, 01:58 PM

Quote:

I've never seen a Colt "factory" mag (usually Metalform or Check-Mate, Colt hasn't made mags for years) with a plastic follower?

Colt may not make the magazines they supply with their guns, but the have no qualms about stamping them with the Colt logo.

December 27, 2018, 06:59 PM	#1
Prof Young Senior Member Join Date: August 21, 2007 Location: Illinois - down state Posts: 2,404	One mag malfunctions? I have a Rock Island 1911 45 auto. I have three mags, all three different brand names. The Mec Gar mag runs just fine until the last shot when the slide does not stay open. The guns works as it should with my other two mags and the slide stays back after last shot. Clearly the Mec Gar mag is some how at fault. Is this something I can diagnose and fix myself? Talk to me. Thanks. Prof Young

December 27, 2018, 07:31 PM	#2
mulespurs Senior Member Join Date: February 26, 2012 Posts: 115	Just my experience You need to thoroughly need to clean that magazine and put in a new spring. The reason that the slide is not locking back is a lack of magazine spring oompf in my experience. Or the body and follower of the mag is dirty or gummy and slowing it down.

December 28, 2018, 10:26 AM	#6
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 21,838	I'd compare the followers. If they're the same, the spring may not be strong enough to push the follower fast enough to engage the slide stop. A local cop had trouble with his "big name" magazines. Wilson's. They jammed. He was told to buy Colt or USGI. __________________ Vigilantibus et non dormientibus jura subveniunt. *Molon Labe!*

December 28, 2018, 02:06 PM	#7
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	Easier and less fuss to replace that mag than fiddle with it. I might consider sending it back to Mec Gar. You should not have to fix the stuff you buy new. __________________ Spelling and grammar count!

December 29, 2018, 02:22 PM	#9
Prof Young Senior Member Join Date: August 21, 2007 Location: Illinois - down state Posts: 2,404	thanks you so much! Hey, good advice all around. I'll have a go at it get back to you. This is why I like this forum. Life is good. Prof Young

December 27, 2018, 10:34 PM	#4
wv109323 Member Join Date: December 1, 2012 Posts: 18	Put the faulty mag in the pistol and pull the slide back. Does it stay? Take one of the working magazines and observe how the mag follower lifts the slide stop when the slide is pulled back. Compare the working mags with the faulty. You may be able to bend the follower to activate the slide stop.

December 29, 2018, 09:40 PM	#10
BillW Junior Member Join Date: March 21, 2000 Posts: 14	Not to hijack the thread, but I recently purchased a Colt Light Weight Commander in 38 Super that came with two magazines. I also purchased four aftermarket mags. One of the original mags (with a metal mag follower) and all four aftermarket mags work perfectly. One of the Colt mags (with an orange plastic mag follower) locks the slide open with one round left in the magazine. Dropping the slide feeds the last round and locks the slide back after firing the last round. Any suggestions? I have looked for replacement mag followers unsuccessfully. I tried using a Wilson 45 follower but it would not fit into the magazine.

December 29, 2018, 09:47 PM	#11
Prof Young Senior Member Join Date: August 21, 2007 Location: Illinois - down state Posts: 2,404	Am closer to fix but . . . Okay, I've inspected all my mags, looked at all of them in the gun, cleaned the gun thoroughly, and have learned a bit. Let me make sure I'm straight on this . . . after the last round, the mag follower is supposed to engage the slide lock lever and push it up into the lock position. Right? Talk to me. Thanks. Life is good. Prof Young

December 30, 2018, 11:55 AM	#14
RickB Senior Member Join Date: March 1, 2000 Location: Boise, ID Posts: 8,518	I've never seen a Colt "factory" mag (usually Metalform or Check-Mate, Colt hasn't made mags for years) with a plastic follower? Every manufacturer has their own ideas regarding magazine design, and it is often the case that a given manufacturer's mag might not be compatible with a given gun. I was looking at my 10mm mags, from three different makers, and the only thing the same across all three is the external "envelope"; the feedlips and followers are unique to each maker. Some swear by .45 mags in their 10mm! They all work in my gun, but it would come as no surprise if they didn't all work in every gun. __________________ Runs off at the mouth about anything 1911 related on this site and half the time is flat out wrong.