1911 mag issue

cptmclark · December 7, 2013, 11:13 PM

Last time out both 45s had same new issue. The last round of both mags jammed with round chambered but bolt not closed due to extractor following, rather than capturing the rim . In other words the extractor hook was behind the rim preventing slide from going into battery. Last round only.
Ill not guess but what is common cause of this jam?
Thanks

Scorch · December 8, 2013, 02:35 AM

The cause is the magazine feed lips allowing the round to jump ahead of the slide instead of being pushed forward by the slide. Whether the rounds are defective or the feed lips are worn is for you to determine.

polyphemus · December 8, 2013, 07:51 AM

The common cause here seeing as your magazines have worked so far would
be weak springs,I would replace them with extra power ones.

**4V50 Gary** · December 8, 2013, 08:55 AM

Does it do the same thing with Colt or GI magazines? If not, it's your magazines. Compare the lips and the follower with those of the Colt/GI.

cptmclark · December 8, 2013, 09:39 AM

One mag is an "ACT-MAG" and the other Wilson Combat. I've had several both kinds with good success in the past. Both of these have worked well in the past. The ACT MAG is in a Citadel compact that has worked flawlessly for its short life which is no more than 200 rounds. Just getting broken in. The other, the Wilson, is in a full size carry gun and that mag has stayed loaded for a long time. I shoot it empty from time to time but it gets reloaded right away.

I hear that some types of spring metals don't get weak from staying compressed, but I don't know which is which.

Interesting that it is only the last round of the mag that is the offender. That lends credence to the weak spring idea. The springs "feel" tight, as the last round is difficult to load. With the mag empty, the import feels tighter with thumb pressure on the follower, whatever that might be worth.

I had wondered if a recoil spring being too tight or two weak might cause a cycle to quick or too short, but I can't see the logic quite.

One recoil spring is whatever factory stiff spring the sort barrel requires, and the one in the full size pistol is a 22 pounder. I bought that a while back when shooting +P in a Gold Cup.

I don't have a good Colt mag anymore so can't make a good comparison there.

Thanks for the ideas. I appreciate you guys.

HiBC · December 8, 2013, 09:53 AM

I'm not a 1911 ghuru,but if the extractor is not messed up,think about the slide moving forward and stripping the round.If the bolt face is in contact with the round,the round cannot get aheadof the extractor.

Hmmm,

But now imagine that round is only held in position by the mag spring against the feed lips.Think of the rounds inertia,and the gun literally recoiling out from under it.Then the round has moved up and forward while the slide is still back.
The extractor will be what drives the round forward

Options:

New mag spring,Wolfe +10%

Do you have a dimple on the follower? That is what it is for,last round retention.No dimple? Look at other mags.

If you are loading hot,or if your recoil spring is fatigued or softball,your slide may be smacking back harshly,pulling the gun out from under the round.

A very soft ,relaxed hold can contribute.Hold at least a very firm handshake.

One more idea,the slide stop.The follower lifts the slide stop as the last round feeds.That means the slide stop and the follower engage on the last round.Given,everything on a 1911 requires fitting,it might be a left thumb contacting an extended slide stop is blocking the follower rise.

polyphemus · December 8, 2013, 09:55 AM

The recoil spring function is to return the slide to battery.A 22Lb spring sounds
too stiff and could be interfering with the normal cycle especially on the last
round when there's least magazine spring pressure.

HiBC · December 8, 2013, 10:09 AM

Agreed on the 22 lb spring.Try a stock rate replacement,16 or 18 lbs,I believe.

Those heavy springs beat the gun harder going forward.Think about your slide stop and barrel underlug

cptmclark · December 8, 2013, 10:09 AM

Slow cycling by hand watching the pickup looks perfect. Of course there is no recoil. Since both of these pistols did the same thing, the same day within a few minutes of each other, the operator error idea looks promising. Altought I'd hate to think that in serious use I'd have to use a textbook hold to avoid a jam.

The short gun mag spring is stout enough that it's challenging to load the first round. No so on the Wilson eight rounder. I will change the spring on that one for sure.

Regarding the slide spring, both "feel" stiffer than a normal 1911 slide. Of course the smaller one needs a stiffer spring and like I said I deliberately put a stiffer spring on the full size unit. Neither spring has more than 500 rounds or two years on it yet. Of course changeing springs for good measure is an inexpensive thing to do.

Not sure I want a gun I have to hold perfectly for it to function. I know about extreme limp wristing and that's not what I'm talking about.

cptmclark · December 8, 2013, 10:23 AM

The heavier spring came from a talk with a Colt GS, asked about the Gold Cup and whether there was anything unique about it that would prevent using +P ammo in it. He suggested the heaving spring. This gun is not a gold cup however, and I don't think they are stronger or weaker anyway.
I'll replace the spring in the 5 inch. and the mag spring as well.

That leaves the newish 3 1/2 inch pistol. It is box stock.
Of course I don't remember it doing this before. These were the last rounds of the day and I didn't give the pistols a chance to redeem themselves. Of course, one is too many.

polyphemus · December 8, 2013, 11:49 AM

Quote:

the operator error idea looks promising.

Not to me.

polyphemus · December 8, 2013, 12:01 PM

While you have it stripped pull the extractor out and carefully check it.If you have a loupe or some kind of magny glass look at the hook and the plunger recess for nicks or other damage,long shot but I've seen it.

James K · December 9, 2013, 09:19 PM

I will second HiBC's thought about the little "bump" or "pimple" in the magazine follower. That "bump" looks like it is not important but it is.

Jim

cptmclark · December 9, 2013, 10:06 PM

The older Wilson mag has a hump down the center of the follower. The other one does not, Neither did my Colt mags. I'm glad to know it's a good feature.

James K · December 10, 2013, 02:36 PM

I don't think the "hump down the center" is what I meant. The follower should have a "pimple" or small "teat" in the follower. Without that, the slide will bump the last round and cause it to jump forward ahead of the extractor. The "teat" slows the round just enough that it will not jump forward but will rise up under the extractor.

Some magazine gurus though the "teat" was useless and interfered with "smooth" feeding, so some makers left it out, and the result is what you have experienced.

Incidentally, those curved followers are useless nonsense. Any high school geometry student knows that an arc touches a line at only one point, so the only difference between a curved follower and a flat follower is that the makers charge more for the curve.

Jim

RickB · December 11, 2013, 04:49 PM

A 22# recoil spring is waaaay too heavy. As noted above, it's more of a "feed spring", and most guns will feed reliably with a 12# spring, so no reason to go way overboard in the other direction. I'd expect a replacement recoil spring (no heavier than 16#) might solve the problem, but if you don't associate the issues with a change in recoil spring, and the gun was running right previously, mag springs is probably the issue.
Check the top-rear of the ACT-Mag for cracks. All of mine cracked, and while it never became a functional issue, I didn't continue using them after the cracks appeared. If the crack got large enough that it allowed the feedlips to splay out, early release of the cartridge could cause it to get out ahead of the extractor.

December 7, 2013, 11:13 PM	#1
cptmclark Senior Member Join Date: November 22, 2004 Location: Indiana Posts: 432	1911 mag issue Last time out both 45s had same new issue. The last round of both mags jammed with round chambered but bolt not closed due to extractor following, rather than capturing the rim . In other words the extractor hook was behind the rim preventing slide from going into battery. Last round only. Ill not guess but what is common cause of this jam? Thanks

December 8, 2013, 02:35 AM	#2
Scorch Senior Member Join Date: February 13, 2006 Location: Washington state Posts: 15,248	The cause is the magazine feed lips allowing the round to jump ahead of the slide instead of being pushed forward by the slide. Whether the rounds are defective or the feed lips are worn is for you to determine. __________________ Never try to educate someone who resists knowledge at all costs. But what do I know? Summit Arms Services

December 8, 2013, 08:55 AM	#4
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 21,841	Does it do the same thing with Colt or GI magazines? If not, it's your magazines. Compare the lips and the follower with those of the Colt/GI. __________________ Vigilantibus et non dormientibus jura subveniunt. *Molon Labe!*

December 8, 2013, 09:53 AM	#6
HiBC Senior Member Join Date: November 13, 2006 Posts: 8,288	I'm not a 1911 ghuru,but if the extractor is not messed up,think about the slide moving forward and stripping the round.If the bolt face is in contact with the round,the round cannot get aheadof the extractor. Hmmm, But now imagine that round is only held in position by the mag spring against the feed lips.Think of the rounds inertia,and the gun literally recoiling out from under it.Then the round has moved up and forward while the slide is still back. The extractor will be what drives the round forward Options: New mag spring,Wolfe +10% Do you have a dimple on the follower? That is what it is for,last round retention.No dimple? Look at other mags. If you are loading hot,or if your recoil spring is fatigued or softball,your slide may be smacking back harshly,pulling the gun out from under the round. A very soft ,relaxed hold can contribute.Hold at least a very firm handshake. One more idea,the slide stop.The follower lifts the slide stop as the last round feeds.That means the slide stop and the follower engage on the last round.Given,everything on a 1911 requires fitting,it might be a left thumb contacting an extended slide stop is blocking the follower rise. Last edited by HiBC; December 8, 2013 at 10:01 AM.

December 8, 2013, 07:51 AM	#3
polyphemus Senior Member Join Date: June 24, 2012 Posts: 1,055	The common cause here seeing as your magazines have worked so far would be weak springs,I would replace them with extra power ones.

December 8, 2013, 09:39 AM	#5
cptmclark Senior Member Join Date: November 22, 2004 Location: Indiana Posts: 432	One mag is an "ACT-MAG" and the other Wilson Combat. I've had several both kinds with good success in the past. Both of these have worked well in the past. The ACT MAG is in a Citadel compact that has worked flawlessly for its short life which is no more than 200 rounds. Just getting broken in. The other, the Wilson, is in a full size carry gun and that mag has stayed loaded for a long time. I shoot it empty from time to time but it gets reloaded right away. I hear that some types of spring metals don't get weak from staying compressed, but I don't know which is which. Interesting that it is only the last round of the mag that is the offender. That lends credence to the weak spring idea. The springs "feel" tight, as the last round is difficult to load. With the mag empty, the import feels tighter with thumb pressure on the follower, whatever that might be worth. I had wondered if a recoil spring being too tight or two weak might cause a cycle to quick or too short, but I can't see the logic quite. One recoil spring is whatever factory stiff spring the sort barrel requires, and the one in the full size pistol is a 22 pounder. I bought that a while back when shooting +P in a Gold Cup. I don't have a good Colt mag anymore so can't make a good comparison there. Thanks for the ideas. I appreciate you guys.

December 8, 2013, 09:55 AM	#7
polyphemus Senior Member Join Date: June 24, 2012 Posts: 1,055	The recoil spring function is to return the slide to battery.A 22Lb spring sounds too stiff and could be interfering with the normal cycle especially on the last round when there's least magazine spring pressure.

December 8, 2013, 10:09 AM	#8
HiBC Senior Member Join Date: November 13, 2006 Posts: 8,288	Agreed on the 22 lb spring.Try a stock rate replacement,16 or 18 lbs,I believe. Those heavy springs beat the gun harder going forward.Think about your slide stop and barrel underlug

December 8, 2013, 10:23 AM	#10
cptmclark Senior Member Join Date: November 22, 2004 Location: Indiana Posts: 432	The heavier spring came from a talk with a Colt GS, asked about the Gold Cup and whether there was anything unique about it that would prevent using +P ammo in it. He suggested the heaving spring. This gun is not a gold cup however, and I don't think they are stronger or weaker anyway. I'll replace the spring in the 5 inch. and the mag spring as well. That leaves the newish 3 1/2 inch pistol. It is box stock. Of course I don't remember it doing this before. These were the last rounds of the day and I didn't give the pistols a chance to redeem themselves. Of course, one is too many.

December 8, 2013, 12:01 PM	#12
polyphemus Senior Member Join Date: June 24, 2012 Posts: 1,055	While you have it stripped pull the extractor out and carefully check it.If you have a loupe or some kind of magny glass look at the hook and the plunger recess for nicks or other damage,long shot but I've seen it.

December 9, 2013, 09:19 PM	#13
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	I will second HiBC's thought about the little "bump" or "pimple" in the magazine follower. That "bump" looks like it is not important but it is. Jim

December 9, 2013, 10:06 PM	#14
cptmclark Senior Member Join Date: November 22, 2004 Location: Indiana Posts: 432	The older Wilson mag has a hump down the center of the follower. The other one does not, Neither did my Colt mags. I'm glad to know it's a good feature.

December 10, 2013, 02:36 PM	#15
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	I don't think the "hump down the center" is what I meant. The follower should have a "pimple" or small "teat" in the follower. Without that, the slide will bump the last round and cause it to jump forward ahead of the extractor. The "teat" slows the round just enough that it will not jump forward but will rise up under the extractor. Some magazine gurus though the "teat" was useless and interfered with "smooth" feeding, so some makers left it out, and the result is what you have experienced. Incidentally, those curved followers are useless nonsense. Any high school geometry student knows that an arc touches a line at only one point, so the only difference between a curved follower and a flat follower is that the makers charge more for the curve. Jim

December 11, 2013, 04:49 PM	#16
RickB Senior Member Join Date: March 1, 2000 Location: Boise, ID Posts: 8,518	A 22# recoil spring is waaaay too heavy. As noted above, it's more of a "feed spring", and most guns will feed reliably with a 12# spring, so no reason to go way overboard in the other direction. I'd expect a replacement recoil spring (no heavier than 16#) might solve the problem, but if you don't associate the issues with a change in recoil spring, and the gun was running right previously, mag springs is probably the issue. Check the top-rear of the ACT-Mag for cracks. All of mine cracked, and while it never became a functional issue, I didn't continue using them after the cracks appeared. If the crack got large enough that it allowed the feedlips to splay out, early release of the cartridge could cause it to get out ahead of the extractor.