A Magazine Malfunction (Revisited)

[1911Tuner]

Mornin'! I did this one a while back, but it's been buried for so long...and the question comes up a lot...so I figured that it might be a good time to
re-post it, and copy the link into the sticky Consoliditated Clinic.

The issue is a malfunction that leaves the last round loose on top of the magazine with the slide locked. Hope this helps somebody along life's way.
________________________________

Inertia! Just no way to get around Newton's Laws regarding motion.
Remember the old trick of jerking a tablecloth out from under a table setting? This is the principle at work here.

We have a round in the chamber and one round in the magazine.

Bang! The slide starts to move as the pistol torques up and back. The slide holds the last round slightly below the feeding position until it moves far enough to uncover it. Just as the magazine spring is struggling to move the round into position, the round is in a sort of "Limbo" while the pistol continues to move backward in recoil. The round obeys Newton, and stands still while the gun is moving away from it.

The magazine spring catches up, and gets the round up and into the underside of the feed lips, but because the pistol pulled backward away from it (Even though the pressure from the slide drags the round backward in the magazine)...it settles down forward of the feeding position. At this point, if the magazine spring is strong enough to keep it there, the slide pushes it ahead of the extractor. The pistol either fails to go to battery with the round fully chambered, and the front of the extractor rammed against the back of the rim. Extractor breakage is an eventuality.

If the spring isn't strong enough, the round is forward of optimum feeding position just as the slide smacks the impact surface in the frame, and triggers a second recoil impulse. The gun makes a short, hard jerk upward and backward...and the round is in limbo once more because the mass of the round has caused the magazine spring to compress slightly. The round...already too far forward in the magazine...jumps the follower, and is free of the magazine. The follower pushes the slidestop up as the slide moves forward, and the slide locks. If the magazine spring is weak enough, the next to last round will be ejected from the magazine, and the last round feeds. Ever found live ammo among your brass? Heeere's yer sign!

The problem is two-fold. One is the spring that has fewer coils to make room for the extra round. There is ample tension to feed until it gets to the last round...and tension is at a mimimum...but sometimes it can happen before the last round. Upping the spring rate helps, but doesn't address the other issue.

The other part of the problem is the smooth follower. Browning knew how
inertia would affect things, and he put a small dimple on the top of the magazine follower. The dimple's function is two-fold. It adds a small amount of height to the follower in order to give it a "Leg Up"...and it stops the forward movement of the round. More accurately, it keeps the pistol from moving out from under the round in recoil. In this function, it's basically a back-up for the spring as it fatigues, and provides a better opportunity for the round to stay in position to be stripped from the magazine by the slide instead of being pushed ahead of it...or... in the extreme cases, escaping from the magazine completely.

John Moses designed a 7-round magazine and he put a dimple on the follower for very good reasons. Whenever we try to change things in order to "improve" the gun...we very often cause problems. There just ain't no such thing as a free lunch, I'm 'fraid.

Cheers all!

Tuner

 

[Old Fuff]

There you are, bringing up that “little dimple†business. All of the “New School†folks know that’s nonsense. It was only supposed to be some kind of cosmetic thing, and clearly isn’t necessary. That’s why they use 8-round magazines with rounded followers.

On the other hand, those who are more interested in the pistol’s history rather then how many lines of checkering should be on the forestrap, should take note of the following, which is taken from a list of changes and/or improvements that were made to a prototype pistol that was tested by the Army in late 1910.

“12. A raised dimple was formed in the middle of the magazine follower to assist the last cartridge as it left the magazine.†(Report: November 1910 Pistol Trials, conducted on November 7, 1910).

So it would seem that Tuner is right again, and that magazines with rounded or altered followers without that dimple are a mistake. That dimple didn’t show up until the end of the pistol’s development, but Browning put it there for a reason - and a good one - because earlier trials had shown that there was a problem that need correcting.

So from now on Tuner can prove that he isn’t just blowing smoke.

 

[1911Tuner]

Dang Dimple

LOL Fuff...You're in rare form this mornin' aintcha?

Another point on that dimple...Its location closely coincides with the magazine's release point...so usin' a punch to put one on a follower that doesn't have one won't work unless it's in the right place.

The reason that I re-did the thread is because here lately, there seems to have been a rash of problems...on the forums and here in the 'hood. Recently, I tweaked up a top end for a former forum member, and he wrote back last night that every one of his magazines produced a last round
failure to feed. The slide was locked, and the last round was layin' loose
on top of the magazine. All were nearly new Wilson 47Ds. Clearly, there is a trend there.

Cheers! Fall is in the air, and I'm a happy camper...even though October was delayed until November this year.

 

[1911WB]

Mag issues

John- thanks for the great explanation as always. While I don't currently have the problem you describe so eloquently, I'm sure I will eventually! Therefore, I'm prompted to ask which mags in current prduction have the dimple? Also, I think you've said in the past that you don't think Tripp Cobra mags are a good way to go- any elaboration on that? WB

 

[1911Tuner]

Dang Dimple...

Howdy WB,

About any traditional, 7-round magazine with a flat follower will have it. Factory Colt...Springfield GI Mil-Spec...Some Kimbers, etc. High-Standard
contract magazines that Midway sometimes offers are ones that have it, though the magazines aren't the best quality as far as the tubes and weld strength on the base plates go...they seem to hold up pretty well. They still need better springs, though.

Most of those mentioned above are made under contract by Metalform,
and you can order direct from Metalform. A bulk order will net a huge discount per magazine...40 or more.

The problem with the OEM magazines is that they have fairly soft springs,
but they can be upgraded with Wolff 11-pound springs. Metalform offers a
Wolff spring upgrade with a magazine order, and it's money well-spent.
I'd also pop the the small extra cost and go with their stainless mags. The
followers seem to be a little harder and tougher.

The Cobra is a good-quality magazine, but suffers from the same same...
Soft springs and a smooth follower. The two that I tried weren't consistent
in locking the slide in several pistols that were dead reliable on that function with all my magazines...and I have about 150 that I use for range work alone, and not counting my carry mags.

Of all the 8-round magazines on trhe current market, the McCormick Powermag...not the Shooting Star... seems to be the best of the bunch...but still gives some problems in some pistols such as the ones mentioned in the opening post. Not as often as 47Ds...but often enough.

Shooting Stars are made by Metalform, and have weak springs. The followers...although identical to the ones in the Powermags...don't seem to be of the same quality.

 

[Old Fuff]

A lot of folks could cure their problems with last-round feeding if they used the right magazines with the right springs - but they don't want to hear it!

If the latter-day magazine makers had wanted too they could have tooled in that dimple - even on rounded followers. They went wrong because they didn't do any research and discover why that dimple was there. The same can be said about some other popular aftermarket adaptations.

The reason the 1911 design is so good is that it came about through evolution - where prototypes were tested, problems were found - and then corrected - after which new prototypes were built and the trials repeated until most of the negatives were resolved. When the pistol is built the way it was supposed to be it works fine. When cost-cutting technologies and “improved†components are used the former reliability may go out the window because today’s makers don’t generally test their products very long (if at all) before they market them.

My point was to show that what you've claimed and explained is correct - and backed by evidence in the original trials that led to the 1911 .45 pistols.

You are right about the location of the dimple. I didn't go into detail because to be frank - with you around it isn't necessary.

 

[1911Tuner]

Frankly...

Ahhh...Thanks Fuff. My research on that dang dimple came about after learnin' about it the hard way.

When I was a young tuner, I picked up one of Ken Hallock's little paperbacks, mainly for the follower template...and read a section where he advised removing the dimple so that the last round would feed properly....
so I removed a few. The trouble started shortly afterward...so I put my thinkin' cap on, and after about three headaches and askin' my self the
classic question: "What's it FOR?" I came up with the answer, made a
simple punch and die, and replaced the dimples. Ba-Da-Bing! Problems went away. Case closed.

EDIT TO ADD:

Sorry...Got called away before I could finish.

One thing that I have noticed about the problematical magazine designs is that they don't produce the same problems when used in lightly sprung guns with downloaded ammo...or at least not nearly as often. Go back to full power stuff and standard spring rates throughout, and the problems return.

What conclusions can we draw from that?

------->(What is it FOR?)<-----

Cheers all!

TUner

 

[Old&Slow]

May I intrude on this thread to add to Tuners list and to say after experencing endless problems with all of the after market mags I tried the Wolff SS 7 rounders, which come with extra power spring & the classic dimpled follower and have had no mag related failures in several Colts and Kimbers.

 

[Jim K]

I am probably even older than Fuff, and I agree 100%. That dimple is there for a reason. I was told by one "expert" that the "progressive" mag makers didn't use it and that the feeding on his gun when he worked it by hand was a lot smoother. He did confess that there was sometimes a problem with the last round, but His Royal Expertness never connected that with the smooth feed in working the slide by hand.

Stiff springs are NOT a necessity in 1911 magazines. I have seen some that required the strength of "Aaahh-nold" to get the last round in, but still didn't work.

FWIW, I use nothing but WWII GI, Colt, or Norinco magazines except for 10 rounders for pin shooting. The GI magazines are still good, and if worn or a bit rusty can be bought for less than $10 at gun shows. The main thing is that they work, and many of the high-priced mags don't.

P.S. Don't be fooled by junk magazines with signs saying "mil surplus" or "GI" or by CAGE codes on the floorplate. Some on the market were made under contract, but rejected by the Army because they were out of spec and no good.

Jim

 

[Old Fuff]

Tuner:

Actually I discovered the same thing the same way ... reading books came later.

I have noticed in the past that you've often posted messages about feeding problems vs. magazines. You repeatedly have pointed out and explained about weak springs, 8-round magazines vs. 7-round, and followers - rounded vs. flat with dimples.

Never the less some folks keep coming back, and complaining about still having problems while still using their old magazines. Others say they’ve always used “brand-X†magazines and haven’t had any problems - at least so far. Why that may be I have no idea, but I am delighted in their good fortune, and hope it doesn’t change. To me what’s interesting are those who do have problems and refused to change. Even more distressing are those that use their pistols for personal protection and still won’t follow good advice.

I’ve decided that one cause of your opines being ignored is that for some unfathomable reason these people think you lack creditability - being some kind of an unlettered North Carolina redneck mechanic or some-such rather then someone who writes articles in the gunzines or supposedly builds world-class pistols.

The fact is, you are usually right. Something you’ve proved time after time. The reason you lack creditability with some is because they don’t understand even so much as a tiny fraction of the knowledge that experience has taught you, and they want whatever you say to be confirmed by some nebulous higher authority. This is bull, pure and simple! But when I get the opportunity I am going to provide that evidence, until some of your critics - as you put it in another context - “go suck air.â€

Meanwhile we may hope that some members and other visitors who come to this forum will begin to understand good advice when they read it, and discover to their considerable shock that when things are done right the old warhorse does indeed work, and work well.

 

[Jim K]

Hi, guys,

The fact is that Tuner well understands the dynamics of the 1911, something that many of the "experts" don't fully grasp. How a pistol works when it is hand operated or shown in drawings and how it works when actually fired are two different things. I have seen high speed photos of guns firing, and it is hard to believe how much a gun which operates so smoothly in manual operation will jiggle, and wiggle, and twist, and jump about when actually fired.

Jim

 

[1911Tuner]

Critics

LOL Fuff. I've heard it said that you can better judge a man's worth by his
adversaries than by his friends.

Jim Keenan said:

I have seen high speed photos of guns firing, and it is hard to believe how much a gun which operates so smoothly in manual operation will jiggle, and wiggle, and twist, and jump about when actually fired.

Yessir buddy! It's about like figgerin' a bench-rest group will determine how well you'll do on opening day when you're sittin' in a tree stand and it's 15 degrees with a 20 mph wind...and a Boone & Crockett buck steps outta the tree line.

On the magazine spring question...I completely agree that a Schwatzenegger Spring isn't necessary...but factory mag springs these days tend to be a little too soft...and last-round Rideover/Bolt-Over Base
feeds can occur with or without the dimple. We need enough spring...but there's no real need to overdo it. IMO, extremely heavy mag springs are
sorta along the same line of thought as using a 20 pound recoil soring in a
5-inch gun to solve a failure to return to battery problem...It covers up the
real issue.

I've found that Wolff 11-pound springs, once allowed to take a set, are just about right without being overly heavy. An alternative is the Wolff +5% spring, which is essentially the same spring as in the 8-round McCormick Powermag...used with a 7-round follower is a good compromise.
It combines close to optimum last-round tension without wearing out your thumb joint, and without stressing the welds on the magazine baseplates when left loaded for extended periods.

 

[Dave Sample]

I am old, but my magazines are not. If you like using Old Army Stuff, so be it. It is easy to blame malfunctions on everything except George Bush, but I would not, nor do I at the present time, have any dimples in followers. I guess that puts me in the "New School " of thinking about 1911 work. I find that most magazines with Dimples on the followers, are" Old School" thinking and to ignore the improvements we have made to JMB's wonderful 1911 is silly. None of my guns need "Dimples" to make them run. I guess I am just plain lucky!

 

[Old Fuff]

Tell us Dave ....

Does you use hand checkered, late model safety pins too?

 

[1911Tuner]

Old stuff/New stuff

Fuff...Behave yo' bad self!

EDITED:

Let's begin anew...Shall we?

I got me a splendid idea, Dave! Why don'tcha do a write-up on why the new, 8-round mags with the smooth-topped followers are an improvement
over the original design. Not: "They hold 8 rounds and they work good in my gun(s) now...Do a technical write-up and provide the reasons that they really are better. Show how the last-round can't possibly escape from the magazine without the dimple, and show how the shorter follower is more stable in the magazine on the last round or two than the longer, 7-round follower is. Then we can have two balanced viewpoints for everyone to consider....and they can draw their own conclusions.

Sound about right?

Standin by...

 

[1911Tuner]

Showtime!

Previous response edited. Time for a debate!

 

[Jammer Six]

Well, I'm relieved.

I thought you guys were going to do a group hug there for a while.

I'm looking forward to Sample's write up.

Carry on, gentlemen!

 

[Dave Sample]

Sorry Tuner, but I just don't have time. I have a new 1911 Online Class booked and am busy with all kinds of stuff. I love you and Old Fuff nipping at my heels and consider it part of the game. You do keep me thinking about the days of yesteryear. Speaking of the days of yesteryear, I had a gun return Friday that has been in Colorado for about six years. We estimate that it has had about 30,000 rounds through it and it still looks pretty good. It is one of those Blingers that you and Olf Fuff hate because it is a really neat gun and is kind of flashy, even though I built it 12 years ago. Hand cut checkering everywhere and about 80 hours of very hard work went into my end of the deal and some of the best machine work by Chuck Rogers that he ever did. After I made the post about the "No Stinking Dimples" I thought to myself. "Self! Those 38 Super magazines probably have dimpled followers!" Sure enough, they do. So I must apologize and just hope you can forgive a brain damaged old man for that error in reporting. Four of them are blue steel with electroless nickle on them and thay have served me well. One is a SS and seems to be doing OK. They all came from Chip McCormick back then and hold 9 rounds of Supers. So dimples do have their place in the sun and Old Fuff and Tuner win again!



I will tell you all one more time. I use CMC 8 round magazines loaded with 7 rounds. I use Wolff 7 round magazines loaded with 7 rounds once in a while. I perfer the 8/7 way because there is less pressure on the disconnector rail and I think my guns run better this way. (100%) I just have all these bad habits from 50 years of having a 1911 on my hip. I do not have to defend my opinions to anyone, because I am not a pit bull defending my turf like some people I know. I do not care who is right or wrong because I do not have these words in my vocabulary. I use positive and negative. Postive is what works for me and negative is what does't. When I played games with the Steel Gun, I loaded it with Nine and One in the chamber. It works just fine that way. It was my Bang and Clang Fun Gun![

 

[1911Tuner]

Dang Blang Dimples

AH...Okay Cap'n. Whenever ya get time, jump in and start one.
Them dang dimples got a job ta do, though...

Now...I never said I hated flashy pistoles...I just said that the flashy part ain't necessary if all a man wants is a solid, reliable pistol that'll do as good on an East Side Chicago street as it does in the boonies...and it won't cost near a much. Thassall I said. I like a purty gun as much as the next guy.
Don't much care for checkered steel though...not even on a mainspring housing...but that's just me.

Standin' by...

 

[Dave Sample]

I'll never smoke weed with Willie again.............................................and I'll never mention dimples again...............................................................let me count the dimples! 1-2-3-4-5 the end.

 

[Jammer Six]

'Tuner-Fuff-dimples, one, No time, zero.

Thanks for the reference, 'Fuff.

 

[Old Fuff]

The development of what became the “Pistol, Automatic, Caliber .45, M1911†was an evolutionary process consisting of building prototypes, testing them, reporting on the results and then building more improved prototypes and repeating the process over and over. Each test or “trial†was followed with a detailed report that pretty well documented what the problems or issues were and how they should be addressed. Because the design was pretty well de-bugged before it was adopted, rather then rushed to completion and then having its faults discovered later is one reason that after the passage of almost 94 years very few changes have been made, and most of those are more cosmetic then material.

As a consequence, reading those old Army reports of the pistol trials can be very illuminating and helpful in determining what happened when, and why. To truly understand the pistol it is necessary to know its history as well as its mechanical properties because one often relates to the other.

John Browning was a real “hands on†sort of guy. Where other companies usually sent mechanics or shop hands to disassemble and reassemble their prototypes, John Browning sent himself. He was the one who stripped his test models, and when he did so he inspected every part, especially any that failed. Thus he knew from personal knowledge what worked and what didn’t. Because of this his pistol may be less modern then others, but it is far from obsolete. Most of the problems we see today can be attributed to others, who many years later decided they could improve on what the inventor had accomplished. But all too often these improvements are illusionary and of questionable value.

I find it interesting that many of the points that Tuner brings up were discovered during the pistol’s early years, and that the suggestions he makes often parallel the solutions that were incorporated then. The “little dimple†on the magazine follower is only one example. But it is attention to these small details that can suddenly make a “jam-o-matic into a reliable and trustworthy sidearm.

 

[1911Tuner]

Dagnabbed Dimple

Okaaayyyyyy! Now that we've weathered a little storm, and at least raised a few logical points on why that thing's there...let's have a peek at the rest of the story.

We reference the second of Newton's dictums. We've established that the dimple is there to cover the one about objects at rest. It also addresses the "Side Opposite" and takes care of the one about: "Objects in motion tend to remain in motion."

When the recoiling slide hits the frame's impact surface formed by the guide rod head and the end of the spring tunnel, it bounces forward a little,
giving the recoil spring a little boost in returning the slide to battery. Incidentally, this is one of the reasons that a neoprene shock buffer may be detrimental to function.

The slide hits the next round and strips it from the magazine....but that statement would indicate that this event is smooth and gradual. It's not.
The slide kicks the round in the butt and knocks it loose from its position
in the magazine, hurtling it forward rather than pushing it, as shown in the animations. At this point, the slide isn't in contact with the round...It's chasing it. If the round is already slightly forward due to its' obeying Newton's first law, it's pretty easy to understand that it doesn't have to move too much further to escape from the magazine's control...unless there's somthing there to block its path. Heavy magazine spring tension might do it...but it's not really reliable enough to do it every time...with
apologies to the Powermag fans. The dimple blocks the path of the round.
The slide makes contact again, and with the round at the release point, it pops up under the extractor before it can get ahead of the slide again.

When the round gets to the release point in the magazine, it's gonna pop up...and if it pops up ahead of the extractor, it push feeds into the chamber ahead of the extractor. The round stops because the chamber
stops it. The slide...along with the extractor...catches up and the impact
either forces the extractor hook to climb over th rim...or the slide stops out of battery. Neither one is good for the extractor. If it climbs the rim and
allows the slide to go to battery, tension is quickly lost. If it impacts and
stops the slide, the result is a broken hook...usually sooner than later.

One of Browning's reasons for specifying spring-tempered steel for the extractor was to allow the pistol to be single-loaded in an emergency.
It doesn't mean that the extractor will tolerate a snapover feed on a regular basis...like about once every 8 rounds.

The sole reason for the dimple being there is feeding the last round correctly when spring tension from the magazines isn't sufficient to
fight the effects of Objects at Rest and Objects in Motion.

Download the gun by 15% so that it'll barely "Make Major" and spring it to match the ammo...and you can probably get by without it...especially if you use enough mag spring. Lighter bullets reduce the overall mass/weight of the round, and make it easier for the magazine to get the round up in time, and easier to hold it there. Lighter springs reduce the slide's speed and momentum so the slide doesn't kick it in the butt quite as hard.

Conclusion:

These magazines are for games. Just my 2% of a buck and not intended to
rattle anyone's cage. Remember: The magazine is NOT an accessory. It's part of the system. Change any part of the system, and it affects other functions of that system.

Cheers!

 

[Dienekes]

Tuner, I think you may be discussing the situation I have with a P-97 Ruger. I have had it a year and been routinely experiencing what I term "pop-outs". I have put a little over 1500 rounds through the gun and carefully documenting what it does. It's been driving me batty as I had never run into this in some 40 years of shooting 1911s. As you say, I will find a live round on the ground that was not there before, or the round will come out the top and fall on my forearm. Once in a while it will stay in the gun and get slightly cockeyed, and instead of chambering will hang up the nose on the barrel hood. Almost invariably it is the seventh round out of eight in the magazine that does it. 90% of the rounds fired have been the H&G #68 200 gr SWC and 7.0 gr. Unique, which is zippy but not excessive. The balance have been either factory 185 gr Federal JHP or a 230 gr RNL and 6.5 gr. Unique.

I have talked to Ruger's service rep (Mike Smisko) about this on three occasions. He has sent me replacement recoil springs, extractors, and new magazines to give me a total of five. ALL of them have continued to give me "pop-outs" to the rate of one every 34 rounds average.

Smisko commented that they had had some problems with their magazines related to the depth of the indentations on the rear of the feed lips that held the cartridge in place. On my own I began theorizing that the round was in fact moving forward in an uncontrolled fashion but attributed it to demonic posession. The last discussion I had with Ruger was that if the gun was still misbehaving to send it into them at their expense, which I will probably do. Needless to say I am not very happy with what is supposed to be the world's most reliable .45 auto--which this one is definitely not.

After reading this thread it seems to me that my suspicions may have some basis in fact. These (factory) mags are 8 rounders and have a plain flat follower with a slight up angle. At the rear of the lip surfaces there are distinct indentations which are obviously supposed to retard forward movement of the cartridge.

As I understand it Ruger has been using this same basic magazine since the introduction of the P-90, through the P-97, and now for the P-345--so it should be a proven design. These guns have a reputation for reliability so I am at something of a loss to understand why I have these problems.

I don't believe that there are any heavier springs available for this mag; at least I don't find any in the Brownell's catalogue.

I would be interested in your observations on this, as it is the first thing I have seen that bears on my possessed P-97.
I would be interested in your observations on this... (A PM if you prefer.)

 

[1911Tuner]

Pop-Out

Howdy Dienekes,

Since it's happening on the 7th round in an 8-round magazine, it's a weak spring issue. A call to Wolff might net a replacement spring...Some of the
parts vendors carry items that Brownells doesn't list. I'll also reply to your PM...