Jump the Bump Part III: Springing Into Action

[Candiru]

A while back I posted several threads on thehighroad.org concerning problems I had with a Springfield Armory Mil-Spec and hollowpoint ammo. The last round in a standard 7-round stainless magazine was jumping the dimple on the follower and getting ahead of the extractor, causing a failure to go into battery. Per 1911Tuner's expert recommendations, I put Wolff springs in the magazines. This solved the problem...at first.

Then last week I went to the range and dragged along my 1911 to shoot off the mag of carry ammo that had been sitting in it for a while. Lo and behold, the last round failed to go into battery. Highly disconcerting from a gun I had been carrying, and whose magazines I thought I'd fixed.

I had two stainless mags with Wolff springs, so I swapped the malfunctioning magazine's follower out for a follower with a more pronounced dimple and took the magazine to the range. I took its unaltered twin along as a control for the experiment.

Sometimes, though, science is just frustrating. Although I got no failures in the magazine with the swapped-out follower, neither did I get a single hiccup from the stock magazine, the same kind as the one that had failed.

This made me think: What if the failure to go into battery I experienced, which was exactly the kind of failure to be expected from a magazine with a too-weak spring, occurred because the magazine had been sitting in the gun, compressed under a chambered round, for the better part of a month? If the spring took a temporary set, that would explain why I ran into a failure while shooting the mag, but the behavior was unreproducible after the magazines sat empty for a week.

So my question to the knowledgeable folks of this forum is this: Have you ever run into a situation where leaving a gun loaded for extended periods of time weakens the mag springs? If so, how often do you rotate your magazines?

On a side note, it can sometimes be frustrating to talk about problems like this to people who don't really care why problems happen and how to find the correct solution to them. I've had several conversations offline and on where the topic of my recurring feeding issue came up. They almost all went like this:

Candiru: I seem to be having a problem with my magazines where there's a failure to go into battery on the last rou--

Other Guy (OG): USE WILSON 47D MAGS THEY'RE GREAT

Candiru: Thing is, I think it's a problem with either spring tension, friction between the round and the follower, or--

OG: I'VE BEEN USING WILSON MAGS FOR YEARS AND THEY'VE WORKED GREAT

Candiru: Wilson magazines have a smooth follower, so that might just mask the problem by letting the extractor snap over the rim, which over time would wear--

OG: LOOK BUDDY I HAVE YEARS OF EXPERIENCE TUNING 1911s SO IF YOU THINK YOU KNOW BETTER THAN THE ENTIRE 1911 COMMUNITY WHY DON'T YOU JUST USE BALL AMMO FOR EVERYTHING

Candiru: Never mind.

[1911Tuner]

Howdy Candiru. I feel yer pain...

Jumping the follower is an issue that pops up from time to time, and doesn't seem to follow any set pattern. A magazine may do it once, and never do it again. Other times, it's intermittent...comes and goes...seemingly at whim.
The Wolff spring cure cures it with about 99% certainty in a given magazine, (Asuming that the magazine isn't damaged or too far out of spec) but there's always that one per cent chance that it'll happen despite your best efforts.

Causes can range from a tolerance stack on the dimple location and feed lip release point to spring set...though with good springs, it's not highly likely.
I've left magazines loaded for months with no ill effects. Not to say that it can't happen...just that it's not very likely.

Other things can be the width of the feed lips being too wide, or magazine
springing open and letting the rounds position themselves high enough that the rims skip over the dimple. Although I've had excellent service from Metalform magazines...occasionally a bad one just slips through the cracks.
That happens with anything that's mass-produced.

Measure the width of your offending magazine across the flat area behind the release point. It should be .535 inch +/- .005 or so. Too narrow and you get sluggish release and the occasional nose-dive. Too wide, and you get premature release, usually on the last round, and ...if the spring gets too far gone...on the next-to-last round. The latter situation can often cause weird problems like ejecting the next-to-last round, and chambering the last one...
or slide locked with the last round sittin' there on top of the magazine, thumbin' its nose.

You can usually repair magazines with overwidth feed lip dimensions byt squeezing them in a vise. EASY does it. My preferred method is to use a hammer on'em. :scared: :D

To beat'em into submission, you'll need a 4-ounce hammer...three dummy rounds...and a hard, flat surface. Dummy rounds in place, lay it flat and rap on one side, then the other...checking the width as you go. The reason that this works well is that the magazines have some spring temper, and spring tempered steel generally reacts more readily to shock than just squeezing,
and doesn't run the risk of crushing like the vise method. Squeezing with the dummy rounds doesn't work well, and squeezing without the dummies
runs a high risk of crushing beyond the point of no return.

[Iron bottom]

Tuner; Do you think under the forces of recoil (back and upwards) rounds could momentarily slip back down in the magazine far enough to cause problems? I understand the dimple stopping the foward motion, but nothing checks the downward motion if in fact it even occurs.

[1911Tuner]

Tuner; Do you think under the forces of recoil (back and upwards) rounds could momentarily slip back down in the magazine far enough to cause problems? I understand the dimple stopping the foward motion, but nothing checks the downward motion if in fact it even occurs.

IronBottom...I absolutely do believe that it can and does occur, and have described how it does it in a sticky thread...somewhere.That's why I push the Wolff 11-pound mag springs.

I don't think it's as likely to cause a problem after the round gets to the feed lips as it does before it gets there. Mostly theorttical, but it starts to make sense if ya study on it for a minute.

Slide is moving rearward...Round is moving up toward feed position, and bumps
empty case just before ejection. (Extended ejectors don't let this part occur because the slide is still holding the upcoming round below feed position.)
Empty case delays the round for a nanosecond, and the spring has to work harder to catch up. Just about the time the spring is getting the round to the top...WHAM...The slide hits the frame, torquing the gun up and rearward, and the round's inertia compresses the spring just a little. The round is "floating" and the pistol is still moving up and back, while the floater's inertia causes it to stand still...and the pistol is literally jerked out from under it. If the rim catches on the dimple, all is well. If it skids across it, the round either jumps the follower and gets loose...and the slide locks...or the slide knocks it into the chamber ahead of the extractor.

Enough mag spring tension is essential. The dimple is mainly a backup that acts as a "booster" of sorts and provides a little higher lift at the critical moment, and...failing that...offers something to stop the round's forward movement. (Which is actually the pistol's REARWARD movement.)

The goal is to keep the rim from reaching the magazine's release point until the slide is pushing it. The most important player in all this, though...is enough mag spring tension, and fast spring action.
The first is dictated by wire diameter and/or temper. The second is dictated by the spring's rate...The first is the load. The second is the speed at which the spring unloads its energy. The two are related, but they're not the same.

[Iron bottom]

I would think that given the weight distribution on a round, it would tend to nose dive back into the magazine during recoil. Do you think tweaking the magazine spring to give the front of the follower a little more push than the rear would be of any benefit? I have seen this on other magazines. BTW, saw a .22 magazine the other day with the ramp built in the magazine.

[1911Tuner]

Well...it would seem that way, and likely would be the case except the time frame is so short that the round doesn't really have time to orient itself. By the time it noses down, it's either been snapped back against the lips, or has already made good its escape.

I've tweaked the top coil of mag springs under certain conditions, but in general, the "No such thing as a free lunch" applies. Bending the front part of the coil upward to a sharper angle, also shortens the coil...plus any benefit
gaine by applying more tension to the front of the round will cause you to lose
at the rear. (Then, there's the problem with exceeding the elastic limit of the sprin to get the bend. That weakens the spring at that point, and it usually collapses shortly afterward.) If the rear doesn't get into place in time, you Bolt-Over Base FTF can be the result. Of course, the follower's angle has an effect on that too. I've usually had better results with a small amount of bend on the follower than bending springs.

[garrettwc]

Howdy Candiru. I feel yer pain...
+1. That's the reason I spend 80% of my online time here, and the balance on a tactics related forum with people who have actually "gone to war" using the 1911. The BS factor is much less.

Welcome aboard.

Other things can be the width of the feed lips being too wide, or magazine
springing open and letting the rounds position themselves high enough that the rims skip over the dimple.
I'm slow but I'm learning. When I read he had already covered springs, dimples, and 7rds vs. 8; I immediately thought feed lips. Sounds like I mostly have the magazine function down.

Only about 20 more parts to gο. ;)

[Candiru]

Measure the width of your offending magazine across the flat area behind the release point. It should be .535 inch +/- .005 or so. Too narrow and you get sluggish release and the occasional nose-dive. Too wide, and you get premature release, usually on the last round, and ...if the spring gets too far gone...on the next-to-last round. The latter situation can often cause weird problems like ejecting the next-to-last round, and chambering the last one...
or slide locked with the last round sittin' there on top of the magazine, thumbin' its nose.

I must be measuring the wrong thing because my numbers aren't even within shouting distance of yours; the outside of the magazine just before where the lips start to flare measures almost exactly 0.55"; the distance between the lips at the top of the mag right above the follower at the same point is 0.398". Distance between the lips at the rear of the magazine is 0.38"; distance just before the flare is 0.398". On all followers, the center of the dimple is located 0.66" back from the front of the follower.

Dimensionally, all the mags are the same, so if they're out of spec, then they manage to be out off spec very consistently.

I forgot to mention that on the trip where I ran into last-round jams, there was also one case of premature slide lock. That would pretty much match with tired springs plus overwide feed lips.

[1911Tuner]

Candiru,

Measure across the flat ahead of the release point..at the TOP of the magazine. .550 indicates that it's .015 inch wider than mid-spec...if you took the measurement at the top.

Across the inside of the captive area at .398 inch is aso about .015 above mid-spec...I think you've identified your problem. The round is likely escaping
behind ahead of the dimple...that is...before the rim gets TO it. The lips
tend to flex open and let the round pop up too early. In your case, it's probably just AS the rim reaches the rear of the dimple. Otherwise, you'd
probably see the malfunction occur at other points in the magazine.

Many people don't take into consideration that the magazine is a spring, too.
I often refer to it as "The Forgotten Spring."

You may be able to temporarily address the malfunction with a dummy round and a vise. Place one dummy in the magazine, and squeeze lightly. Leave it in the vise for a few minutes, remove the dummy, and measure across the
inside again...where you got .398 inch. Repeat, with a little heavier squeeze until you get that dimension down to .390 inch. That's the top-end of tolerance. If you can get it to that, lay it on a flat surface and rap the flat area at the TOP with a hammer...first one side then the other...until you can close it up to .385-.388 inch. The shock may make the fix permanent, and it may return in time to the original width. I've had about 80% success rate with this method...and about a 50/50 chance that the fix is permanent.

Keep us posted...

[Candiru]

You may be able to temporarily address the malfunction with a dummy round and a vise. Place one dummy in the magazine, and squeeze lightly. Leave it in the vise for a few minutes, remove the dummy, and measure across the
inside again...where you got .398 inch. Repeat, with a little heavier squeeze until you get that dimension down to .390 inch. That's the top-end of tolerance. If you can get it to that, lay it on a flat surface and rap the flat area at the TOP with a hammer...first one side then the other...until you can close it up to .385-.388 inch. The shock may make the fix permanent, and it may return in time to the original width. I've had about 80% success rate with this method...and about a 50/50 chance that the fix is permanent.

Keep us posted...
Just a couple questions before performing mag surgery:

1. Do you recommend squeezing the entire mag, the top half, or just the part occupied by the dummy round? My guess is the latter, but it's hard to make educated guesses about subjects in which one is not that educated. If it is the case that I'm gonna be squeezing the area occupied by the dummy round, would there be any advantage to adding more dummy rounds so that I could squeeze more of the mag?

2. Earlier you mentioned hammering into shape OR using a vise; your suggestion here uses both. Is the preliminary vise squeeze to eliminate the need for excessive hammering?

As luck would have it, I happen to have a 4 oz. brass hammer handy in addition to a vice. Having the appropriate tool for the job at hand, in my case, is unique enough to constitute an omen--hopefully good.

[1911Tuner]

Howdy Candiru,

On #1...Correct. Just the area occupied by the dummy.

On #2...Correct again...sorta. Squeezing first gives you an idea as to whether the magazine has sprung...and how much...or if the present dimension is as manufactured. If you don't get any reduction in size with the vise, it was made that way. If you do, it's sprung. Shocking the steel with the hammer sometimes changes its "memory" and maintains the new dimension
better and longer. If it's sprung, it probably won't last as long as it will if it's
manufactured out of spec. Sometimes it works...sometimes not. Depends on
the quality of the steel and the tempering. One way to look at it is...If you can fix it, you've saved the cost of replacing it. Worth a 5-minute investment in time.

On #3...The brass hammer will work okay, but a hardened steel hammer will work better. Brass tends to dampen shock instead of transmitting it to the workpiece. When you hit, try to hit sharply and pull the hammer away from the magazine quickly. You're not trying to deform the steel so much as you're trying to shock it. Study on that for a minute or two and it'll make sense. Think...piano tuner striking a tuning fork instead of a blacksmith forging a horseshoe.

[Candiru]

The little lightbulb came on over my head when you mentioned the sharp rap for adjusting the shape of the steel--this must work on the same principle that gives steel its strength. Given a certain amount of sharp force, steel will compress or bend to a certain point, then stop deforming unless the force increases. I read that this is why steel frames can last indefinitely provided they're built properly.

Returning to the problem at hand, fifteen minutes in the Vice of Correction did not change the width of the lips in the captive area, nor did some pretty smart raps from the hammer. It looks like the mags are solidly put together, just not in the right shape.

Any recommendations for good stainless magazines?

[1911Tuner]

Candiru...check the inside measurement. That's the critical dimension that controls the release. You may have changed that regardless of the outside dimension.

Try rapping on it again without the dummy. Just don't smack it with as much force, and alternate sides on every strike. If you can get the inside dimension down to .385, the magazine will probably work. Might take 10-12
strikes per side, but you can get it to move. Keep the strikes close to the front/top so you don't run the risk of collapsing the tube below the lips. Let me know if this doesn't do it. I've got one more little trick up my sleeve.

For stainless magazines...Metalform. Pop the extra two bucks or so for the Wolff springs.

[Candiru]

Candiru...check the inside measurement. That's the critical dimension that controls the release. You may have changed that regardless of the outside dimension.

I've been checking the inside measurement, and it looks like it has been staying put.


Try rapping on it again without the dummy. Just don't smack it with as much force, and alternate sides on every strike. If you can get the inside dimension down to .385, the magazine will probably work. Might take 10-12
strikes per side, but you can get it to move. Keep the strikes close to the front/top so you don't run the risk of collapsing the tube below the lips. Let me know if this doesn't do it. I've got one more little trick up my sleeve.

Tried this too, on the hunch that the dummy might be redirecting the energy down into the spring. Didn't seem to make much of a difference. All of my hits have been within a half inch of the top of the mag. I'll give it one more try just to make sure.

Edit: Nope, that didn't seem to do anything. I'm pretty sure I'm not wimping out about the amount of force used, either.

[1911Tuner]

Well sir...Sounds like a simple case of a bad magazine. It happens. Things have to be within spec, and the magazine isn't exempt from that. The manufacturer MAY warranty it...but most take the stance that it "Falls within *our* acceptable specifications"...whatever that means.

[Candiru]

Thanks for all your help. I really do appreciate it. Looks like I'll be investing in some Metalform mags and seeing in Springfield will pony up some replacements.

[Candiru]

Hmm. Looking at Metalform's website, it looks like what I want is part 45-793W (7 round, stainless tube, flat follower, welded base). Springfield's FBI mag (45-793FBI) also looks it might fit the bill, but I don't see any difference betwen it and the 793W except for the "FBI" in the serial number.

What I'm not seeing is where one adds Wolff springs to them--or do you just get mag springs separately and swap 'em out?

Edit: Oh wait, that's the "W" on the end of the serial number, isn't it?

[1911Tuner]

When you call in your order, you have to specify the Wolff spring upgrade.
Ginny will probably ask, but if she doesn't, remind her. AND...specify the 7-round followers with the dimple. I think the FBI magazine has a thin base pad.

There's a group buy going on over on the Magazines board. Deadline is June 29th. That'll get you the magazines for about 12 bucks a copy. Otherwise, you pay full boat retail for anything under 40 mags.

[garrettwc]

that's the "W" on the end of the serial number, isn't it
No I think the W is for welded base pad.