Did a quick search and could not find the answer.

I live in NJ and had to purchase 10-round mags. Problem is I can't fit all 10 rounds without them being so tight that its causing me failures to feed, specially on my PCC that uses my M&P magazines. If I only feed 9 rounds there's no problem.

Is there a mod that can be done to the top of the magazine pad or spring that will release the tension?

Asking before I start messing with the mags and screwing them up. I'm hoping that somebody has solved this problem.

TIA.

I recently ordered two 10 round 9mm 1911 magazines from my usual supplier. When they arrived I found that they were the same brand as another 10 round mag I had been using for some time with no issues.

The new mags were hard to load and misfed the first round. I cut a coil off the springs, same result so I cut another coil, then a third. Eventually the mags would not work!

When I placed the new mag against a proven 10 round one I saw it was a bit shorter. Obviously despite having 10 numbered sight holes down the body of the mags they were 9 rounders not 10.

Funny thing is that they be original mag now fails to take 10 rounds too.

Go figure that one out.

I would say you have 9 round mags that have been mislabeled. The only way you’ll know is to measure the length against a known 10 round mag.

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View from down under

Thanks Kiwi cop. They are the original M&P 10-round magazines.

I thought about cutting a coil off the spring but before I do that I'm hoping somebody will post to what they did to fix the problem

I get crazy when I hear about cutting coils off springs. It never ends well ...

Try loading the mags up, and leave them loaded for a few days, unload, reload, ....
Cycling the springs may weaken them a bit.

If for some reason you can't have the mags loaded at home, press down the follower as low as possible, and pin it with a small screwdriver or nail through witness holes.

Some mags work great from the box, others not so well.

One-word solution: Uplula.

I've never met a magazine that my Uplula loader couldn't fill.

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What, me worry?

I wonder if the follower is bottoming out?

100% agree, Uplula is is great thumb saver and loads everything faster too.

Yes Uplula is the way to go.
I use Wilson Combat mags for my 9mm 1911 and they suggest in loading the mag and letting it sit for a while to break it in.
I’ve had mags from various manufacturers be hard to load the last round when new and the Uplula always gets it in.


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This is a common problem with new mags. New Glock mag springs are notorious for being STIFF-- you need a bumper jack or an Uplula loader to get them fully loaded.

New coil springs (like those used in the recoil spring assembly and magazines) will take a set quickly with first usages -- but it may take a while before you notice a big change.

Solution: load the mags fully and leave them loaded for a week or two.

In the meantime, until the springs relax a bit, insert the mag with the slide locked back, and release the slide for the first round.

While cycling will wear down a mag over time, it's a very slow process -- the springs may outlive the gun! Leaving the mags fully loaded will generally do the same thing as cycling, but do it more quickly.

It's not really CYCLING that wears out a spring, but the deep compression of the spring that occurs during the firing cycle. While cycling compresses the spring, leaving it loaded has the same effect as multiple cycles -- because a deeply compressed spring is a spring that is still working and subject to stress and that stress can lead to metal fatigue, if the spring isn't relaxed.

With most mags, you'll see some quick spring relaxation as the springs take a set -- and it won't degrade a lot further for a long, long time. But, not all springs degrade (weaken) at the same rate.

The original 7-round 1911 mag springs almost NEVER wear out, even when left fully loaded for decades -- that design didn't ask much of the springs. The early 8-rounders were horrible performers, until they redesigned the mag followers to give the springs a bit more space (and less compression).

Spring wear happens when the spring is compressed near or beyond its elastic limit -- the point where the metal begins to slowly fatigue. Not all gun designs push springs that hard, but some do (and do so intentionally) to get more rounds into the same space.

Farigue is a function of repetition and the number of Cycles.

Creep is the term that occurs when set in steady state. This is the “set” that occurs from fully loading and leaving the spring compressed for a few weeks. The initial creep of the metal’s atom molecules. Changing from the initial state, to the springs working state.

I creep is from my understanding typically fairly constant rate. So I cannot completely explain why there seems to be an initial creep rate, and then then the rate of creep plateau’s, or slows down after this initial set.

Therefore I suggest that the steady state loaded mag affect on the spring is technically creep, while the cycles of extension and compression from being fired by the RSA is a fatigue issue.

Spring metal fatigue due to repetitive cycles wear them out faster than creep causes them to go “flat”.

We've discussed this on THE HIGH ROAD a number of times, and a metallurgist or two has joined in the discussion. When a spring is at its elastic limit (as is often the case with SOME high-cap mags), creep is no longer the action affecting the metal -- it is actual metal fatigue.

The experts say that cycling isn't necessarily a big deal as long as the springs, when cycling, don't approach the elastic limits of the metal used. When they do approach that limit static compression and it's consequences becomes the problem.

Note: if cycling was the only issue, you'd expect recoil springs to have to be replaced much more often than they area as, depending on the gun, a recoil spring may cycles 10-15 times more often than a magazine spring. Even if you use several magazines, there's no comparison in the number of cycles performed. And recoil springs are often quite deeply compressed when the slide is fully to the rear, while the mag springs may NOT be near fully-compressed when it is full. (Hi-cap mags sometimes are, but any non-hi-cap full-size mag springs are probably are not near fully compressed.)

Generally speaking, many (maybe most) mag springs DON'T reach or exceed their elastic limit -- but when they do, it's no longer creep, put classical fatigue. And some hi-cap mags are intentionally designed to reach or exceed their elastic limit, because doing so allows an extra round or two to be used in exchange for a short service life. A lot of shooters thing that's a fair exchange.

For standard usage, even, cycling isn't that much of a problem -- that's why standard capacity mag springs seem to live forever. But high caps, which are compressed farther when cycling, and also compressed greatly when stored fully loaded, fail.

The NEGATIVE example that always comes to mind is the recoil spring in the Rohrbaguh R9, the smallest 9mm available (until Rohrbaugh sold to Remington.) The R9's recoil spring has a recommended service life of 250 cycles. Other recoil springs last a lot longer -- but because the R9's spring must do the same work as a full-size spring in a smaller area, using less metal, it doesn't last as long. It's not cycling alone that is the issue, but how much work the spring does, and how much spring material is involved when it cycles, and how close to the elastic limits that spring moves to.

The only way to increase recoil spring life in a Rohrbaugh R9 was to make it of heavier material (and much harder to rack), or give the spring more room, which meant a longer gun. And that wasn't Rohrbaugh design objective. The springs weren't that expensive, and the people carrying guns seem happy with the trade-off. (You could probably use the "expired" springs at the range, for practice, for another 100 cycles or so...)

Here are some interesting links from earlier discussions on THR, but I think the first one addresses the point of fatigue due to a static position. A forum member who works in the industry provided the links. A number of engineers, most in aerospace, have been involved in the discussion.

Spring durability and spring fatigue are of great interest for springs

Yield Strength - Strength ( Mechanics ) of Materials - Engineers Edge

Compression Spring - Stress and Spring Set

http://www.db-thueringen.de/servlets...011iwk-064.pdf

http://www.db-thueringen.de/servlets...011iwk-064.pdf

Here's an article from Ballistics101, a web site that seems to generally have it's technical stuff together. It addresses, in a non-technical way, the topic we're discussing.

http://www.ballistics101.com/mag_spring_experiment.php

Finally, here's a long-term spring test undertaken by a staff member of The Firing Line, JohnKSa, who is an engineer and ALSO an airgun enthusiast. He previously cited information from that discipline -- where they all consider it a no-no to leave an air gun fully cocked, and where coil spring technology is regularly pushed to its limits. In his tests, he shows that with Glock and Ruger mags, there can be pretty substantial spring degradation that happens pretty quickly, but despite that degradation, the mags continue to function. With lower quality springs, function may go away. (That often seems to be the case with Pro-Mag springs for some guns.)

https://thefiringline.com/forums/sho...56#post6005156

Chances are the issue is with the follower and not the spring. The "legs" on the bottom of the follower serve as stops to limit travel. They actually contact the floorplate of the magazine when fully compressed. Try trimming the back leg(s) slightly, not over 1/32", and I will bet you can load the 10th round much more easiiy. The follower legs are the reason trimming the spring doesn't work!

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Gunsmithing since 1961

That's what I was wondering back about post #5.

I didn't see what your caliber was. I received three M&P 45 mags #19469 that were suppose to be 10 rounders. However, they would only take 9! I tried an UPLULA and also kept them loaded for awhile, all to no avail. Then I came across an article (after an Internet search) that compared the 10 round follower to the 9 rounders and the legs were different lengths. The article went on to tell you how to "fix" this problem. I don't cut springs and I don't file followers, so now the three mags are in my range box. So there is a fix out there.

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Just an economic refugee
"You can never go home anymore"

A long time back when I got my first M&P 9c, I couldn't get 12 rounds into the mags, I fooled around with filing the followers, still no good. Then one day I had all my mags disassembled for cleaning and was looking at the mag spring for the 12 rounder, and then the 17 rounder I discovered that both springs were of the same gauge and number of coils. Apparently Smith thought it was easier to have on less part number in inventory . The fix was to clip one loop off the bottom of the spring. Worked like a champ after that. I know some people freak at the idea of trimming a spring, but it's the same thing as putting a lighter spring in (except the lighter spring still stacks up and prevents loading the last round)

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Minimize the variables

CZ used the same springs for their 10, 15, and 16 round mags for a number of years. Don't know if they still do.

When I was using them a lot (i.e., for IDPA) the 10-round mag springs seemed to last forever, while the service life of the 15 and 16 (and now higher capacity) springs seemed a bit less long.

I've had some success in taking a pair of needle nose pliers and very slightly bending different places on the coil. You just do enough bending to get the spring unloaded enough to do the job. If done carefully, this fix is 'reversible' to some extent.

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"He was kinda funny lookin'"

Trim the "legs" on the bottom of the magazine followers. I had the same problem here in New Yuck a while back and trimming the followers solved it.
The 10th round loaded easier and there was no problem with feeding, etc.

Check the attached pics to gauge how much to remove.

Attached Images

	IMG_3972.JPG (131.0 KB, 33 views)
	IMG_3973.JPG (127.0 KB, 32 views)

Your spring may be bound up.

When I got my Shield new, I couldn't get the full number of rounds in the mag. So, I took the mag apart and this is what my spring looked like:


At least in my case, it had nothing to do with being difficult to load, the spring was buggered.

So, take your mag apart and look at the spring. It may need to be replaced.

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Freedom isn't free.