All current Production M3s are coming from cavities with the modification.

There are probably some new magazines still in the system that are unmodified, but back when we looked at it, it was a difference of just a few thousandths in magazines that would allow some degree of this to occur with the smallest ammunition. We removed the cavities from production that allowed it to occur with these conditions as we started modifying the cavities, so even the unmodified mags still in the marketplace are not likely to show much of an issue. The window mags never exhibited it at all due to all being on the smaller side of the tolerance range...once again, it's a tiny tiny difference in internal dimensions between those that allowed it and those that did not, and it certainly wasn't with all ammunitions.

Even when it did occur, insertion force still fell within normal ranges without readjusting the rounds in any way, although it was unacceptable to a very few users. It really is/was a non-issue in the 30 rounders except in some extreme cases--there are indeed some who have reported having problems-- so we addressed it across the board.

MRBF has not been affected either positively or negatively, nor have we seen any reported difference in side by side user experience evaluations with modified and unmodified magazines, so it will largely be transparent whether the mod is there or not, unless you are in a very, very small minority of rifle/ammo/perception categories.

The 40's don't have it as they are dimensioned slightly differently in that area, and the 10s don't have it, as the stack isn't tall enough to really allow it to occur to any extent.

Almost all of my black magazines are from the worst of the pre-fix mags, dimensionally that I deliberately rotated into my kit after the testing--meaning the most likely to allow problems to occur--and I can't tell any difference in normal usage with Magtech m193, PMC X-TAC, M855, BH Mk262 mod1, et.al. YMMV.

If you have issues with your M3s just contact Magpul Customer service. Most likely they will swap out the magazines for you.

Never worked properly? So that's why pretty much every top 3-gun competitor uses them (it's not sponsorships), numerous NATO militaries use them, we have a ton of Fed, State, and Local LE users, and they now comprise the majority of our US military sales, including entire units equipped with all GEN 3 PMAGs for workups and deployments, etc., etc.  I really, really wish we could post some of the third party testing. If you're .mil, you can request the data, then you'd see for yourself.

If you're happy with your current mags, great. If you are unhappy with some aspect of the GEN M3 magazine, then we'll take that on board, as we value customer input, and continually seek to improve both performance and user experience, with this change being a small part of that effort. If you're unhappy with any GEN 3, as Richard said, we are pretty much always willing to do what it takes to satisfy our customers.

But...we've got millions of M3s in worldwide service with very happy users, both pre and post the change referenced here, which is inconsequential and transparent to the vast majority of users. Suggesting that they don't work is just silly and obviously spiteful.

It is very common for us to trade out magazines having issues.

It actually helps us in the quality assurance dept as we keep track of issues as they occur in the field.

Did you bother to call Magpul?









Let me add that I ordered some of the Sand from DSG back in Early September and the date code was May 2015





 

Here is the full range test report posted a awhile back concerning this subject...

***Previous Posted Report***

I haven’t jumped in here ‘til now because we do in fact take every customer issue very seriously, and we wanted to do some additional testing of past and current product in order to have the most complete and absolute information. Although we looked at this exact occurrence in the PMAG30 in initial pre-release testing and again back when we looked at the PMAG20, we cleaned off the calendar and got busy at the range.

We’ve spent the last few days re-validating lab and range testing regarding the GEN M3 magazine and the behavior of the top two rounds, which we call “transposition”, just to make sure that nothing had changed, and that current results matched previous efforts. All molds, variants, and sizes have been looked at.

Since this thread got me out of the office and on the range, which I generally appreciate, I’ll give you the long version, so everyone that wants to wade through it will have the complete picture. Bear with me, it’s all relevant.

If you get bored with my rambling at any point, you can skip to the “Cliffs Notes” summary at the end.

The GEN M3 project began when we had accumulated significant enough advances in certain technologies to make a meaningful difference in some performance aspects, and to achieve universal fitment with Colt/M16/M4 and compatible platforms as well as platforms with the HK416/SA80 magwell. Although we already had a great track record in combat use and in many of these categories with the GENM2 or MREV PMAG, we never stop improvement efforts. Some of the aspects that we sought and achieved improvement on were drop-free performance in min-spec magwells, improved stiffness, strength, and durability, improved performance in cold weather to -60 deg F, improved performance in dust and grit, and overall feeding reliability.

These efforts resulted in a magazine that has been successful in achieving our goals, and that we are confident is the most reliable and durable magazine available. We’ve got over a quarter of a million rounds downrange at this point, it’s been through field trials with military units, it’s in law enforcement service, it’s been downrange, it is used by many of the most successful competitive shooters and trainers in the world, and we continually test for QC.

OK…this is where we tie this in to the issue at hand. I’ll talk about what you are seeing, and then I’ll tell you what our test results show. This requires us to share more about the PMAG than we’d like, but here goes…
Dust and grit are enemies of firearms and magazines in general. In current conflicts, as much or more so, than in any previous operational environment, these factors can be deadly if your gear can’t take it. The GEN M2 PMAG works very well in dust/grit tests, but we wanted to improve this with the Gen M3. Friction or drag on the stack/follower/individual rounds on the way to the chamber is what makes grit stop guns, and the PMAG combats this in numerous ways. Relevant to the current topic of discussion is the fact that we minimize the contact that the round has with other surfaces as much as possible. Less surface contact equals less drag. Feeding into the chamber is as important as when riding up the stack in the mag body. To minimize drag/friction, we minimize contact with mag/other cartridge surfaces while still completely and resiliently controlling feed geometry. To do this, you have to flirt with instability to some extent, and get the mix just right. Too much contact equals great control without optimized drag. Too little contact equals minimal drag and a mag that won’t feed worth a darn because presentation isn’t controlled. It’s a fine line. We’re always looking for ways to improve, but this is the best way we’ve found to do it, and it works very, very well.

This transposition is rare in other magazines, but can occur in some of the samples we’ve tested, probably due to tolerance variation more than design intent due to the inconsistency of its occurrence. It may occur with a flick, a smack, or extended carry in a pouch depending on the sample, but is generally less likely than with a PMAG.

All PMAGs play this balancing act very well, and especially in the GEN M3, this manifests itself in what may appear to be the rounds at the top of the stack having some “freedom”. With various manipulations of a loaded mag, you may indeed be able to induce this partial “transposition” of the top two rounds to a lesser or greater extent, depending a great deal on ammunition type/shoulder size. Smaller diameter ammunition shoulders, even a few thousandths, may allow this to occur more readily than larger diameter, but still in-spec ammunition. On a few of the PMAG20 GEN M3 magazines, there was enough of a tolerance stacking issue where you could indeed, with the right combination of gun, ammo, and mag, induce a failure that would not allow seating, but we have not seen that since the fix for those affected mags, or in any other magazines across the entire line, without deliberately setting up a failure by prying up the round with a tool, to the same extent that you can do that in any other magazine, and believe me, we’ve tested a lot of combinations. The PMAG20 was long ago corrected, and we monitor this in QC with all mags.

As long as loaded rounds do not to creep forward enough to catch the front edge of the mag when you try to insert it (possible with any magazine…try it) you should have no problem inserting and locking the magazine on a closed bolt, regardless of the position of the rounds with respect to this transposition occurrence. The required force may increase a bit, but we’ll get to how much in a minute--certainly nothing unreasonable. The first time the bolt starts rearward, the stack self-corrects, if it hasn’t already self-corrected on insertion. If I had a nickel for every time we’ve tested this on the GEN M3 mags to prove it, I’d be typing this from a hammock in Fiji.

To illustrate what I’m talking about, I’ll cover some of our testing.

In the lab, we assemble magazines from every line, deliberately induce a transposition with a variety of ammunition, and then measure insertion force on a closed bolt with a fixture and a force gauge. FWIW, the normal force required to seat a fully loaded PMAG on a closed bolt, depending on firearm and ammunition, is around 14-17lbs. The worst cases of transposition induced by any method other than using a tool to deliberately pry a round up require a closed bolt seating pressure of 28-31lbs, and most are less. You may say, “Whoa, there…that’s double!” However, when you put it in context, it changes a bit. The seating force required to seat an ideal condition USGI loaded with 28, 29, or 30 rounds (We baseline all 3 loading conditions) averages 15-21 lbs, and when we set up transpositions on the USGI by impacts to the magazine, flicking, or in some cases prying as with the worst case deliberate PMAG transpositions, the force varied from 32-47lbs, with some outliers in the 50’s and 60’s. The transposition occurs more readily in most, but not all combinations of PMAG and ammunition, than in other magazines, as it should…because this is a side-effect of our intended geometry. However, in magazines where it occurs more easily, it also CORRECTS more easily, and the force variability is smaller. This should put the numbers in perspective, and yes, we have people who spend days at a time beating, flicking, slapping, dropping and abusing magazines and then putting them into rifles using a force gauge. We wouldn’t be what we are without them.

On the range we do variations of this in actual usage as well as in set ups that are more regimented. The Product Management/Dynamics portion of this testing this week, to exhaustively vet the issue with our crew personally prior to writing this, went something like this:
Loaded magazines, samples from each line, tac reloading: Fire 2 rounds, tactical reload, fire 2 rounds, etc. Between tactical reloads, magazines were handled in a manner that attempted to deliberately induce the transposition.
Load magazines fully. With an already loaded chamber, deliberately set up a transposition. If we couldn’t get it by other means, we’d pry the round up with another loaded round or knife blade until we got a nasty one. Insert and lock the mag, assessing required force. Fire 3 rounds. Remove magazine. Repeat setup and firing until mag empty.

Load mags. Place in plate carrier. Do “burpees”, run sprints, roll on ground, slap mag pouches, chest bump, etc., then tac reload repeatedly to cycle through mags in carrier to see to what seating forces we’d see and see if we could unintentionally get transpositions. Repeat with various numbers of rounds in magazine, below maximum capacity.

Here’s what I can tell you about the PMAG GEN M3. In the thousands of times we’ve deliberately set these transpositions up previously, and in the hundreds of times today, not in ANY case have we been able to cause a malfunction of the firearm. EVERY time, it has fired, ejected, and fed flawlessly from a deliberate attempt to get the nastiest condition possible.

The only time that significant force was required to seat the mag was when the transposition had to be forcibly created with a prying tool in a specific magazine/ammunition combination. In these combinations, unintentional transpositions or transpositions using any method besides prying were simply not possible, and had to be forced—just like you can do with any other magazine. All other seating forces were in line with the previous ranges in lab testing. (Regardless of seating force, once again…100% reliability in function)

In tactical reloading/closed bolt reloading, in actual usage or field/range testing, we have NEVER seen a case where this issue prevented magazine insertion. Increased force required tending toward the higher end of the previously discussed range, occasionally? Yes, but it’s not something you notice more than casually when using a sound push/pull mag swap, unless you are specifically looking for it.

So…is there a safety of use or reliability issue? No, if the magazine is inserted and locked in the rifle the magazine will run normally.

“Cliffs Notes” summary if you got tired halfway through:

The occurrence referenced by the OP is a side effect of design geometry that aids magazine function in adverse conditions by minimizing round contact with other surfaces at and near feeding position.

The only “negative” implications of this “transposition” effect is an occasional increase in closed bolt seating force over “ideal” round stack conditions. This seating force may vary slightly based on ammunition tolerances and magwell size in the host firearm, but in all but willfully deliberate setups requiring the use of a prying tool, falls well within the realm of normal closed bolt insertion pressures for USGI and other competing magazines. I can bore you with standard deviations from the mean, etc., but I’ll spare you the pain.

Although this transposition naturally occurs more rarely in USGI and other magazines, it can be induced in many samples through rough handling without prying, and it can indeed be induced with a prying tool, just like in the forced setups we had to do in many of our PMAG test combinations. These transpositions, especially in a USGI, may appear less significant, but may require much more force to seat when they occur.

In THOUSANDS of deliberate setups, at no time has this occurrence EVER caused a failure to feed or function in all of our body of testing.

With the exception of the previously corrected batch of GEN M3 20rd mags, in no case, in our entire body of testing of PMAGs (or any other mags, for that matter) has a transposition caused an inability to seat the mag unless the transposition was so difficult to induce as to require a prying tool of some sort, and be completely out of the realm of anything we’ve ever seen occur through any other means. This type of transposition is duplicatable in ANY AR-pattern magazine.

What we are going to do:

Although we have not seen any incidences in a vast body of testing where this occurrence creates any functional concern, we will set in place a tighter tolerance level in the area of the Gen M3s that allows this transposition to happen in order to address the perception of a problem. This will resolve any issue of noticeably higher force to insert a magazine in the most extreme cases, and even further reduce the likelihood of unintentional occurrence of transposition that affects insertion in any meaningful way. The vast majority of Gen M3s already fielded are already within this tolerance, and our ongoing testing shows that we do not lose any adverse condition function with magazines on the tighter end of this acceptable window, so there is no reason to not clamp it down a bit.

Anyone with Gen M3 magazines that require more force than they feel is acceptable or normal to insert can contact us for a one for one replacement with Gen M3 magazines that will be tested to be within the tighter end of the tolerance range. Those who are comfortable with the insertion characteristics of their existing magazines can rest assured that there are absolutely zero reliability or functional concerns.