Why do some work in a rifle and some don’t? I have gen 2s that won’t seat on a closed bolt without getting slapped hard. Range mags for sure.

These magazines are loaded with 30 rounds when you're trying to lock them in the rifle?

That's not normal for a PMAG. They're intentionally designed with some extra space for the spring to compress further once fully loaded, to allow the magazine to be easily seated on a closed bolt even when loaded with 30 rounds.

However, this extra wiggle room means that it's possible to force 31 rounds into some/most PMAGs, and doing so would make it very hard (if not nigh-impossible) to seat on a closed bolt.

Count the rounds while you load them, and only load 30... don't just load it until you physically can't cram any more in.


(USGI magazines, on the other hand, can typically be tough to seat on a closed bolt when loaded to 30, since they lack this extra wiggle room. As a result, some people will download them to 29 or even 28 in order to ensure that they'll seat more easily on a closed bolt.)

quote:

Originally posted by RogueJSK:
That's not normal for a PMAG.

Bears repeating. I regularly load my PMAGs with 30 rounds and have experienced no problems.

And I have had magazines turned in to me with 31 rounds stuffed in despite the previous users’ having been cautioned otherwise; your problem is exactly what can result. “No good deed …” (by a manufacturer) and all that.

quote:

Originally posted by 1flynDO:
Why do some work in a rifle and some don’t? I have gen 2s that won’t seat on a closed bolt without getting slapped hard. Range mags for sure.

Sounds like they might be overloaded or you might be employing poor technique

It can very by weapon. Some load Pmags to 28 or 29. A decent pop on the bottom of the mag to insure proper seat is a good idea imho. I am not bashing them. I just do not think using some force to seat them is indicative of a problem.

quote:

Originally posted by old rugged cross:
It can very by weapon. Some load Pmags to 28 or 29. A decent pop on the bottom of the mag to insure proper seat is a good idea imho. I am not bashing them. I just do not think using some force to seat them is indicative of a problem.

I agree. I've had the same Pmag fully loaded seat easily in one AR but required a good whack on the bottom to latch on in another.

I agree that pmags will normally tolerate seating on a closed bolt with 30 rounds loaded. It works fine on on my personal guns. However, we recently acquired some Sig M400s for work, and you can't seat a PMAG with 30 rounds loaded under a closed bolt on those guns no matter how hard you try. I tried pushing, pulling, smacking, all kinds of stuff. I'm not sure what Sig did, but those guns just will not tolerate it, even though it works fine on every other AR I own, and all of our DRMO FN M16s. I just reiterated to the guys that they need to download their mags by two, and when they did that, the issues stopped.

Yep, 28 rounds max.

Been doing the 28 round deal for a long time. It always seems to make all reloads more smooth and consistent no matter what AR or magazine combo your running.

When I was in the Army, we downloaded our magazines by 2 but I've gotten away from that for a long time now and loading 30 works well with all 3 ARs I've got.

I have seen experienced shooters make an error loading mags and put 31 in a PMAG and it won't seat on a closed bolt.

I typically load to 30 but it is purely personal preference. I am accustomed to it and it is normal procedure for me to give a magazine a healthy smack as I set it into position.


I have fired tens of thousands of rounds out of PMAGS. I recall ONE magazine induced stoppage, a double feed.

That mag is marked. I still use it for training. It has never happened again.


I prefer PMAGs to USGI but I don't sweat it and would use either.

Just repeating a comment above. I don't think I see the actual gun type listed. And there are a bunch of Gen 2 Pmag issues on some guns that take ar type mags but aren't ar's like Scar, Bren etc...

quote:

Originally posted by hrcjon:
Just repeating a comment above. I don't think I see the actual gun type listed. And there are a bunch of Gen 2 Pmag issues on some guns that take ar type mags but aren't ar's like Scar, Bren etc...

My case, just the everyday AR-15s.

IN theory, a properly loaded Gen2 pmag should load in an AR. It may take a bit of a whack to deal with various dimensional issues but unlikely to be really big issue or require real force.
But you can tap, bash, whack or whatever on some of the other guns that take an AR mag in principle and you aren't going to get anywhere with a Gen2pmag.

If you slap that magazine hard enough on a closed bolt, I imagine you will dent that top round. If you're inserting that mag on a closed bolt, that means you've probably got one in the chamber, which means you won't be manually loading that damaged top round- you'll be relying on the rifle to feed and extract that dented case. You're probably be alright, but all this can be avoided with a maximum loading of 28 rounds.

Last week I ran a class for a couple of guys and the discussion of 28 or 30 in a magazine came up.

I stated that I always run 28 (for the reason of seating a loaded magazine on a closed bolt). I further stated that in my personal experience, it did not matter if it was USGI aluminum or MagPul Pmags (those are the two types of magazines I own and use), I had difficulty seating the magazine if it was loaded with 30 rounds. One of the students politely said that Gen3 Pmags did not exhibit this issue. For the record, I do not own any Gen 3 Pmags, so I was skeptical.

The student gave me two, fully loaded Gen 3 Pmags and let me run tactical reloads on my carbine. Sure enough, he was 100% correct; no issue seating on a closed bolt.

In spite of this, I will continue to only run 28 because:

1) I don't have any Gen 3 Pmags

2) If I have to load a 'pick-up'/scavenge magazine, I don't have to see what brand or generation it is. I know most magazines loaded with 28 will seat on a closed bolt without issues.

TLDR:

Some fully loaded magazines will seat on a closed bolt. It is up to you to decide what your personal SOP will be concerning what magazines you will own and how you load them.

I've got a ton of Pmags. Pretty even mix of Gen 2 and Gen 3. They all run fine and lock into the mag wells of all of my ARs while loaded to 30. They're pretty much all I buy unless I find Okay magazines on sale for dirt cheap.

USGI like Okay brand I usually download to 28. That's as much to slightly ease the pressure on the feed lips for storage as it is to make them easier to seat.

28 rounds. No more. Sorry for the late response.

This is a colt factory 6933 from 2012. No modifications to the rifle. I vigorously insert the mag on a closed bolt won’t go. This is with 4-5 gen 2 p mags. On an open bolt no problem.