Home Forums Hunting & Shooting AR and Tactical Rifles Lets talk about AR mags

A couple of friends have me pondering.

One is a former SF col whose mos was small arms. He tells me he's seen feed lips on aluminum mags distort when left fully loaded for a long period under compat conditions. He always underloaded his mags by a few rounds. SF types are now using steel SIG mags. Recently we ordered the fairly new Sig polymer mags that have a built in coupler, $30 for two. HAven't got to the range with them yet.

Friend two is a former GI, personal defence advocate and a savant when it comes to military firearms. The guy prolly has a hundred of every brand of mag out there. He swears Lancer polymer mags are the only thing to buy.

So, heres the questions. Anyone keep or had probs with keeping mags fully loaded long term ? What are the thoughts on polymer vs aluminum vs steel.

I know some of you are serious competitors what do you prefer?

O

I always download GI mags by 2 and have carried it over to Pmags. Never had any problems. My 30rd GI mags have magpul followers in them, 20's I changed all to the old alloy followers.

Never heard of the Sig mags in use but HK mags were/are in use, not nearly as trouble free as most would have yo to believe according to credible reports I've seen. Disclaimer; I've never done more than looked at HK's mags and they might be the best thing since sliced bread but I have no reason to change from USGI mags with Magpul followers.

I use Brownell's 20 rd mags, keep them full and haven't had a problem.

I have used Magpul AR mags since 2007. That includes 12 months in the desert. I had a few HK mags. Heavy, awesome, and heavy.. (also very expensive.)

I still have my original Magpul mags, and have since added some troy Battle Mags. I like the Troy option right now.. their profile is more similar to the steel mags I 'grew up' with.

Polymer has come a long way. Unless you are doing more Combat sheite than I did; They'll work just fine.. and they're cheap!

SIG doesn't even use the SIG mags anymore. Their guns come with New Haven mags.

P-mags are at the top of the AR mag food chain for now IMO. Load 'em up, snap the covers on, which take the tension off the feedlips, and forget about any issues. They just flat don't have any.

I also have some of the Troy Industries polymer mags, still looking at them, i.e. leaving them loaded for long periods of time, checking feeding, that kind of stuff. So far, so good, and unlike the P-mags, they stack flat.

Please don't continue to spread this nonsense.

With USGI mags, load 30 rounds in the magazine and forget about it until time to use it.

+1
Had a couple that were loaded for over 4 years when I finally found them back in the garage. Refilled them with new ammo and they have worked without a hiccup

In our infantry trophy team practice with GI 30s, we've found that as far as stripping the first round out of the mag cleanly, without a jam, we were 100% with 28 rounds in the mag. 29 or 30, we'd have a feeding issue now and then. Enough so not to risk it. Plus whats 1-2 more rounds gonna do anyway, you eitehr got more mags or you don't.

I don't care for 30s though, they don't allow nice prone so I run all GI 20s...keep 18 in them.... Some have been loaded for over 10 years before we shoot that ammo out and put new in...

+1 Well put.

What are you talking about? I wasn't bagging on USGI mags, as I'm pretty sure my post didn't say anything about them, so I don't see what nonsense I was spreading.

The cap that takes the tension of the polymer lips of the P-mag is a good thing.

Whether the USGI mags are superior to the P-mag is a whole other argument.

As with any semi auto,mags are important...Here is a review on a certain AR and the only failure was traced to the magazine used.

Reliability: * * * * *
One feeding issue�traced to the cheap aluminum magazine I was using as a back-up. Not a single failure with the factory-issue Magpul. I shot well over 1000 rounds through the rifle without cleaning (with additional lubrication)

Jayco

Interesting stuff. I've kept a couple of fully loaded USGI mags in my safe-just in case-for years. Personally, never had a problem with any mag in an AR.

But one wonders why SF types prefer those $50 steel mags.

O

Because they aren't buying them. And 'prefer' is relative..

Well, you load up a plate carrier with eight H&K mags and a pair of ESAPI plates and you might cease to be a fan.

Most guys I see are running P-mags.

I was under the impression that 28 rounds in a 30 round mag was to allow easier seating on a closed bolt. That might be an issue in combat that could have meaning. For me, I am not anticipating combat anytime soon, but I do load the Pmags to 28.

Under loading AR mags goes back to Nam. Maybe its just tradition/superstition/habit or a smart thing to do. Habits die hard. Bought an M1A a few years back, loaded the mag and strarted to tap it against my helment. Yep, wasn't wearing one.
O

Pops was a grunt in Nam 68-69. He had 20rd mags and loaded 19. He also never had a jam but kept his rifle clean which wasn't that common from what I understand. Interesting thing too, seldom used full auto.

If you can't get it done with 28rds likely 2 more are not going to help your situation anyway

2 out of 3 of my 20 rd. pmags function fine 100% of the time.
1 does not like to be cold. It jams like the anti-tilt isn't doing its job. Probably put 500 rounds through them over 5 occasions. I still bought a couple more.

Lancer L5 mags function all the time/everytime. I haven't used their Advanced Warfighter model much.

I'm not buying any more pmags. Lancer all the way. And all I do is shoot prairie dogs and paper.

Thought I'd pass this link along as more reasons to buy Lancer. I'm not affiliated with the blog, Lancer or Magpul.

Lancer AWM review

-S

There can be quite a bit of variance in USGI mags due to manufacturing tolerances and there are so many different manufacturers over the years. I have seen USGI mags that would hold anywhere from 29 to 31 rounds. There can also be a variance in how high the mags fit in the gun, due to differences in the guns and mags.

As stated before some mags if fully loaded will not reliably feed the first
round.

Some mags if fully loaded will not seat on a closed bolt.

For those 2 reasons we always loaded all magazines in the team to 28 rounds. That way they would all work in everyones gun all the time when we had to start sharing mags.

I've seen more than one person learn this lesson the hard way.

What is acceptable on the range is not necessarily acceptable down range.

As far as Pmags go I have had mixed results. Most run great and I load them to 30 rounds but I have a few that have developed cracks near the rear of the feed lips.