Something odd while shooting my AR this weekend.

[XTAV750]

So this weekend I brought a friend of mine to the range who was in town for the day on business. We brought the AR and loaded up the 30 round mags. I usually only put 20 in at a time, but this time we filled them up. Here's what was weird, with the bolt open the magazine locked right in but with the bolt closed, they wouldn't stay in. I then loaded a mag with 10 rounds and closed the bolt and it held in fine. Otherwise it functioned normally. Has anyone seen this issue before?

 

[economist]

So this weekend I brought a friend of mine to the range who was in town for the day on business. We brought the AR and loaded up the 30 round mags. I usually only put 20 in at a time, but this time we filled them up. Here's what was weird, with the bolt open the magazine locked right in but with the bolt closed, they wouldn't stay in. I then loaded a mag with 10 rounds and closed the bolt and it held in fine. Otherwise it functioned normally. Has anyone seen this issue before?

That's fairly normal.

 

[zerodown]

So this weekend I brought a friend of mine to the range who was in town for the day on business. We brought the AR and loaded up the 30 round mags. I usually only put 20 in at a time, but this time we filled them up. Here's what was weird, with the bolt open the magazine locked right in but with the bolt closed, they wouldn't stay in. I then loaded a mag with 10 rounds and closed the bolt and it held in fine. Otherwise it functioned normally. Has anyone seen this issue before?

Yep. Happens on a number of mags I have. I usually only load to 28/29 and they work fine.

 

[stinx]

There is no give for the spring when they are loaded up. you really have to push them in hard. This is one of the reasons people will only load 28 in a standard military 30 round mag. By loading 2 less rounds you allow room for the rounds to compress down. when the bolts locked open its no compressing down on the rounds in the mag.
you can see this buy loading a 30 rounder to capcity and then pushing down on the top rounds-there will be little room for them to move down. load the same mag with 28 and push down and you will see there is more room for movement.

 

[TomH]

It's not just you, 30 rnd mags have a terrible design flaw.

 

[swampy]

My kid is a Marine. When I bought my AR two years ago I waited for him to come home before I took it out. First thing he did was tell me to leave every mag one round short. He said they do this to prevent problems swapping mags with a closed bolt.

I don't have any 30 rounders to try but my 20 rounders will all slam home with 20 in and the bolt closed.

 

[XTAV750]

See, thats why I come here. Thanks guys.

 

[P-14]

With 30 rounds in a mag you have to insert it with force when the bolt is closed to get it to lock in. I keep 29 in mine - just like AK mags.

 

[drgrant]

It's not just you, 30 rnd mags have a terrible design flaw.

Then why have I never had this problem with 30 round mags from 3 different manufacturers? If you can't use 30 round mags to capacity, your mags are broken or something is wrong with your gun.

I'd say in the OP's case "something screwy is going on", or he's just not hitting the mag hard enough when seating it.

I've never believed in this "28 round download" crap, it's simply not necessary. The "worst" thing that happens is a loaded 30 takes a little more elbow grease to seat if the bolt is closed.

ETA: Maybe I'm just biased because my AR has generally always worked right. The whole time I've had the rifle I only have ever had one mag issue, and that was with an extremely low quality 20 round mag. I threw it downrange and shot it, and then I took its counterpart and did the same thing. No more mag problems.

-Mike

 

[TomH]

Then why have I never had this problem with 30 round mags from 3 different manufacturers? If you can't use 30 round mags to capacity, your mags are broken or something is wrong with your gun.

I'd say in the OP's case "something screwy is going on", or he's just not hitting the mag hard enough when seating it.

I would say you're in the minority, because many others have had issues. My 30 rounders are CProducts brand I believe, and seem to be of good quality. Yes you can get a full magazine in, but I have found you can't really "slap" it in, you have to insert it then push it up hard until you hear the click. If you didn't quite make it, the magazine will fall out when you go to cycle the bolt. I have 2 high quality ARs and they both act this way. I have straight and curved 20 rounders that perform much better. Now I have heard that Pmags may not have this issue but I don't own any myself.

 

[drgrant]

I would say you're in the minority, because many others have had issues. My 30 rounders are CProducts brand I believe, and seem to be of good quality. Yes you can get a full magazine in, but I have found you can't really "slap" it in, you have to insert it then push it up hard until you hear the click. If you didn't quite make it, the magazine will fall out when you go to cycle the bolt. I have 2 high quality ARs and they both act this way. I have straight and curved 20 rounders that perform much better. Now I have heard that Pmags may not have this issue but I don't own any myself.

Another thing I should have mentioned is none of my mags have USGI followers in them. They all have magpul anti tilts in them, so maybe that has something to do with it.... I've never had a lick of trouble, though. They just work. Some are Okay industries, One is a Colt I think, and most of the others are some mystery brand that was USGI style but no markings whatsoever on the body or floorplates.

-Mike

 

[wolf223]

all my 30 rounders are -1

thats what the grunts taught me

my 20 rounders i use at the range and they are well worn.. so i dont have problems with those...

 

[Warrior102]

I'll also toss my hat in for load up and remove one, or at least check to see it the magazine will lock with a closed bolt very important on your zombie preps.

 

[vellnueve]

Give the bottom of the mag a good slap after you insert it.

 

[Fixxah]

I guess I am lucky. My mags are always full and I have never had that problem. Can't say I have been looking for it though.

 

[Admin]

I've never believed in this "28 round download" crap, it's simply not necessary. The "worst" thing that happens is a loaded 30 takes a little more elbow grease to seat if the bolt is closed.

-Mike

You wouldn't say that if you were taking incoming fire while you're trying to top off your weapon to return fire as fast as you can. If you're going to sit on a bench and plink all day load to mag capacity to your heart's content.

 

[Lamina]

You wouldn't say that if you were taking incoming fire while you're trying to top off your weapon to return fire as fast as you can. If you're going to sit on a bench and plink all day load to mag capacity to your heart's content.

This. My weapon needs to work the way it way intended without having to apply "a little more elbow grease" during normal operations.

 

[one-eyed Jack]

I have some 5 round hunting mags for the AR in 6.8 spc. They won't lock in fully loaded with the bolt closed to limit the gun to 5 round capacity to comply with the hunting regs in a lot of states. Jack.

 

[drgrant]

You wouldn't say that if you were taking incoming fire while you're trying to top off your weapon to return fire as fast as you can. If you're going to sit on a bench and plink all day load to mag capacity to your heart's content.

Point taken, I guess I just never found it that much more difficult, but if you're getting shot at, then it's likely that everything is more difficult and every little bit helps.

-Mike

 

[JRyan]

I've never noticed this. I'll have to pay attention next time I'm at the range.

 

[ochmude]

Point taken, I guess I just never found it that much more difficult, but if you're getting shot at, then it's likely that everything is more difficult and every little bit helps.

-Mike

Also gotta keep in mind that if you're being shot at, you may have already been hit. A little more elbow grease might be tough to muster up when you're slipping into shock. The best option would be to have the military switch completely to unsucky mags, but until that happens downloading by a couple rounds is cheap insurance for reliable seating.

 

[EddieCoyle]

I've never noticed the problem, but then again, I'm in the habit of just forcing everything.

 

[45collector]

Like Mike, I use only Magpul anti-tilts in my AR mags. They are mostly Center Industries, OKAY, and a couple Colts. Never had a problem inserting a full 30 in with the bolt closed.