AR-15 Magazine load question

[ArcadiaGP]

Is it common for a full-magazine of 30 to not push in far enough to "lock"?

One recent example, I loaded 30 into a mag... put one in the chamber... took out mag, loaded one more to top it off, and tried to put the magazine back into the gun. It wouldn't go high enough to "snap" into place.

Are AR's not meant to be 30+1?

 

[bstewrat3]

Will it take a 30 round magazine with the bolt forward and no round in the chamber? Trying to top off could effect function as well. I have had more issues with feeding on the first round out of a full 30 round mag than any other time. It is due to the amount of pressure the spring is exerting on the top round on the feed lips of the mag.

 

[indyjohn]

What you're describing is common. I am not aware of a solution to get you to 30+1.

 

[rvb]

Short answer, this is why most load to 28. Very hard to get most mags to seat on a closed bolt. Some mags will let you get 30 in and seat on a closed bolt, but common practice is to load to 28.

-rvb

 

[Leo]

Short answer, this is why most load to 28. Very hard to get most mags to seat on a closed bolt. Some mags will let you get 30 in and seat on a closed bolt, but common practice is to load to 28.

-rvb

+1

The new follower designs seem prone to this. I have some old beat up ones (that sometimes jam up) that usually hold 30 ok, but the newer ones act like the op describes(but never malfunction when loaded with 28).

 

[ArcadiaGP]

Very good to know, thank you. Wanted to make sure it wasn't an issue with my AR or mags.

 

[N8RV]

I've read this elsewhere. Load to 28, not 30.

OK, I understand the reason why. Same thing with many pistols, too.

But why 28 and not 29?

 

[PapaScout]

One of my PMags is loose enough to load 31 rounds and then won't lock in place.

 

[rvb]

But why 28 and not 29?

Several reasons, none significant.

1) Inertia. It's what's commonly taught. down by 2 was started in combat w/ the 20 rounders when the M16 was still pretty new.

2) some guys are big on the top round always being on the same side. (Top round on right goes back to the M1, at least) The idea that instead of doing a press check you load the rifle, pull the mag and verify the top round has moved to the other side, then re-seat the mag. Not a bad theory. Newest GI mag followers have the top round on the opposite side for some reason, so you have to REALLY know your gear to rely on this.

3) On some gun/mag combos it may be slightly easier yet to insert w/ 28 vs 29.

-rvb

 

[rvb]

One of my PMags is loose enough to load 31 rounds and then won't lock in place.

PMAGs have a little more room and will generally let you seat them easily w/ 30 on a closed bolt, and sometimes can often take 31 rounds. If you're just loading loose rounds (not off a stripper clip), this is why it could still be considered a good idea to back off one or two from full to make sure you don't have more than 30, even w/ PMAGs.

I'm partial to Aluminum GI mags, and I like to use stripper clips. I don't have to count higher than 3 that way, and my simpleton brain can handle that... 3 stripper clips w/ 2 rounds removed from the 3rd clip before loading it.

W/ experience, you can get an idea if a mag has the desired # of rounds loaded by pressing down on the ammo till it bottoms out, and seeing how much room is left.

-rvb

 

[UncleMike]

I've always loaded my AR mags to full capacity and never had one fail to lock into place with the bolt closed.
This is with multiple AR's and lots of mags.
Well made mags have enough slack to allow full charges and still lock into the mag well.
The old wives tale about loading two rounds shy started in Viet Nam.
Back then the troops reloaded their mags numerous times and eventually the springs lost their ability to return to full length.
The constant flexing of the springs weakened them due to metal fatigue.
Leaving the mag fully loaded, or unloaded, will have zero effect on the spring.
I have mags that I loaded full in 1974 and I take at least one out every year to test the springs.
Not one has ever failed to function properly.

 

[rvb]

I've always loaded my AR mags to full capacity and never had one fail to lock into place with the bolt closed.
This is with multiple AR's and lots of mags.
Well made mags have enough slack to allow full charges and still lock into the mag well.
The old wives tale about loading two rounds shy started in Viet Nam.
Back then the troops reloaded their mags numerous times and eventually the springs lost their ability to return to full length.
The constant flexing of the springs weakened them due to metal fatigue.
Leaving the mag fully loaded, or unloaded, will have zero effect on the spring.
I have mags that I loaded full in 1974 and I take at least one out every year to test the springs.
Not one has ever failed to function properly.

If you're combo of gun and mags lets you seat the mags easy enough, do what makes you happy. I CAN force most of my mags to seat on 30, but not when keeping the weapon up on target w/ my strong hand and doing a speed reload, or reloading while on my side shooting under something... there's a good chance I won't seat it solidly and I'll be picking it out of the dirt. The tollerances on the OP's gear aren't letting his mags seat. It's a pretty common issue and far from an old wive's tale.

Some thoughts from LAV:
Magazines

2.) On tough to seat mags, download at least 1 round.
If a fully loaded mag is difficult to seat with the slide or bolt assembly in battery then download the mag by at least 1 round as a matter of habit. USGI aluminum M16 magazines are a good example of this as they are really only properly designed to take 28 rounds, not 30 as advertised

I don't think it's a spring longevity issue. I think it's primarily an effort/time to reload issue. It could also [potentially] be considered a reliability issue from the increased drag on the carrier with very tight mags.

-rvb

 

[ArcadiaGP]

Makes sense. The AR and mags are never used, so they haven't had any time to loosen up.

 

[Excalibur]

Get one of these

[ame]http://www.youtube.com/watch?v=2l6wlbjKi_c[/ame]

 

[esrice]

rvb is on it.