I'd point everyone to: ar15.com/forums/topic.html?b=3&f=66&t=273312

Trying to find if other people have been having problems with the new mags coming out. Mainly wish to know what date, what follower, and what brand your having problems with. This is the result of my (limited) testing.

Repost
Well, after reading this, just got back from some testing. I wanted to find out what was happening with these mags. Just got the Magpuls about 3 weeks ago, and noticed that I was having problems with the gun failing to cycle properly with a few of the mags I've just bought.

The guns:
Bushmaster 16in Carbine (model# BCWA3F 16)
Colt 6721

Both are stock internals. The Bushmaster has 1230 rounds fired through it before testing (I'm trying to find out what fails and when). The Colt has somewhere in the area of 2800 rounds according to its owner.

Here are the results -

----
2 Colt 30 rounders (Test group)

Green: Cycles manually, cycles when firing, cycles with bolt open (All)

(Both guns no FTC)
----
1 Bushmaster 30 rounder dated 4/05

Magpul: Cycles manually, cycles when firing, cycles with bolt open (All)
Green: Cycles manually, cycles when firing, cycles with bolt open (All)

(Both guns no FTC)
----
5 D&H 30 rounders dated 8/05

Magpul: Cycles manually, cycles when firing, cycles with bolt open (4)
Magupl: Cycles manually, FTC when firing, cycles with bolt open (1)
Green: Cycles manually, cycles when firing, cycles with bolt open (All)

(Colt on the FTC; was repeatable on same magazine)
----
3 D&H 30 rounders dated 11/05

Magpul: Cycles manually, cycles when firing, cycles with bolt open (1)
Magpul: Cycles manually, FTC when firing, cycles with bolt open (1)
Magpul: Cycles Manually, FTC when firing, FTC with bolt open (1)
Green: Cycles manually, cycles when firing, cycles with bolt open (All)*

(Both guns on Magpul FTC when firing; repeatable on same magazine. Bushmaster on the FTC firing and bolt open; repeatable on same magazine.*One FTC with bolt open on the Colt (Green); wasn't repeatable after 3 tries on same magazine.)
----
4 D&H 30 rounders dated 12/05

Magpul: Cycles manually, cycles when firing, cycles with bolt open (3)
Magpul: FTC manually, FTC when firing, FTC with bolt open (1)
Green: Cycles manually, cycles when firing, cycles with bolt open (3)
Green: FTC manually, FTC when firing, FTC with bolt open (1)

(Both guns on the same magazine (with Magpul or Green) had FTC on all 3 parts of test; repeatable.)
----
2 CP 30 rounders bought 12/05

Magpul: Cycles manually, cycles when firing, cycles with bolt open (1)
Magpul: Cycles manually, cycles when firing, FTC with bolt open (1)
Green: Cycles manually, cycles when firing, cycles with bolt open (2)

(Bushmaster with the FTC with bolt open; repeatable.)
---

I'd like to know what everyone else is using: Magpul or Green. Obviously (at least from my pathetic testing) there is some kind of problem with these magazines. I'd like to make a point that though we had problems with the Magpuls, I still trust this product, nor am I condemning it.

bump

I bought a ten pack of D&H blacks around the time you did.  I tested mine this afternoon.  Black teflon D&H 30rd mags with grey Magpul GenII followers shooting Wolf thru a 16" DSA-POF ZM4 GTC and a 14.5" DPMS M4.  Zero problems.  Mine did not have the feed lip issues discussed in the other thread, so I assume some people got a bad batch either just before or just after I ordered mine.


TS

So far it seems hit or miss. Either your mags are perfect, or feed lip problems; and Magpuls exacerbate the problem. No expert, but the Magpuls seem to push the cartridge tighter against the lip than the green (probably wrong about this).

Quoted: So far it seems hit or miss. Either your mags are perfect, or feed lip problems; and Magpuls exacerbate the problem. No expert, but the Magpuls seem to push the cartridge tighter against the lip than the green (probably wrong about this).

I dont think so.  The follower in a doublestack magazine really only does two things... keep pressure even (no tilting) and then hold the last round correctly against the feedlip.

When a mag is loaded with two or more rounds - the rounds will assume the width of the mag body, and doublestack, regardless of the follower.

If the new mags are tighter against the feedlips in pressure - that would be a difference in spring tension.  It is generally regarded that spring tension is a good thing.... as many failures are induced by not enough.  Of course, too much and you wont be able to strip the round from the mag.

Lastly - you have the potential of a burred edge on a feedlip.  This could increase the amount of force necessary to strip the round from the mag.  If the manufacturing process is allowing for too much friction on the feedlip surface due to burrs... this could increase failure rate.

That being said - mine seem to strip and chamber just fine thus far, and if burrs are an issue, those will disappear with use.

Always, always test any magazine that your life may depend on.  I dont care if it is a new D&H/CP, or a 30 year old USGI.

I'm more than willing to concede the point. That said, what led me to think on this is the spring is positioned at a different point with the Magpuls than the green. Also, in testing I saw greater problems with the Magpul in the magazines that weren't "mil-spec".

Anyways, as I said in the other topic, if someone is having problems with cycling, then just SLIGHTLY dremel the burs and the feed lip. After doing this, a magazine that wouldn't cycle properly at all is working flawlessly.