M-16/AR-15 magazine questions -

12 September 2003, 04:27

Jerry Kraus

Who sells or makes the most reliable 30 round mags for a AR? I have recently purchaed a few new ones from Cabella's and Midway = 1 out of 3 functions properly. I have seen mags that were "swelled" so you had to force them in & out of the magazine well, I have seen them fail to feed reiably, and even one where the last round pops out on its own before the bolt carrier can grab it so it jams on the chamber! Second question- in 20 rnd mags the military puts ony 16 rnds in them to save the springs, what is the practical capacity for a 30 rounder, anyine know?

12 September 2003, 04:48

475Guy

Seems that you bought commercial mags. The ticket is to buy milspec mags still in wrapping. The thing that everyone does is to replace the springs and followers on a regular basis (about every 1-2 thousand rds or less) [Cool]

12 September 2003, 05:22

BECoole

quote:
Originally posted by Jerry Kraus:
Who sells or makes the most reliable 30 round mags for a AR?

Buy only USGI or British magazines. I like to get them at gunshows.

quote:

Second question- in 20 rnd mags the military puts ony 16 rnds in them to save the springs, what is the practical capacity for a 30 rounder, anyine know?

Used to be some military guys would only put 18 or 19 rounds in a 20 rounder, not to save the spring, but to insure reliable feeding. Sometimes that 20th round is in there a little tight. Stricktly a personal preference thing.
The practical capacity of 30 rounders is 30 rounds. I've never had jams due to fully loading one.
Springs wear out not from compression, but from cycling. Loading and unloading a magazine will put far more wear on the springs than simply keeping it loaded once. I've heard many stories of magazines loaded for 1/2 century or more and still functioning fine. My Dad had one loaded from 1945 until I shot it empty in about 1985. Works fine.
Bottom line: If you don't want your mag springs to wear out, don't use them.

12 September 2003, 05:39

eshell

quote:
Originally posted by 475Guy:
Seems that you bought commercial mags. . .

Seems so. Commercial magazines have a terrible reputation and are normally built like crap. As far as I know, there are NO decent mags made by commercial companies.

quote:
. . . The ticket is to buy milspec mags still in wrapping. . . .

I agree. Stay with USGI. New ones are obviously the most desirable, but also the most expensive. I have plenty with the finish completely worn off that work fine in two rifles.

quote:
. . .The thing that everyone does is to replace the springs and followers on a regular basis (about every 1-2 thousand rds or less) . .

IMO, the only reason to replace the follower would be to upgrade an old style follower with the new (green) style. The older followers would tip forward occasionally when loaded and get stuck enough not feed. The new, green followers have an extended leg to help keep it aligned inside the box.

Springs should be replaced on occasion, but I have some that are literally twenty years old and are fine. I also have a bunch of new replacement springs standing by, that I bought when I thought they needed replacemnent more often.

The last round or two in a twenty is very tight. If fully loaded, it can be difficult for the rifle to strip the top round and it sometimes jams. Company SOP, we were told to put only eighteen in our twenties. For playing around (99.9% of my AR15 activity), I fully load them and haven't had a problem. For serious purposes, I would take every precaution I could to ensure reliability, including leaving a couple rounds out. I actually prefer the 20's to the 30's for convenience and comfort. 30's just stick out too much. Far as I know, there has never been a problem loading 30's to full capacity.

12 September 2003, 13:03

475Guy

On the 20 rd mags, spring compression and fatigue is not as critical as in the 30 rd mags. Same dif as single stack vs double stack mags in handguns. I've shot literally 300,000 rds in my mags over 30 yrs and have found that 30 rd mags DO AND WILL HAVE SPRING FATIGUE because of the extra 10 rds. Do what you gotta do but remember that originally the COLT M-16 mags were THROWAWAYS. That's why they made them out of aluminum. [Cool]

12 September 2003, 14:11

tincan

quote:
Originally posted by Jerry Kraus:
in 20 rnd mags the military puts ony 16 rnds in them to save the springs, what is the practical capacity for a 30 rounder, anyine know?

I have a pal who was a "riverine warfare" navy guy in the viet nam war, he told me they never loaded more than 17 rounds in their 20 round mags after I described having trouble using fully loaded mini 14 mags. i found dropping the max capacity by three rounds solved my problems on any hi-cap magazine.

-tincan

ps- also, to the poster who wrote that 20 round M16 mags were throwaways- if that's the case, why would they make them out of a material more expensive than steel?

-not a challenge, it just popped into my mind while I read your post.

thanks,
-tincan

12 September 2003, 14:22

Duckear

Buy USGI mags. Thermolds are OK, but I would stick with GI. Plenty for sale at AR15.com. Wouldn't worry about replacing springs, since most folks with AR's seem to have 6+ mags per rifle and you can get used, decent ones for under $20 a piece. If you start to have malfunctions, then replace springs with Wolfe. I'll bet more people ding up the feed lips before they wear out the spring.

If you really want, I have a couple of NIW USGI Labelle 30 rd mags I'll sell for $30 each plus shipping. Shoot me a PM if interested.

[ 09-12-2003, 05:24: Message edited by: Duckear ]