what are the benefits, if any of the different brands and capacity?  why do some seller specify green followers?

thanks

Check out the FAQs at the top of this forum:

http://www.ar15.com/forums/forum.html?b=3&f=17

20 rounders are used for benchwork, for the most part, although some (myself incuded) like the 20s for all round use. 30 rounders are for plinkin, or SHTF work and long term storage.

Stick with USGI mags, and don't buy ANY 20 rounders with greenies installed as they are fine with the alloy followers they came with and reliability suffers when folks mod them w/ non-alloy followers........, only the 30s are generally upgraded with the long tailed followers (either green or the newer orange ones).

Mike

for SHTF work - I have my Vepr with a shitload of polymer 30rd mags.

For target shooting, plinking, and having fun - the AR-15 with 20rd USGI mags are used. I swapped in green followers for the straight mags and they're not as good as the alloy follower namely:

The plastic (black or green) followers lack "tails" at the rear of the follower (the part that hits the mag catch) that prevent it from tilting forward. The alloy followers DO have these tails and you can't tilt them forward.

The Vepr isn't as fun to shoot becuase it's not as accurate, the recoil is stronger, muzzle climb w/o a muzzle brake is a bitch, and its loud and crude. That makes it a great SHTF battle rifle though (engagements under 100yd, great stopping power, ultra reliable - not saying its more/less reliable than a properly maintained AR-15). It's not as fun for me because i have a splitting headache and sore shoulder after about 120 well placed shots. I can burn through 2000 rd at the bench with an AR15 without so much as a headache (but a big adrenaline rush)