"As others stated mash do stretch at the seams. Not a really big deal, just wrapped some duct tape around them. Problem solved. Mash feed flawlessly, after the duct tape they re pretty solid. I've dropped a mag down some stairs (accident) still worked perfect.
4 stars for the seams though.
"Probably some of the worst midcaps. I tried to love them, I truly did, but these mags are pretty bad. I've ran them through a JG SG 550. JG 552, and an ICS 551. These mags do good with .2s, but forget using anything heavier. Can even load .25's in them without them struggling horribly to feed. You have to smack and tip them upside down for the spring to even move up. They fed flawlessly with .2s, but for a DMR build these are some of the worst. Seams at the top bulge when loading, and 2 mags have completely split and I had to super glue them all along their seams as if you would super glue a severe paper cut. (I have 6, and 2 from 2 different boxes had the issue, and all 6 had trouble feeding .28s, more so than others.) The plastic is a nice mold, but needs stronger seam glue. Another gripe I have with these is that you can't disassemble them completely for cleaning. You can only take out the spring. (Cleaned the spring and even put some silicone in the Mags and they still dont feed good. 3 of the 6 at least feed, but very slowly and not enough to keep up with a 9.6v on full auto. (Usually feed on semi, that is, if you get the good mags.) Horrible Quality control.
Good feeding with .2s,
Great capacity (if you can get that many in them)
Easy modification to fit ICS that doesn't effect internal performance
Won't feed anything above .2s without MAJOR issues
Can't disassemble for cleaning
Breaks speed loaders (rare)
Picky with BBs. (Only feeds good with certain brands) *I only run G&G, Matrix, Goldenball, valken.
Overall a 2/5. I loved these midcaps until recently. The recent 2 pack is horrible, and these mags have a very low tolerance. If you think it's worth the risk, or you only use these for CQB, then go for it. If you're a field gamer like me, be wary.