I bought two of the 20 round .308 Magpul mags for my DPMS LR308 as soon as they were released thinking I was getting the best. When the bolt is pulled back on an empty mag the bolt "hold open" tab pops up before the bolt is all the way back and it jams. You can't open or close it without removing the mag and using a screwdriver to pry the tab down. The factory mags work perfectly. I talked to Magpul who blamed DPMS; I talked to DPMS and they blamed Magpul. I returned the two mags for two more of the same; same problem. I returned them for a refund, and order two more a few months later; same problem. Factory mags work, Magpul mags don't. I've never fired it with the Magpul mags because I'm afraid of what might happen when the last round is fired and the bolt goes back on an empty Magpul mag under power. These should be good mags, but for a DPMS LR308 they aren't.
I have two, and just ordered two more. I've had zero issues. They feature the typical Magpul fit and quality. Don't hesitate on these, as they're a very good value.
As stated in the ad, they're SR 25 type mags, and work great in the DPMS, CMMG, Bushmaster LR series etc. You'll need the Armalite type for an Armalite .308 or variants.
Very nice mag, works great in my S&W M&P 15 Sport. The 20 round version works great off the bench, the 30 rounder is a little too long to use with a rest and sand bags, but the 20 round is just right. I also like the dust cover that enables you to keep the magazine loaded without putting pressure on the feed lips of the magazine. Very nice, I will probably pick up a few more when I find a deal on some.