Older version? Tight fit, solid build
The 20 round green follower design I received (ordered 2) both were very well constructed, with a very tight fit. They will take the full 20 rounds, & can still be inserted on a closed bolt. They do require more force to insert into my WW AR-10 than a typical AR-15 would, & the magazines I received did not have the witness holes for round count. Overall a good value especially if you prefer steel to polymer and they accept the standard 2.8" COL needed for the 6.5CM. They fed my rifle reliably with 0 FTF's. Overall they are easy to reccomend, & as for the lack of round count witness holes, a drill bit can easily solve that, once you figure out where to put the holes.
Great but with a hitch
This magazines issue isn't the magazines fault, I have an Armalite AR-10A and the magazines are TIGHT in the mag well, as in non-dropfree tight. Again, not the fault of the magazine, just the variation of different rifle manufacturers.
Works fine in my PA-10 gen2
Bought one to give it a go in my newest toy (Palmeto State Armory gen 2 PA-10). So far zero issues, boring like its suppose to be in other words. It drops free and the bolt holds open on last round. Finish is actually rather nice. Who knows how it holds up long term but so far so good. The thing seems solid in a brick like fashion. The only draw back for me is that it is noticeably heavier than say, a 20 round Pmag while at the same time taking up way less vertical space. Bottom line.... Good looking, functional mag that seems tough, while weighing a couple ounces more than the biggest plastic competitor. Ya, I'm buying more for my PA-10.