
Mine worked just as expected, it loads reasonably easily to the full 60 shot capacity. It slips into and out of the magazine well very nicely on the carbine I grabbed (it happened to be a DPMS lower receiver). The 60 shot Surefire magazine fed the 60 rounds of M193 ammunition without a hitch of any kind and held the bolt/carrier open after the last round fired.
Yup, mine was a very brief function test, but I feel that the magazine will perform as expected next time also. I still think that they are more expensive than they should be, but a guy really needs a new toy now and then.