Keith P. from United States, CA Public Profile

I was skeptical about internet claims that these mags are the best ever for reliable 300 blackout feeding, until I tried them.

The problem with 300 BLK subsonic is that the larger ogive (bullet shoulder) rubs against the interior positioning ribs on standard mil spec 5.56 NATO style mags. This causes binding as the cartridges rise in the magazine, which produces "nose diving" and failures to feed.

Lancer mags don't use those ribs at the bullet shoulder, so cartridges move freely and snap right up as bullets are fed every time. They mags also use very forceful springs that give a stronger push on rounds for more reliable feeding.

This is true for both their standard 5.56 mags, as well as the ones designated for 300 BLK. 220 grain subsonic ammo feeds perfectly with either one. Other than the cosmetic "300" on the outside of the mag, different color follower, and the FDE colored baseplate, they appear identical to me and function exactly the same.

I'd recommend these on reliability alone, but they also look terrific, feel like premium products (no rough edges anywhere), and add a little more function with the see-through bodies that show your remaining rounds.

Don't know if they will survive a drop from a 3 story building. But that's not a concern for me. I'll let someone else drive over one with their truck to test durability. They're tough enough for use home defense, range, or hunting. If you're an operator, you probably just grind down the ribs in your STANAG mags. But

This is essentially identical to the standard 25-round magazine, with two differences: There is a small metal roll pin inside limiting capacity to 10 rounds, and there is no sliding button assist. These are available from aftermarket vendors, but require some modding, as the pin prevents the follower from being positioned to install the button. To install an aftermarket button slider, the roll pin can be removed with a few heavy sledgehammer hits with a screwdriver, but doing this will of course convert the magazine into a 25-round capacity magazine.

If you live in a state with a 10 round limit, this could be a problem. And if you live in a free state, you probably just want to buy the 25 round magazine instead.