Jams needs to be filed down to - Duramag SS AR-15 .458 SOCOM/.50 Beowulf 10 Round Rifle Magazine

Haven’t shot it yet because I need to file down a half moon shape so that it can load the bullets. Failure to feed out the gate has me very upset. I bought these mags so I didn’t have to do any mods to it but you do. Using underwood ammo (extreme penetration & hollow points) tromix bolt on bear creek 458 upper.