Does not include Tromix center feed follower.
This is a complete AR-15 Lancer 10rd 5.56 magazine (body, spring, 5.56 follower, base plate) which has the front leading edge remachined to allow large diameter cartridges to strip out without striking the front end. The Tromix aluminum center feed followers are sold separately and can be installed in this magazine after you remove the plastic 5.56 follower.
This magazine will hold 4 rounds of .458 SOCOM or 450 Bushmaster ammunition. It’s a 4+0 situation in .458 SOCOM and a 4+1 in 450 Bushmaster.
Note: If the Tromix center feed follower is installed in this 4 round magazine, it will reduce the capacity to 3 rounds of 458 SOCOM ammunition (3+1), or 4+0 rounds of 450 Bushmaster ammo.
However, the Lancer floor plate retainer contains a 1/2″ long travel limiter stop, and if removed, will bring the capacity to (4+0) in 458 SOCOM and 4+1 in 450 Bushmaster, with the Tromix follower installed.
Keep in mind, if this modification is made, when the standard 5.56 follower is reinstalled, your magazine will now hold 12 rounds of 5.56 ammo.
These magazines are only for use in rifles that accept AR-15 magazines.