Ar-15/M16 Billet Upper Receiver, .458 Socom

Enlarged Ejection Port Accommodates .458 SOCOM

Stripped billet upper drops onto standard lower and features expanded ejection port that accommodates .458 SOCOM and other big-bore AR-15 calibers. Integral Picatinny rail provides mounting space, and slick-side design does not require forward assist or ejection port cover, simplifying the build. Has M4 feed ramps, and accepts standard bolt carrier, charging handle and barrel nut, sold separately.