.358 Upper Assembly | Custom .358 AR-10 Uppers | Moriarti Armaments

.358 Upper Assembly | Custom .358 AR-10 Uppers

Shop .358 Winchester AR-10 upper assemblies at Moriarti Armaments for compatible large-frame AR platforms. The .358 Winchester uses a .358-inch projectile and is based on the .308 Winchester case family, offering a larger-bore option for hunters and shooters interested in heavy projectiles. Browse .358 AR-10 uppers in available barrel lengths, handguards, muzzle configurations, and finishes. Compare assemblies by barrel length, twist rate, gas system, receiver pattern, components, and included parts.

What is the difference between .358 Winchester and .308 Winchester?

.358 Winchester and .308 Winchester share the same parent-case family but use different bullet diameters. The .358 Winchester uses approximately .358-inch bullets, while .308 Winchester uses .308-inch bullets. The larger projectile gives .358 Winchester a different ballistic and hunting profile, particularly with heavier bullets. On compatible large-frame AR platforms, some components may be shared, but the correct .358 Winchester barrel, ammunition, and caliber-compatible components are required.