18"-20" SPR 308 Upper Assemblies

18"-20" SPR 308 Upper Assemblies

Shop .308 18–20" AR-10 upper assemblies at Moriarti Armaments for SPR, precision, hunting, and longer-range configurations. Browse 18-inch and 20-inch .308 Winchester uppers with available M-LOK and rail systems, barrel profiles, muzzle devices, and custom finishes. These mid-to-long barrel configurations provide additional velocity potential compared with shorter .308 platforms while maintaining the versatility of a semi-automatic large-frame AR. Compare uppers by barrel length, gas system, twist rate, handguard, barrel profile, finish, and included components.

Is an 18-inch or 20-inch barrel better for a .308 AR-10?

Both 18-inch and 20-inch .308 AR-10 barrels are popular for precision, hunting, and longer-range applications. An 18-inch barrel offers a balance between overall length, weight, and ballistic performance, while a 20-inch barrel can provide additional muzzle velocity with some .308 Winchester loads. The better choice depends on ammunition, intended shooting distance, rifle weight, maneuverability, and application rather than barrel length alone.