.338 ARC Uppers and Parts for AR-15 – Moriarti Arms

High-Energy Subsonic and Supersonic Builds for the Modern AR-15

Shop premium .338 ARC parts, barrels, bolt carrier groups, and complete AR-15 upper assemblies at Moriarti Armaments. Designed to deliver exceptional performance with both subsonic and supersonic ammunition, the .338 ARC combines impressive energy, accuracy, and manageable recoil in a compact AR-15 platform. Our selection includes precision-machined .338 ARC uppers, barrels, and components that are compatible with 6.5 Grendel Type II bolts, making them an excellent choice for custom builds, hunting, recreational shooting, and suppressed applications. Whether you're building a new rifle or upgrading your current platform, Moriarti offers dependable .338 ARC components engineered for reliability, durability, and consistent performance.

Can I use a 6.5 Grendel bolt with a .338 ARC upper?

Yes. .338 ARC was designed to use a 6.5 Grendel Type II bolt, allowing builders to utilize compatible bolt carrier groups while only changing the appropriate barrel and caliber-specific components. Always verify compatibility with your specific upper receiver and manufacturer specifications before assembly.