AR-10 Parts for Sale — .308 Uppers, BCGs & Lower Parts

AR-10 Parts

The AR-10 platform brings .308 Win and 6.5 Creedmoor power to AR ergonomics, but its parts ecosystem is more fragmented than the AR-15’s — two competing pattern standards mean compatibility must be verified before buying. Impact Guns carries AR-10 uppers, bolt carrier groups, barrels, handguards, buffer systems, and lower parts kits, with this guide covering what fits what.

Read our full AR-10 Parts Buying Guide ↓

DPMS vs. Armalite Pattern: The Critical Difference

There is no true mil-spec for .308 ARs. The DPMS (LR-308) pattern dominates modern production — Aero Precision, Palmetto, and most current manufacturers build DPMS-compatible receivers. The Armalite AR-10 pattern uses a different receiver cut and is incompatible with DPMS uppers and lowers. Within DPMS, there are also high-profile and low-profile receiver heights affecting handguard fit. Rule one of AR-10 building: confirm your receiver’s pattern and profile before ordering any mating part.

What AR-10s Share With AR-15s

More than you might expect: fire control groups (triggers), pistol grips, safety selectors, buffer tube castle nuts, and most stocks interchange directly with AR-15 parts. A Geissele or Timney AR-15 trigger drops into an AR-10 lower. What does NOT interchange: bolt carrier groups, barrels, upper and lower receivers, handguards (different barrel nut), magazines, buffers, and buffer springs — the .308’s longer action requires dedicated components.

Bolt Carrier Groups and Barrels

AR-10 BCGs are pattern-specific and caliber-flexible — a .308 bolt handles the entire .308-based family (.308 Win, 6.5 Creedmoor, .243 Win) since they share the same case head. Barrel swaps between these calibers need only the barrel itself. Quality .308 barrels run 16” for general use, 18–20” for precision work; 6.5 Creedmoor favors 22–24” to realize its velocity advantage. Nitride and chrome-lined barrels trade slight accuracy for durability versus stainless match barrels.

Buffer Systems: Where Builds Go Wrong

The most common AR-10 reliability problems trace to buffer system mismatches. .308 ARs use either a rifle-length buffer tube with rifle buffer, or a carbine tube with a dedicated .308 carbine buffer (heavier than AR-15 buffers) and spring. AR-15 carbine buffers in an AR-10 cause violent cycling and battered components. Adjustable gas blocks are more valuable on AR-10s than AR-15s — many .308 barrels are over-gassed from the factory, and tuning the gas system transforms shootability.

Magazines

DPMS-pattern rifles use SR-25 pattern magazines — the Magpul .308 PMAG (LR/SR Gen M3) is the standard. Armalite-pattern rifles use proprietary or modified M14 magazines. See our rifle magazines page for details.

Frequently Asked Questions

Are AR-10 and AR-15 parts interchangeable?
Partially. Triggers, grips, safeties, and most stocks interchange. Receivers, BCGs, barrels, handguards, magazines, buffers, and springs do not — the .308 action is longer and requires dedicated components. When in doubt, verify the part is listed for .308/AR-10 use.

How do I know if my AR-10 is DPMS or Armalite pattern?
Check the manufacturer’s spec page — most modern rifles (Aero, PSA, S&W, Ruger) are DPMS/SR-25 pattern. Visually, the Armalite pattern uses an angled cut at the rear of the receivers where DPMS uses a rounded profile. If your rifle takes Magpul .308 PMAGs, it’s DPMS/SR-25 pattern.

Can I build a 6.5 Creedmoor on an AR-10 lower?
Yes — 6.5 Creedmoor uses the same bolt face and magazines as .308 Win, so any DPMS-pattern lower works with a 6.5 Creedmoor upper. Many builders run both uppers on one lower: a 16” .308 for general use and a 22” 6.5 Creedmoor for long-range work.