McMillan A4 Stock for the USMC M40A3 Sniper Rifle - for Badger trigger guard

McMillan A4 Stock for the USMC M40A3 Sniper Rifle — Badger Ordnance Trigger Guard Inlet | OD Green

The McMillan A4 is the stock that defined the USMC M40 sniper rifle program from the M40A3 onward. When Quantico's Precision Weapons Section selected McMillan for the M40A3 program, they chose the A4 pattern for its combination of adjustable length of pull, integrated cheek riser, and a fiberglass-over-foam construction that is impervious to the environmental conditions that warp wood and delaminate synthetic alternatives. This specific stock is inlet for the Badger Ordnance trigger guard — the correct trigger guard for M40A3 builds using the Badger M5 bottom metal.

Why McMillan

McMillan stocks are hand-laid fiberglass with a marine-grade epoxy resin system, built in Phoenix, Arizona. Each stock is pillar-bedded from the factory and features an aluminum bedding block that provides a consistent, repeatable action-to-stock interface. The A4 pattern includes a wide, flat forend that tracks naturally off a rear bag, a vertical pistol grip, and a buttstock with adjustable length of pull via spacers. The OD Green gelcoat is the correct color for USMC M40A3 configuration.

Compatibility and Configuration

This stock is inlet for a Remington 700 short action with the Badger Ordnance M5 trigger guard. If you are running a different bottom metal (e.g., Remington factory trigger guard or AICS magazine system), this stock will not fit without modification. Confirm your bottom metal before ordering. The barrel channel is designed for the heavy Schneider or Krieger contour barrels used on the M40A3 — lighter barrel profiles may require additional bedding.

Pair With

→ McMillan A4 Stock for the M40A5 — Next Generation USMC Config

The M40 platform is one of the longest-serving sniper systems in U.S. military history. For M40A3 and M40A5 build questions, CCC has been sourcing McMillan stocks and Remington 700 components since 2017.