Along the evolution of the Marine Corps' M40 sniper rifle, the M40A5 added night vision capability for the PVS-22 to the M40A3 chassis by adding the front "embedded front rail," or EFR, making it the A5 stock. The early EFRs were made by PGW Defence in Canada, and later Badger Ordnance in the USA. The PGW and Badger formats were slightly different. This Embedded Front Rail system shares the same footprint as the PGW, which is perfect when building an M40A5 rifle. When McMillan is building the A4 Model for the USMC stock, a different inlet is made for either a PGW footprint, or a Badger footprint. Fast Forward to current times, and PGW is no longer making the version of EFR that was built into the M40. SOL Strategic now makes the Embedded Front Rail with the same footprint for building a very similar look to the PGW, so good news for those building an M40A5 military clone rifle.
Note: the M40A5 stocks sold by Charlie's Custom Clones are made to accept the SOL Strategic EFR.
photo credits: SOL Strategic, McMillan, GA Precision, DN308 on M40rifle.com, unknown.