So someone mentioned the 338 RCM, would be an interesting build for an AR 10.
So why not I have the tools, except a 338 RCM reamer, which arrived before the barrel.
Chambered a lighter barrel, adjustable gas block, magnum .535 bolt carrier, and upper reciever.
Put it all together and the 338 RCM weighs in at 7 lbs 11 oz without scope.
Took it out today to see how it would preform. First round was a moderate load with 200 gr bullet.
All the rest were loading book maximum loads, including sight in loads, with various hunting bullets bullets 160 gr copper Barns to 250 gr Speer GS.
To see how the AR 10 handles the 65,000 psi magnum pressures.
It did well, function well and was accurate, especially for hunting bullets. 5 3 shot groups averaged .506" the 5 shot groups were right at 1".
Brass was made from 6.5 PRC, 4 different manufacturers or names on the brass.
I did notice the weight difference.
The Barns already had loose primer pockets, the Lapua was 50 fps faster, Nosler required an extra annealing as it was brittle. But Norma, Lapua, and Barns all used the same forming steps...the brass does make a difference, on targets, big game is a big target, so not so much.
Most loads were getting around 3200 ft lbs of muzzle energy from the 18" barreled AR 10 with only two powders tried.
A 200gr at 2700 fps seems like a good balance, or 225 for 230 for heavier big game. The 250s at 2400 fps would be for close range smack down.
The 338 RCM is a good hunting round in the AR 10 platform, for those interested.
At least its unique.
So why not I have the tools, except a 338 RCM reamer, which arrived before the barrel.
Chambered a lighter barrel, adjustable gas block, magnum .535 bolt carrier, and upper reciever.
Put it all together and the 338 RCM weighs in at 7 lbs 11 oz without scope.
Took it out today to see how it would preform. First round was a moderate load with 200 gr bullet.
All the rest were loading book maximum loads, including sight in loads, with various hunting bullets bullets 160 gr copper Barns to 250 gr Speer GS.
To see how the AR 10 handles the 65,000 psi magnum pressures.
It did well, function well and was accurate, especially for hunting bullets. 5 3 shot groups averaged .506" the 5 shot groups were right at 1".
Brass was made from 6.5 PRC, 4 different manufacturers or names on the brass.
I did notice the weight difference.
The Barns already had loose primer pockets, the Lapua was 50 fps faster, Nosler required an extra annealing as it was brittle. But Norma, Lapua, and Barns all used the same forming steps...the brass does make a difference, on targets, big game is a big target, so not so much.
Most loads were getting around 3200 ft lbs of muzzle energy from the 18" barreled AR 10 with only two powders tried.
A 200gr at 2700 fps seems like a good balance, or 225 for 230 for heavier big game. The 250s at 2400 fps would be for close range smack down.
The 338 RCM is a good hunting round in the AR 10 platform, for those interested.
At least its unique.
