check out this .95 caliber rifle - its bitchin!
If it didn't have that muzzle brake, it would really be unshootable.
That 240 guns of powder, (probably about the burn rate of 3031), should give warning. A standard top in load for a 30-06 with a typical 175 grn bullet is around 58 guns of 4831.
A typical 50 cal BMG round has around 230 guns of powder with a 750 grn bullet.