Have run into a problem with my m-96 windrunner,.338 lapua barrel.
91.4 R-25, 250 Gn SMK, seated .060 off rifling.
Vertical impact is dead on horizintal will wander up to 3" left and right. Wondering if it is a muzzle brake problem. Brake has a id. of .504, 3 large ports on L & R sides.
Is it...