Read through previous questions and comments on this issue and have to ask as I am seeing what has been said before. I have roughly 400 rounds through my barrel (67gr RL22, 180VLD, Win Brass) at 3045 fps and it has been great. However, now the groups have started to open up from 0.4 MOA to 0.75 MOA which would indicate throat erosion and the need to chase the lands again for optimum seating depth. Would it be worth switching over to the more depth tolerant and cheaper 162gr AMAX? Realistically it would appear I am only getting a couple of matches, some practice time, and load development out of each iteration of this exercise which to me is too short of an optimum. Any comments appreciated!!!