I loaded the first few rounds of 300 grain A Frames. When seated to the OAL of 3.64 they won’t chamber. I had to go way deeper than I’ve had to with any other caliber/rifle. At 3.545 they chamber with a push from my finger. At an average of 3.538 they chamber fine. I’ve loaded a few rounds with starting loads to try at the range, but that seems like a lot to me. I was really hoping to make these work for my buffalo hunt!