Re: 338 r.u.m. 300gr otm 2970fps!!!
Well, I will cast an opinion for what it's worth. I think you have created a perfect storm. High velocity, 4 grove with deep scribing and a fast twist rate. The bullets are damaged in the tube from all this. I would recommend you go to the 300 OTM's. Their jacket is a little thicker and I think they will serve you much better.