Anyone shooting the 105-115 and using a AI magazine, I am shooting 75gr Amax at 3770, 26", and have a little room left. I want to do another 243AI/w a 1/7 or 1/8 with a long barrel maybe 29-30" and shoot the larger weight. I have taken Groundhogs a little over 800yds already/w the 75's. I...