I went back out to the range this morning and shot some more groups. I'm sad to report that, while many SK varieties shoot good to excellent groups, I cannot use anything SK as match ammo. With very few exceptions, in every mag of SK the fifth round will misfeed. It appears that the round gets pushed downward while it's moving forward and the rim isn't popping up and free of the feed lips. The rim is then stuck under the forward part of the feed lips and as it is pushed forward it just continues to become more vertical until it is finally standing straight up at the front of the magazine. This has only happened with SK and it happens consistently with every variety I've tried. It's a bummer because SK shoots pretty well out of this rifle. I did find that if I reached into the receiver and pushed the front of the fifth round back down into the mag a little before bringing the bolt forward that it will feed fine, but I can't do that during a match so SK is off the list.
I also found that the new Eley Semi-auto Benchrest Precision ammo shoots very good out of my rifle and gave an average of 1097 FPS with an ES of 21 and a SD of 5 for the 25 rounds I put over the chrony. As long as I could hold my concentration it would put shots touching at 50 yards. I've found my new match ammo, I think.
I also found that the new Eley Semi-auto Benchrest Precision ammo shoots very good out of my rifle and gave an average of 1097 FPS with an ES of 21 and a SD of 5 for the 25 rounds I put over the chrony. As long as I could hold my concentration it would put shots touching at 50 yards. I've found my new match ammo, I think.