I was on vacation last week in the Mammoth Lakes, CA area. I had a great trip with a great group of guys from church. We’ve done a trip every summer for the last four years. That delayed me somewhat from posting the results of my range trip with the first handloads for my 300 WSM and the first use of my Athlon chrono. Jim was right, I love it.
Now for the good stuff, how it shot. I used once fired Norma brass from a factory load, with a 180 gr TTSX over Ramshot Hunter powder in a Tikka T3 Roughtech. I was going by the Barnes load data on their website and started at 69.5 gr, then stepped up to 70.0 gr, and finally to 70.5 gr. The max load is listed at 72.5 gr for a published velocity of 3107 fps. I only had 18 cases as I messed up two, so I loaded 5, 5, and 8 at each charge weight respectively. It’s not like I was pushing max, but I had no heavy bolt lifts or pressure signs on the brass.
The first load at 69.5 gr gave me an average velocity of 2974.4 fps over five shots, with a SD of 9.2. Stepping up to 70.0 gr I saw an average of 3036.2 fps over 5 shots, with a SD of 20.0 (ugh). Finally at 70.5 gr I recorded an average of 3042.2 fps over 8 shots, with a SD of 12.7. The last load giving a 3 shot group of 0.78", a three shot group of 0.81" and a two shot group at 0.91". I think the rifle can do even better and we are seeing my limitation here, though I will note I had 15 mph winds that day with gusts higher. That said, I need to train more with the rifle!
I think I am going to continue with 70.5 gr of Hunter and get some premium brass. Last note, it was the first time out with the Backfire Recoil pad on the gun. What a difference. With a radial break and the recoil pad the percieved recoil felt less than my 308 Win, which I also shot. I’m a believer in the Backfire Recoil Pad.