Well, I learned quite a bit today. Went to Range 14, got myself a membership ($60 for a year? 3 visits and it's paid for itself). Set up my new Competition Electronics ProChrono DLX as directed. And off I went.
I'll tell you what, I really learned a lot about how much the RAR's short barrel length (16") affects velocity. My Lee scale's calibration was still good (0 read 0, 25 read 25). Velocities were just 200-300 lower than what Sierra claims based off their test rifles. Fired some Wolf Gold 55gr just for comparison and that was 300fps slower than what Wolf claims. It's one thing to hear about barrel length affecting velocities but actually testing it and seeing the results yourself is really cool. Interesting link I was just reading: https://www.chuckhawks.com/rifle_barrel.htm
No max or overpressured loads were used in today's testing. Just modest loads slightly above minimum. Velocities ranged from 2450-2700 depending on power and load. And that sounds slow as hell to me. But the accuracy was there. Not so much with the Win 748 powder. But I had a few 5 round groups around 0.7-0.72" and managed a 0.61" grouping with H335 for a 69gr SMK.
So am I thrilled with these velocities that don't touch Sierra's listed velocities? No, but the fact is my barrel is about 8" shorter than what they test with. But am I happy with getting standard deviations as low as 13-20 fps and tight groups at 100 yards with a headwind of about 10mph? Hell yes. It's a short, budget hunting rifle. It's not meant for competition. But dear God is my setup with it fun as hell.