Here's some chrono data that I shot yesterday
Sierra Match Kings -168gr
Lapua Brass
CCI BR Primer
IMR 8208 XBR
48 DegF
Rifle- Remington 700P (26") in an AICS stock with a round count at 360 before this session
-I shot 10 rounds of the each load
-there were 10 pre-count rounds sent downrange before the session to heat up the barrel.
-Chrony Beta Master at 10 ft from barrel
42 grains = 2688 fps+/-12
42.3 grains = 2713 fps+/-13
42.5 grains = 2731 fps+/-13
42.7 grains = 2727 fps+/-16
42.9 grains = 2745 fps+/-14
43.1 grains = 2752 fps+/-12
Muzzle velocities with XBR are a little higher than with Varget (by 50 fps) and a lot higher than with RE15 (by 150 fps) for similar powder weights. There were no visible pressure signs on the casings but I haven't measured them yet.
This was an exercise to prove to a friend that at 100 yds ladder tests on this round are inconclusive. The next round of tesitng will be on 1" round pasters at 100 yds. One paster per load-type.
I'd love to hear comments or criticism of my findings and methods-as long as they're constructive!