I learned a lot Tuesday! Shot several different load combinations at both 100 and 200 yds. Also performed a gradual tightening of the aft hold down screw on my model 12 BVSS .223 with groups fired at 3 different degrees of torque. Results indicate that it needs to be fairly tight (I don't have an inch pound torque wrench, so I went by feel) and I probably need to bed this action as the rear action screw never does feel like it hits a solid bottom.

I shot various combinations of 53 gn Hornaday V-Max, 52 gn Nosler Competition HPBT, with IMR 3031 and IMR 8208 XBR powders with two different COAL. I tried to keep the barrel fairly cool, and tried my best to ignore the two AR15's on my right that were burning through 400 rounds an hour with brass hitting the pavement behind them that was burning hot to the touch. Not kidding, I mean blister-you-in-a-heartbeat kinda hot! Didn't have my IR gun to check temps, but I'd be willing to bet they were well over 300 degrees.
Managed only a few fliers while flinching, but it took concentration :)

Clear winner was Nosler set .040 off the lands over 8208 loaded to 3200 fps producing 5 shot, holes touching holes groups at 100 yds. The V-Max was only slightly worse, but still mostly hole touching hole groups when loaded over 8208. Only problem I had was re-adjusting my scope back to 100 yards after the 200 yard groups. Did not immediately return to zero. Took a few shots to work it's way back in. Guess I'll have to shell out for a better scope and cry all over again. Can't say I wasn't warned