I am starting to load .223 for a RRA varmint AR with a 20 inch barrel, and am having a bit of a issue.. I am Loading Barnes VG 50 gr. bullets into once fired brass, with 23.4 gr of Ramshot TAC powder and WSR small rifle primers. This is the first load test and i am wanting to slowly go up from here.. BUT right off the bat I have an issue.. I shot 10 rounds of lake city mil surplus 55gr over my crono to get a baseline and make sure everything was working properly.. 3154 fps average, all withing 22 fps of that.. Then when I shot 10 rounds I loaded the velocity was 2850 average but fluctuated almost 100 fps either way. I did weigh each load individualy and OAL was identical also. I am using a Lee factory crimp die in this setup, but the crimp is minimal at best. Can the small crimp be causing the difference??