Well, I tried out my new Prochrono digital and it worked great (until the thunderstorm hit). The chrono was set 10ft from the muzzle. I was testing my normal loads of BL-c2, lighter loads and a new powder wc846. The WC846 is a canister powder and is supposed to use BL-c2 data.
Rifle: AR15 20" target barrel
Lee's data 25.5 gr blc2 3099fps max load 27.5gr 3313fps min oal 2.2
I load mine to 2.26 OAL, all using trimmed brass, PMC SR primer, 55gr Sierra blitzkings, Lee dies and Lee FC die.
Average from string
25.8gr BLC2 2830fps
26.4gr blc2 2870
27.2gr blc2 2930
26.4gr wc842 3088
I understand that a gas operated semi-auto would have a difference but that much? The wc842 is closer to the printed data, has the blc2 formulation changed? Any suggestions would be appreciated.