Has anyone here used Mark's 129 ABLR loading? He's saying 2400 FPS from a 24" barrel. So I'm guessing ~2100 from my 12" GB? Does that sound like a good guestimate? I'm thinking of using this from my 12" for whitetail this fall. Even at 350' ASL I should still be able to get a decent range as long as I do my part with proper holdovers.
ETA: playing with a couple ballistic calculators, my MPBR would be about 240 yds. This would still have plenty of speed at ~1700+/- but energy is now a bit under 900 ft lbs. Enough?
ETA: playing with a couple ballistic calculators, my MPBR would be about 240 yds. This would still have plenty of speed at ~1700+/- but energy is now a bit under 900 ft lbs. Enough?

