Thread: Barrel chop

Greetings again @yogi,
From my records 44 grains of AR2208 with the 150 grain Hornady in a Winchester case chronographed 2,560 fps in a 20" barrel. This would work out to 2,610 fps with your 45 grain load. Your load is 2 grains under max which is more limited by case capacity than pressure and you may struggle to get the full charge in your case but if you can 47 grains of AR2208 should give you about 2,710 fps or perhaps a little more. It seems that once the pressure drops below a certain point velocity drops at a faster rate. Your loads are only giving around 45,000 CUP or a little more where a full pressure load would develop between 50,000 and 52,000 CUP. Your Sierra Game King projectiles should be a good match for the Nosler BT used in the Hodgdon/ ADI data. I assume that the 159 grain is a typo. If you wanted to go to a different powder I would recommend AR2206H 45 grains of that should give 2,720 fps in your rifle and it will fit in the case better. 45.5 grains is book max. Work up using your chronograph though and expect around 80 fps loss below 24" data as you approach max loads. Or just go hunting with what you have, your choice.
Regards Grandpamac.
PS. My Chronograph is an Oehler 35P with a 4 foot screen spacing and has proved reliable for me.