Just own seeing if any one shoots 120 grains of loose 777 with a 250 TC shockwave? Just trying to get an idea of how fast it's going?
You are good for 300 yard kills with that load.
I would be more concerned on bullet placement than speed, starting at 100 yards. BTW, I harvested deer with 85gr 777 loose at 125 yards, with similar sized sabot/bullets. Currently using 85gr BH209 with300gr XTPs & 295gr HP Copper Powerbelts