This is .375 H&H Mag Barnes VOR-TX 300gr. TSX Flat Base Ammo. Offering double-diameter expansion, maximum weight retention and excellent accuracy, the TSX provides maximum tissue and bone destruction, pass-through penetration and devastating energy transfer. Multiple grooves in the bullet’s shank reduce pressure and improve accuracy. Bullets open instantly on contact - no other bullet expands as quickly. Nose peels back into four sharp-edged copper petals destroying tissue, bone and vital organs for a quick, humane kill. This ammo comes packed 20rds. per box.