If I had an angry Griz in front of me and had the choice between the 243 with its speedy 100 grain bullet and the 45-70 with it slow 1400 fps 500 grain bullet, Give me the slow one. Same given the choice between the 243 and the 30-30 with its 170 grain bullet. Velocity does not equal momentum even though it is part of momentum. Velocity does not equal energy even though its part of it. If velocity is all you have, you are in trouble.