I bought a # to try, seems to give good accuracy in both my 1-7 & 1-8 rifles w/ 55gr & 69gr, burns clean too. I would certainly buy an 8# next time around.
"Given adequate penetration, a larger diameter bullet will have an edge in wounding effectiveness. It will damage a blood vessel the smaller projectile barely misses. The larger permanent cavity may lead to faster blood loss. Although such an edge clearly exists, its significance cannot be quantified".