all i'll ever use for my 6.5x55 for hunting moose is the 140 grain x bullet .
it is the right length to get the bullet remotely close the rifling ( similar in length to a 160 grain round nose ) .
i've never recovered one either , they have always gone straight through the chest . lead bullets almost always get stuck on the inside of the hide on the way out .
oal from tip of bullet , 3.120" ( 140 grain x bullet )
48 grains of imr 4831
remington mag primers
your rifle will be different , so make sure you reduce your starting loads and work your way up .