I've been running the 55gr NBT out of my 6x45 and 6mm-204 and have had no problems other than not very fur friendly. Shot a couple with 62gr VG, had grapefuit sized exits on chest shots and still had one run 30 ft. Going to experiment with 58gr V-Max and 55gr NBT Lead Free this season see if I can keep them in a coyote.
Been shooting 52gr Speer FB/HP and 40gr NBT's out of my 5.6x50R and 22-204 and both have been great fur bullets.
AWS