I have a Rem 40xbr that was set back and rechambered to 22x47 Lapua. I use a Bib 52 grain FB bullet. Barrel is 25 inches and speeds with RL 15 at 35.5 gr. are 3650. While the rifle was not intended for varmints, I have taken one Coyote at the end of my pasture about 200 yards. Devastating effect. Definitely not good if wanting to save pelt. Case not difficult to make - I use 6.5x47 Lapua brass to start with.