Years ago I gave the 65 JLK's a try. There was minimal expansion even when pushed hard from a .22 CHeetah. Went back to the 75 A-max after having several runners from the JLK's. Problem solved.
Paul
www.boltfluting.com
Uh boy

Thanks for that info! Had a buddy try the 52 JLKs going FAST, but he wasn't exactly thrilled with them on coyotes, either...
Just gotta scratch the itch with the 60s, cuz it looks that good on 'paper'. Who knows, maybe they'll hit pay dirt! If not, got backup plans in place for that barrel. Heck, a 55gr Btip @ 4250+ wouldn't be such a bad thing?