bellydeep,
On average, I've never found a monolithic that killed as quickly as most lead-cored bullets when using rib shots, given the same bullet weight and velocity.
But give a mono some real zip and they can do pretty well!
John,
I have yet to see them beat a lead core bullet, even once, but haven't given up yet.
Lately I've been launching the 80gr TTSX in a .25-06 and the 150 TTSX in a .300 Wby.
I would think that would be fast enough?
I'll keep trying with the monos from time to time. But so far, I haven't seen any real spectacular kills with them.