I think a barrel always lasts longer the more moderately you load for it. I have some rifles that I load fairly hot and others conservative. Once I get a hot load worked up for a rifle, I'm sparingly with my shots. I've got a 7mm stw that I usually just make one cold bore verifying shot in one day. It's proven itself so I can practice more with a more moderate less costly round to shoot. I do a lot of practice with a 6.5 creedmoor. But with the OP running a prefit, he can rebarrel fairly economically. I'm pretty much the same way with my prefits, Im not too much worried about burning it out cause I can rebarrel them fairly cheap and easy.Don't know if this has been mentioned, but if shooting at speeds way over the book won't that burn a barrel twice as fast.
Can't many rounds available out of the barrel.