Sorry about your pup. We were lucky to have a Vet who would come to the house the last 2 times it became necessary.
Still two of the worst days of my life.
I'll offer a .308 anecdote from my former neighbor here in FL. He grew up on a ranch in Rhodesia and later became a PH.
The boarding school in S.A. would send them home for a month 3 times per year instead of our customary 3 months off
once a year. Upon arrival at the ranch he would take his Mauser .308 out and shoot an Impala. Said Impala was then traded for
a brick (1000 rnds) of 7.62 ball at the nearby government run range/shooting club. He would then while away his time burning up
that ammo on targets of opportunity, typically going through 3 1/2 bricks in his 4 weeks of vacation. Imagine how much confidence and
skill accrues from all that practice! Probably why he was much enamored of the old .308 all these years later.