6000 in a 6 BRX starting with zero freebore shooting H335, 8000 at least with the 6 BR, zero freebore,  shooting H335.
On the dog towns, we shot till we could not see through the scope. In guns with fiberglass stocks, glued in actions, I will fill the barrel channel full of rubbing alcohol as  barrel cooling technique.  All the alcohol would evaporate from barrel heat. 
I am still shooting that same Panda glued into an Old Atkinson stock.  I would be shooting up to 5 rounds per minute, pulling the trigger with my middle finger(Shilen 2 oz).  Rarely ever missed a shot till the mirage started boiling up over and around the mirage shield on the barrel.  I put 10,000 rounds on that 14T hart barrel, and at 8000 rounds, it was still shooting in the high 2's.