Depends on caliber. High velocity cartridges eat barrels much faster than more moderate cartridges. Them benchrest boys junk barrels when they degrade to an accuracy most of us would be delighted to be getting in the first place.
A very rough guess would be about 3500 for a .25-06, 5-6000 for a .308 or .30-06, and higher than I can count for the pistol calibers.