What constitutes a high round count gun?

[beatledog7]

If it's a 22-250 or a 220 Swift, then 500 rounds may be new barrel time. The action would still be good, of course. Really does depend on the gun.

 

[The Lone Haranguer]

Why? I can maybe understand caliber making a difference some are harder on a gun than others due to pressures but I am not sure why people keep saying it varies from one gun to another.

I think I see where they're coming from. Five thousand rounds would be barely breaking in a Glock, SIG or other modern military/police service pistol, but incredibly high for a little pocket pistol ... or a Hi-Point.