That's a great question, and a tough one. I don't have a real answer for it, but I can tell you what I do know.
I've built rifles with Proof carbon fiber wrapped ("CFW") barrels for a few 3-gun shooters. No one has reported a prematurely worn out barrel.
One very successful shooter reported his 18" Proof CFW barrel was still shooting considerably sub-MOA until 5000 rounds, when it turned into an MOA gun. He asked me to look at it, which I did with a borescope. The bore was extremely fouled. I asked him what he used to clean it. He replied he used Break Free.
Gun cleaning nerd that I am, I threw up in my mouth a little. But, if he went 5000 rounds shooting sub-MOA using Break Free, it is obviously better than I thought at cleaning barrels.
We did the full KG treatment on the bore, to include numerous passes with KG-2 bore polish on VFG felt pellets. The barrel cleaned up beautifully. Surprisingly, after that many rounds, there was no throat erosion. In fact, the barrel exhibited far less heat checking in the first few inches of the barrel than I would have expected to see at that round count.
The shooter in question had made it clear he loaded his own ammunition for competition shooting. I asked if he shot light loads and he replied that just the opposite was the case.
The barrel reportedly returned to its sub-MOA performance.
So, I give you this one example. The round count of course cannot be verified. But, even if the shooter mentioned above only had 2000 rounds down the barrel, it still looked damn good.
Admittedly, I don't put a lot of rounds through my guns these days. But, if I build another precision AR' for myself, rest assured it will have a Proof CFW barrel in it.
