Eldermike, like I said, I don't do any formal target shooting, but I have seen over the years that my best groups come between rounds 3 and 15 on the 220 Swift, and it's a custom barrel. It likes a fouled barrel, but not a really fouled barrel. I have a new 260 with a Brux barrel, and it doesn't seem to foul much at all, so clean or dirty it shoots about the same (which is extremely well).
And on another forum I'm on, it seems like some of the guys feel like shooting 400 rounds between cleanings is Ok. Seems odd to me, but you can't change their minds.
My thoughts on cleaning frequency are more along the lines of light carbon fouling is Ok and a certain amount of copper/gilding metal laydown is best for accuracy. A while back I got one of those new gets-all-the-darn-copper-out cleaners and I actually saw a minor degradation in accuracy in one or two rifles. I had to copper it up a little to get back to where I was. So I don't take out all the copper any more. The Brux barrel is so new and fouls so little that I don't know yet what it likes best.