Interesting Ripp, however your findings don't jive with mine. I don't use a factory barrel any more and that might make the difference.

My Pac-Nor 3 groove .17AH barrel gets a single, sometimes 2 powder solvent patches every 300 to 500rounds - no accuracy loss as high as 600 rounds. It doesn't copper foul at all, so no soaking time is necessary. I use a nylon brush to put the solvent into the bore and loosen the powder fouling - that's all there is. I do not use bronze brushes - ever.

I have resisted getting a .204, due to the greater recoil spoiling the visuals. That's what happened with my heavy barrel .17 Rem CZ - I'd lose sight of roughly 20 % of them. With the .17AH, every one of them is visible, even at 20X to 24X and as close as 100yards - sometimes you can see them expand before they break - depends on the shuttering of the eyeballs and scope accuity.

Also, when shooting rock chucks with a friend's Tac .20 off the hood of his truck (Bozeman, Mt.) & using a bipod, no rear bag, I only saw maybe 20 hits out of 56 kills, 64 shots - he was spotting for me. The ranges ran 404 yards to 440 yards reistered on his Leica range finder. The Rem. M700 rifle had a 20X Leupold on it with a Pac-Nor 3 groove bl. The Tac .20 is virtually identical as far as ballistics are concerned, to the .204, so the recoil would also be identical. We were shooting the last of his 33gr. Vmaxs at 4,250fps chronographed - a bit hot, maybe, but his rifle loved the load. It was a strong 3/8" rifle with his load of 10X. It was almost like shooting a laser, well, seemed that way. Larger game might give better visuals, I think.

Remington M700's in .17Rem. have a history of badly fouling in as little as 15 rounds. That propensity for fouling gave all .17's a bad name - one they do not deserve.

I had a CZ .17 Rem at one time and in 200rounds, would pick up a bit of copper, but not much. At 200 rounds, there was no dropping off in accuracy. It was a solid 1/2 MOA rifle. After cutting the barrel off and re-chambering it to .17AH, I was able to run over 300rounds before accuracy started to open up. It was a 3/8" rifle after rechambering to .17 AH. I put a couple thousand rounds through that re-chambered barrel, then re-barreled it a couple years ago, with a Pac-Nor barrel & chambered that with my Pacific reamer. It will cloverleaf them if I'm lucky.

Here's the Montana trip for rockchucks. We also shot some ground squirrels out the window of the truck, with Ruger semi-auto .22 handguns. That was fun too.
I was not well at that time - was on some pretty stiff morphine due to back problems.
The adult rockchuck's head had just enough resistance for the bullet to work well.