If you have shot any type of comp with rim fires, you will know very well the effects of powder fouling on those bores.
Every rim fire I have had has had a dull surface, in relation to the rest of the bore, at 6 o'clock where the powder fouling settles after each shot. This occurs in relatively fewer shots than you would expect.
Now this, like any carbon, is what's doing the damage, not the bullet, lube or gases.
Look at it this way, a clean rope rubbing on steel, compared to a dirty rope rubbing on steel, the dirty rope is going to do more damage faster.
Just a heads up, I do not, and will not use bore snakes on ANY of my expensive barrels.
I also do not, and will not use bronze brushes of ANY description on my expensive barrels.
I also lead slug lap my barrels, if they shoot well to begin with, to improve the cleaning of said barrel. A barrel that fouls and then shoots rubbish in 20 shots doesn't stay attached to my actions for long.
Luckily, I haven't come across more than 2 barrels that didn't wake up after lapping, those 2 were sent back.
A button rifled barrel really shines after being lapped, as do cut rifled barrels.
Bore snakes are just a gimmick to sell you an extra piece of useless equipment. It may take a little powder residue out of the barrel, but it's not going to touch ANY copper fouling, even if you use a solvent.
To the poster that mentioned carbie cleaner, YES, use it, it will soften and remove most of the carbon even before you run a patch down the bore.
As I have mentioned on these pages before, I worry about carbon, not copper between matches/sessions in my barrels.
I clean with Carbie Kleen & Hoppe's No.9 while at a match, this may be after 40 or 80 rounds a day, but the rifle doesn't get a full clean for 3 matches so I can then see throat erosion movement.
You guys need to follow people like Eric Cortina and F-class John on YouTube, they know what works.
Cheers.