How often should I clean my 22 mag or 17 HMR barrels?
It seems that the ammo is jacketed and may lay down copper deposits.
Will a fouled bore shoot better as in 22 LR?
Any advice will be appreciated
I have no advice for cleaning your 17. I don't own a 17 and I have only fired a couple hundred rounds from a 17 HMR. I have begun using larger brushes on my 22 cal rifles. Brass brushes designed for a 243 do a great job on my 22 barrels. Every time I used a 243 brush for the first time on a 22 it looked like dust was flying out of the barrel. I don't know if this dust was lead and copper fouling but I know there was a bunch of it. I have used more than one 243 brush on my 22. I did not see the same thing when I used a new brush, so it wasn't pieces of the brush flying out of the barrel.
Do not use a nylon brush to clean your gun in the described manner. Nylon will cut into your barrel, causing premature wear. I have seen fishing line cut through ceramic rod eyes. While not tougher ceramic rod eyes are harder than the barrel of your gun.
I never use a brush on my target .22. Just foam let it sit for an hour or so then dry patches out only then solvent and dry patches out. If 17hmr id would use copper solvent instead. And i usually clean the barrel every 500rds or so.. which is about every other time. In between i just wipe down and lightly oil.
I do use nylon brushes in both my buckmark and 1911 with no issues. Even nylon brushes for the little parts and none of them are harder than brass brushes. Also have heard that brass brushes leave small brass hairs in lands and grooves in small bore rifles.
I clean my .17 hummer when accuracy falls off, then I use a bore snake with a little hoppes on it, then another dry one and its ready to go, it is a splinter, small game rifle not a target rifle so this works just fine for me.
I clean every firearm regardless of calibre after each use. With rimfires I usually swab the bore with Hoppes No 9 and let it sit for an hour or so then patch it out. I know some people shoot their guns multiple times between cleanings. I've found over the decades though that cleaning after each range session. Let it go for a long time between cleanings and it's just harder, and more labor intensive. This goes a long way of keeping your forearms in pristine condition. A clean firearm will be a reliable firearm.