Lesson learned

[Earle]

A few months back i purchased a used Rem 750 chambered in 35 Whelen. Got 11 full boxes of various ammo with it. Did a quick cleaning on it and finally got it to the range last week. Functioned fine, but grouped like a shotgun with all the ammo i tried. Brought the gun home and the barrel, on closer examination seemed pretty dirty for the number of rounds i shot.
Did a complete teardown, including barrel removal, and starting cleaning. Got the barrel to the point where it looked clean and reassembled. Gun seemed to cycle much smother and everything seemed tighter.
Back to the range yesterday and shot groups of 1.5" (200gr) and 1"+(250gr). I was happy. Got home and decided to clean the barrel again, but without removal. Using an undersized jag, I pushed patch's thru from the muzzle end. This is where it gets interesting. As of this AM, i have gone thru over 200 patch's and still getting heavy copper stains. Makes me wonder if the previous owner ever cleaned the barrel. Strange because cosmetically the rifle looks like it just left the factory.
One further note. When i initially cleaned the barrel i did co from the chamber end, using a brush, patch's and Boretech. Patch's appeared clean. Cleaning from the muzzle end, using only patch's seems to be removing massive amounts of copper, far more than the dozen shots i took would cause.

 

[Joker12]

Have you tried Sweets 7.62 solvent. Its a very aggressive copper remover. Stinks but works.

 

[JimP]

I use Barnes CR-10 for cleaning following the instructions. Saturate a patch with it and swab the bore, then let it sit for a while followed with a brush then dry patches. Once clean I'll follow with a light coating of oil.

A heavy fouled barrel is going to take a while to get clean. It doesn't matter if it is copper or lead. But then once it is clean it doesn't take long to clean it up after a shooting session.

 

[Earle]

Never tried the Sweets. Used Hoppes for years, then switched to Boretech. Seems to be removing significant copper deposits. What i find amazing is the difference when cleaning from the muzzle end. Clean from the chamber end and very little copper. Switch to the muzzle end and the patch's come out pure green. Weird.