My wife and I each own a Remington 40X in .22 RF caliber. Both bought basically as a "pig in a poke"...in other words I never got a chance to shoot either one. Hers is a 1965 Rem 700 based heavy barrel and, luckily, shoots very well...nice groups and she is kicking my (and other guys' butts with it in our 100 yard Mini Palma Matches.!). Mine is a 1964 Rem 722 based rifle and is not too much different visibly from hers other than one having a straight bolt handle and the other a "swept" bolt handle. Barrel measurements are ALL the same and both have had Calvin Elite triggers put in them (we both like 2 stage triggers) and are both in their original stocks (as far as I can tell). Mine shoot shotgun groups (as luck would have it) and I figure that somewhere in its long life someone has ruined the barrel with a cleaning rod, so I decided to do an experiment on it. What I decided is to either ruin it completely by cleaning VERY HEAVILY ( I am kind in the market for a good replacement anyway) OR maybe just find out how clean I can actually get it. BTW, after spending literally ALL DAY (stuck in the house here due to COVID 19 and bored to death!) on cleaning with patches, bronze brushes and nylon brushes using several brands of bore goop (another experiment, I guess). I am still getting white patches that come out REALLY BLACK from the groove areas---which I figure must mean the thing has NEVER been really cleaned and likely has 56 years worth of lead in it. BUT, it does have me wondering if there is ever going to be any end to the black (lead?) gunk and the patches will come out looking fairly pristine! Have any of you ever messed with something like this that started out with really black patches? And if so, how long did it take before the patches looked like the rifle was clean? Since I am planning to rebarrel this thing anyway, I am likely going to clean it to the point of just totally ruining it....either that or the patches will start coming out looking OK and the accuracy will (dreaming here maybe??) come back. Who knows? Anyone ever done anything like this? I'd like to hear from you!!