I admit it—I’m an old timer. I started shooting before many S.W.A.T. readers were born, and my mentor started before World War II!
He was taught (and taught me) that Hoppe’s #9 was the best all-purpose cleaner for firearms—and besides, it has that delightful smell, that light scent of banana oil. Cleaners have come and many have gone, but Mr. Hoppe’s formula #9 has remained.
Along the way, I tried some of these newer cleaners, most of which were as good as, but not significantly better than, my standard. Cleaned with #9, my accurate pistols and rifle remained so.
Then one day I noticed that a particularly accurate rifle had gone from shooting little groups to gaggles. I checked with a known accurate load, and the groups were measured in inches, rather than fractions of an inch. Something was terribly wrong!
I began the search with the scope. Rings tight? Check. Mount tight? Check. Scope fogging? No. Then I moved to the rifle. Stock screws tight? Yes. Evidence of warping in the wood stock? No. Trigger pull still good? Yes. Barrel clean? Well, sort of. There were visible traces of jacket fouling at the muzzle end, even though the bore looked smooth. This could be the problem.
I got out a new bore brush and diligently cleaned the bore, but the traces were still there. Then I got out some Hoppe’s Benchrest cleaner—no joy. I could still see copper in the grooves of the barrel.
Time for the heavy artillery. I had a bottle of Sweet’s 7.62 cleaner, the Australian-made bore solvent revered for years as the ultimate bore cleaner. Sweet’s has a strong ammonia smell, so I only use it outdoors. I took the precaution of rereading the instructions and followed them exactly. I was crestfallen to see the copper fouling remained after two cleanings with Sweet’s. I did not want to have to rebarrel this rifle and start from scratch.
At the time, I was working with Western TAC powder, and in the course of developing some loads, I mentioned this problem rifle to their tech staff. In addition to—and as a natural outgrowth of—their reloading powders, these folks developed a line of gun-care products under the name Montana XTreme. Frankly, I had never heard of or seen any of their products, but I was becoming desperate. I ordered a bottle of their Copper Killer 50 BMG and, for those really fouled barrels, Copper Cream.
They included very detailed instructions for four different types of cleaning: General; Heavy Copper Deposits; Problem Barrels with Excessive Fouling, Rust, or Heavy Abuse; and New Barrel Break-in.
I followed the instructions for Heavy Copper Deposits, which required the use of a nylon bore brush. The Copper Killer has a warning on the top: “Caution, strong odor”—and they are not kidding. This smells of ammonia, much more strongly than Sweet’s. My cleaning effort moved outside, to my “cowboy conference room”—the tailgate of my pickup.
I again followed the directions exactly, using the Copper Killer and the Copper Cream, followed by more Copper Killer. Now, the moment of truth! The jacket fouling was gone, utterly and completely. The barrel was down to bare steel, shiny as the day it came out of the factory. Yee haw, I would not have to rebarrel this rifle!
Several months later, I had a problem with the barrel of my 9mm XD, which developed heavy leading. I had bought some deeply discounted lead bullets only to find they were worth less than what I paid for them. Something was wrong with the alloy, and the bullets would lead barrels heavily, to the point where the rounds would keyhole, passing through the targets sideways. Once again, the barrel did not respond to Hoppe’s, and even a Lewis Lead Remover (brass screens on a rubber mandrel dragged through the barrel) failed to get all the lead out. I even tried shooting some jacketed ammo, which sometimes scrapes the lead out of a barrel, with no luck. But the Copper Killer/ Copper Cream removed every trace.
I could not find a nylon brush in 9mm in my area, but the folks at Montana XTreme told me I could use a brass brush if I neutralized it by spraying it with WD-40 right after cleaning the barrel. Heck, bore brushes are cheap anyway, compared to new barrels.
Few barrels see as much abuse as those on machine guns. At 450 rounds per minute, a 250-round belt takes little time, even in short bursts, to run through a barrel. The concentrated heat of rapid fire can really cause a lot of jacket material to be left in the bore. So there could not be a tougher test for Copper Killer/Copper Cream than the various barrels for my belt fed, some of which have had 1,000 rounds through them in one day. I was very pleased to see that even this tough fouling disappeared after a single treatment with Montana X-Treme products. Every barrel was shiny as new.
I would not use Copper Killer and Copper Cream on a regular basis, as your favorite bore cleaner (or Montana X-Treme’s Bore Solvent) will work for routine cleaning. But once a year, or any time accuracy falls off or copper is visible in the bore, these are the tools to use.