Here's what Brownell's says in their guntech section about moly and cleaning barrels that have shot moly.
GunTech
GUN CLEANING CLINIC: Moly-Coated Barrel Maintenance
Know What Your Customers Need To Know
by: Steve Schmidt
If your initial thought was that moly-coated bullets and barrel treatments were simply a fad to go by the wayside, think again. Today, most commercial and specialty bullet manufacturers are offering moly-coated projectiles, and sales are sky-rocketing.
With moly-coated bullets and barrels your customers may experience longer periods of accuracy between cleanings. But like in all other cases, cleaning is a necessity.
Moly is here to stay until technology replaces it with something better for those who shoot a lot. And, your customers are going to want to know about it. In this Cleaning Clinic, we'll take a closer look at preparing a barrel for use with moly and address routine bore maintenance for moly-treated barrels.
Pre-Moly Barrel Preparation: Getting Down To Bare Metal!
Assuming most first-timers will be using moly in a seasoned barrel, let's go from there. Make it clear to your customer that nothing is gained by spreading moly over a contaminated bore surface. Stress the importance of starting out with a clean bore. Nobody enjoys it, but a good-old-fashioned, elbow grease cleaning removes all traces of lead and copper jacket fouling and sets the framework for superior results with moly lubricants.
Tackle this job by selecting a standard, bronze bore brush one caliber oversize, or use our new Double-Tuff™ bronze or Heavy Weight nylon bore brushes in the correct size to match your caliber. The Double-Tuff and Heavy Weight fit tightly and provide a superior scrubbing action. Be prepared to push a little harder than with conventional brushes – the heavy gauge bristles don't flex much and retain their diameter, so you'll see fantastic results and in less time.
Start by using your primary cleaner and scrubbing out the powder fouling. Next, drench your nylon brush with a proven copper solvent such as Sweet's 7.62, Hoppe's Benchrest, Butch's Bore Shine, or go with J-B® Non-Embedding Bore Cleaning Compound worked into a bore mop or a patch wrapped around your bore brush (nylon or bronze). Again, to ensure a good, snug fit, go oversize one caliber if you decide to use a mop. These cleaning methods will remove the toughest fouling, even the built-up crud that hides in the tooling marks and heat stress cracks caused by shooting.
Advise your customers to follow the manufacturer's recommendations closely, especially when using ammonia-based cleaners that can harm the bore when left there too long. If you’re using an ammonia-based cleaner, stick with the nylon brushes. When you’re comfortable that the bore is free of lead, powder and copper, give it the once-over with your favorite copper solvent to ensure those blue-green patches are a thing of the past.
How To Treat Your Barrel With Moly Bore Paste
Wrap a cleaning patch around a brush one bore size smaller than your barrel. Rub a liberal amount of Brownells Moly Bore Treatment Paste into the patch. Warming the barrel with a hot air gun or hair dryer can improve the effectiveness of the treatment.
Swab the bore with Brownells Moly Bore Treatment Paste until you feel a slight "drag" to your cleaning rod (usually about twelve to fifteen passes through the bore.) Run a dry patch ten to twelve passes through the bore to both remove any excess Moly Bore Treatment Paste, and burnish in the Moly Bore Treatment Paste.
Routine Cleaning When Using Moly
Cleaning a moly-treated barrel requires no voodoo magic. Claims, that removing too much moly during a cleaning session will drastically degrade accuracy, are essentially unfounded. How often to clean is largely dependent on barrel quality, caliber, powder choice, number of rounds fired, etc. However, when to clean is less subjective. Teach your customers to learn and judge the shooting characteristics of their rifles. With moly, the time to clean is when the level of bore fouling becomes detrimental to accuracy. It's just that simple.
Lets face it, less efficient, overbore cartridges such as the .17 Remington and 6mm-284 can leave behind enough fouling in 20 rounds to cause a noticeable drop-off in accuracy. Use of moly should extend shot strings at least twofold, but the need for a thorough cleaning is inevitable. Cleaning should be aggressive enough to remove all existing moly residue in the bore and provide a "fresh" bore surface to build on – no moly, no copper.
A winning combination among many moly shooters is Kroil and J-B Non-Embedding Bore Cleaning Compound. Nothing seems to get under and loosen moly quite like Kroil. It penetrates deep to loosen and lift it from the bore surface. J-B gently removes the remaining moly and attacks caked-on copper build-up. For routine cleaning of moly-treated barrels, pass a couple patches of Kroil through the bore followed by several dry patches. Resume with a couple patches soaked with your favorite copper solvent. Let soak for approximately ten minutes and proceed with two or three dry patches. Short stoke J-B about ten times through the bore, followed by two patches of Kroil. Finish by pushing dry patches through the bore until they appear clean and dry.
If the rifle will be put in storage for an extended period, run a patch of gun oil through the bore to prevent rust and corrosion. Before shooting, dry the bore completely and treat a couple of oversize patches or a bore mop with Brownells Moly Bore Treatment Paste. Run it down the bore to burnish the moly into the surface metal. This should reduce the number of fouling shots to regain optimal barrel accuracy (1 or 2 shots) and helps prevent corrosion.
