The cleaning procedure for molybdenum disulfide treated barrels differs substantially from cleaning procedures for non-treated barrels, because cleaning 'moly' treated barrels is essentially a chemical rather than a mechanical process. Most of the recommendations include a powder solvent followed by any combination of JB, USP, and/or Kroil. I highly recommend using a bore guide with a solvent port.

NOTE: Use only one type of powder solvent per cleaning session - DO NOT USE MORE THAN ONE UNLESS YOU ARE SURE OF WHAT YOU'RE DOING, as chemical reactions that are harmful to your barrel may take place if different solvents are allowed to mix.

Frequency of required cleaning of your barrel will vary as a function of : barrel smoothness, moly coating thickness/method, bullet velocity, chamber pressures, powder type, ...

There have been questions raised regarding molybdenum disulfide and barrel corrosion. I've heard that (1) moly attracts moisture, and (2) moly is "an innocent bystander" and any problems are because some who use moly assume it is a corrosion preventative as well as lubricant. It's not. Some people have raised concerns that molbdenum disulfide can actually harm barrels by corroding or encouraging corrosion and pitting. Well, in this article, Precision Shooting Magazine dispells concerns about using Molybdenum Disulfide.

I clean my rifles thoroughly after every shooting session, and the last thing I do is run an oiled patch, sometimes followed by a dry patch (depending on how long I think it will be before I use the rifle again), down the bore - whether the bore is moly'ed or not. Moly won't protect your bore from rust - oil will.

Here a few methods that I've either run across or developed myself:

Method 1 (one I use most often)

• One wet patch with Shooters Choice/Kroil (2 parts SC to 1 part Kroil).
• Attach a nylon or brass bore brush to your cleaning rod, wrap it in a patch, and apply the Shooter's Choice/Kroil mixture.
• Push the brush through the bore, remove the patch at the muzzle.
• Repeat.
• Apply SC/Kroil to your brush and push-pull two or three times.
• Replace the brush with a brass jag.
• Wet a patch with the SC/Kroil mixture and push it through your bore.
• Run a dry patch through.
• If you are NOT going to continue shooting, run one oiled patch (gun oil or 'Marvel Mystery Oil') through the bore and back.

Method 2

• Two wet patches with Kroil.
• Run one dry patch through.
• One patch with USP Bore Paste.
• Short stroke the patch from the breach to the muzzle.
• Two wet patches with Kroil.
• Two dry patches.

Do this after approximately 80 to 100 rounds, depending on the class of rifle being fired.

Method 3

• Attach an undersize bronze bore brush (caliber .270 for .308 barrel) and wrap a clean patch around it.
• Wet the patch with Rem-Oil or Shooter's Choice FP-10 lubricant and pull-push two times to remove the powder fouling.
• Replace the patch and wet it with Rem-Clean bore cleaner.
• Pull-push 10 times to remove the copper fouling.
• Replace the patch and cover it with JB Cleaning Compound.
• Pull-push 10 times.
• Make two passes with an oiled patch.
• Make two more passes with a dry patch.

Method 4

• Attach a bore brush to your cleaning rod and apply Hoppe's #9 or Shooter's Choice powder solvent (once you pick a solvent, stay with it for the entire cleaning session !).
• Push-pull the brush two times through the bore to loosen the powder fouling.
• Replace the brush with a brass jag.
• Wet a patch with Hoppe's #9 (Shooter's Choice) and push it through your bore.
• Wet a second patch with Hoppe's #9 (Shooter's Choice) and push it through your bore.
• One patch wet with Kroil.
• Make two passes with a patch covered with 'Marvel Mystery Oil'.
• Make two more passes with a dry patch.

Do this about every 50 rounds.

Method 5

• Run 2 wet patches, then short stroke 1 wet patch coated with Rem clean or JB or IOSSO paste through the bore.
• Follow this with 2 or 3 wet and 2 or 3 dry patches.

Do this every 50 to 100 rounds. Try wet and dry patches at 50 rounds and use the paste every 100 rounds.

Last updated : 01 March 2000