How to Coat Bullets Using a Vibratory Tumbler
While “naked” bullets are just fine for most applications, some shooters like to put a friction-reducing coating on their projectiles. Coating bullets can benefit guys who run very high round counts between barrel cleanings. Reader Mike Etzel has come up with a simple, cost-effective way to apply HBN, Moly, or Danzac (WS2) coatings to your bullets. And you won’t need any expensive gear other than your regular vibratory tumbler and some small plastic containers.
Mike explains: “For a number of years I have been using a very convenient way of coating my projectiles with DANZAC in a tumbler. Instead of using a separate tumbler filled with DANZAC and stainless steel balls for coating applications, use small resealable plastic cake or pudding cups filled with stainless balls and DANZAC. Each cup will accommodate between 20 to 70 projectiles depending on caliber once the polishing balls and DANZAC are added. When I need to polish some cases, I insert the sealable plastic container(s) into the polishing material in the tumbler, add cases to the media, and in the process clean cases and coat the projectiles simultaneously in one tumbler. This does two operations in one session, saving on time and resources.”
While Mike uses DANZAC (Tungsten DiSulfide or WS2), you can use the same impact-tumbling method to moly-coat your bullets, or to apply HBN (Hexagonal Boron Nitride).
TIPS for COATING your BULLETS, by GS Arizona
1. Start with Clean Bullets. This is simple enough, but some people overlook it and others overdo it. Get the bullets out of the box, wash them with warm water and dish soap and dry them. No need for harsh chemicals, after all, we’re only removing some surface dirt from shipping and maybe some left over lanolin from the forming process. Don’t handle them with bare hands once they’re clean, your skin oils will contaminate them.
2. Get Everything Hot — Real Hot. This is probably the single most important element in producing good-looking moly-coated bullets. I put the tumbler, the drum and the bullets out in the sun for at least 30 minutes before starting and then do all the tumbling in direct sunlight. On a summer day in Arizona, everything gets to the point that its uncomfortably hot to handle. If you are tumbling in the winter, you should heat the bullets in some form, a hair dryer can be useful, but they will cool off in the drum if you’re tumbling in cold temperatures. Your best bet is to plan ahead and do your coating in the summer. I coated about 3000 bullets in a couple of days recently to see me through our winter season (we’re a bit reversed from the rest of the country in terms of shooting season).