Moly Impact Coating:
This is our process. Yours will vary, but this has proven itself for us.
If you projectiles are to be Meplat trimmed and Pointed, do it now.
Moly is something we're using in a projectile dedicated AR10 Custom Build rifle with a Walther 17-4 S/S, Electro Polished bore. If you're going to use Moly you absolutely must remove any and all traces of copper from your bore. Degreasing the projectiles is critical. Dawn or a like soap,100 projectiles or more in a plastic colander. Place the collander in a bowl large enough to contain it and add Dawn soap and very hot water. Use your hands if you can stand it, or use a plastic bristled dish scrubber and run it back and forth through the projectiles with a swirling scrubbing action.
Remove the colander from the bowl and rinse well with very hot water. Place a large, clean thick Terry towel on the counter and gently dump the projectiles onto the first 1/3rd of the towel. Do not touch the projectiles from this point on other than with latex or like gloves unless your hands are scrubbed clean and free of body oils. Human body oil is as bad as motor oil. I use the disposable hospital latex gloves. They come in a box of 100 and they're thin and super cheap. Your clean hands are ok for spreading them out on the towel. After that use gloves. Spread the projectiles out flat in a close group and let them sit for 15 minutes. Lift up the towel by the edges and roll them into the next 1/3rd area. Repeat
Everyone and his brother has a methodology and most involve small pill bottles in the tumbler suspended with corncob media or the far less desireable Thumbler's Tumbler. I don't.
Method A: I use large 16oz plastic straightwalled jars with a slight taper toward the bottom with screw on lids, and not inside the tumbler in in the media. We use one of our shop made 1/2" thick Sintra tops, made to fit the tumbler/vibrator. Two or four holes (depending on the model) are cut to accept the jars.
Please pay no attention to any pricing shown for these vibrator tops. We don't sell to the public anyway and Graf's has been negotiating on carrying these tops.
Method B: All four jars are spaced evenly around the shaft on their sides, blocked with dense foam.
Place .177 Dawn washed steel BBs in the bottom 1/4 of each jar. Add two heaping teaspoons of Lab Grade Moly in each and seal the jars. Vibrate for three full hours pausing at the 1 1/2 hour mark to remove them from the vibrator top and shake up and down vigorously a few times. Replace them snugly and continue vibrating to 3 hours.
Place 50 to 75 .30 caliber (or whatever, untouched by human hands) clean projectiles in each of the four jars, add a very liberal 2 to 3 Tsp. of Moly and vibrate for three hours. Within reason, you cannot use too much Moly. The unused Moly simply stays in the jar and keeps working on the next batch. Moly does not penetrate the copper jacket like hBN, so unused Moly simply sloughs off the projectile when its sufficiently coated. The jars contained in the Dillon impact coat the projectiles easily 4 times harder and faster than in a pill bottle suspended inside the tumbler in media.
We bought the Sierra Moly coated SMKs to compare to our process. Sierra's and Tubb's seem to be identical in coating. It took almost half again as much effort to scratch ours as it did the Sierras. Our process was given to us by our AR10s builder. He impact coats some 2,000 projectiles a week for his Security Contract buyers of his rifles and for EDM. He uses 4 of the Commercial Dillon Tumbler/Vibrators. He had been using two large plastic mayonnaise jars taped to the tops of his Dillons until we got involved. We supplied him with our custom Sintra made tops and that's all he uses now.
The final super important factor in finishing our bullets came from our AR10 builder. Heat. So much heat that you can barely touch the bullets when the process it done. Our vibrator tops are 1/2" thick flat black Sintra (Expanded PVC), and black absorbs heat like crazy. Our heat sources are large Halogen Body Shop lamps. You have to experiment with distance above the jars to get it right. Too close and you'll soften or melt the jars. Too far and you don't get enough heat. We place them at 45 degrees to the top on either side. If you can find a better or different heat source that works, go for it. Whatever works for you.
Use a large slotted spoon to remove the impact coated projectiles from the jars and transfer them immediately to a dry, thick Terry-Cloth towel.. Grip the towel by both ends, fold them closed and roll the projectiles back and forth in the towel about 8 to 12 times. They're going to come out a bright, rich silver/pewter color and the Moly coat will be very difficult to scratch other than with a steel implement like a screwdriver. You shouldn't be able to remove any at all with your fingernail. They're going to be dead smooth looking with no blotchiness at all.
Terry Towel tumbled.
100 finished ICPs