By Dick Hatfield
Recently I became aware of a product called Spica Gold manufactured by the Parsec Group in Bel Air, Maryland. (Note: This product is now available as "Plate+™" from Sprinco, USA the authorized distributor for shooter materials from Parsec. Any questions or comments should be directed to Sprinco not Parsec.) This product is a colloidal suspension of extremely finely divided (less than 0.5 microns) Molybdenum Disulfide, or "Moly", in a light oil with various proprietary inhibitors. According to Parsec/Sprinco, one could use the product to coat the inside of a gun barrel and increase the corrosion resistance of the barrel and not have to use Moly coated bullets to get the benefits of reduced galling or copper deposition. Being able to coat the barrel offered the chance to compare various combinations of bare and coated barrels and bare and coated bullets. I have a sporterized Model 1903 Springfield with the original military 30-06 barrel (well used) that had never had Moly coated bullets fired in it. Although not an accurate gun, it would work nicely for a set of velocity experiments. I cleaned the barrel thoroughly with a chemical copper remover (Barnes C-10) until there was no sign of copper and followed this with JB (a very, very mild abrasive) and finally a fine polishing compound used on plastics. I then loaded up 100 rounds using military brass, Remington 150-gr. soft points and H414 powder with a load that had worked well in the past. All 100 rounds were as alike as possible. Fifty of the bullets were Moly coated using the NECO tumbling process. The bullets were 0.065" from touching the lands in order to keep the overall length short enough to feed through the magazine. The experiment first consisted of firing 25 rounds of non-coated bullets through the clean barrel. As expected there was considerable evidence of copper in the bore. I again cleaned the barrel of all signs of copper using the above process. I then fired 25 rounds of Moly coated bullets. There was some copper on the lands following the firing, but not nearly as much as with the bare bullets. (Remember that this is a rough, used, military barrel. A modern, lapped barrel would probably show no copper.) Cleaning was easier and followed the above procedure until there was no copper. The barrel also had no apparent sign of Moly, as it appeared shiny like fresh steel. Following the Parsec/Sprinco instructions, I corked the barrel, filled it and soaked it in Spica Gold/Plate+™ for 5 days (48 to 72 hours recommend) then cleaned with a few dry patches. I observed a dull gray coating on the bore. I then fired 25 rounds of bare bullets in the Moly coated barrel. I observed some copper fouling on the lands. I judge that it was about the same as that following the Moly coated bullet firing. I then ran a few patches through the barrel and made no attempt to clean it. The last test was with Moly coated bullets in the Moly coated barrel. Again there was some copper fouling, some of which was left over from the previous test. But I couldn't see particularly more than before. The velocity (in feet per second and the group sizes are in inches) results were as follows:
Moly coated bullets do cause the velocity to drop as reported in the literature. A Moly coated barrel will give increased velocity as reported by the Parsec/Sprinco. A combination of the two cancel and give essentially the same results as no Moly at all. Note that the standard deviation for Moly coated bullets was over 45% greater than with bare bullets. I don't understand why. There was no apparent effect on group size, but this is no benchrest gun either. How long will the coating on the barrel last? I don't know. Parsec/Sprinco suggest running a patch with the Spica Gold/Plate+™ through the barrel after each firing string, i.e. when you would normally clean it, and you should get 500 to 1000 rounds before a re-soak is needed. We will see. Frankly, coating the barrel seems to have some advantages: no fuss with Moly coated bullets, a slight gain in velocity, and a corrosion resistant coating in the barrel. I have done some reading of the scientific literature on Moly and there is repeated evidence that Molybdenum Disulfide plus water (in the air) plus oxygen (also in the air) will yield a bit of sulfuric acid which is not good on either your bullets or your barrel. I would like to see some more experimenting along the lines of the above. If you are interested in such experiments, contact Sprinco USA, Inc. in Austin, Texas at 800-397-9530 who now offers small amounts of Plate+™ for the shooter.