If you start shooting Moly-coated ammo through a new match grade barrel do you always have to?

I have a new AR-10T SuperSASS and it suggests that I should shoot Black Hills Moly-coated ammo for the best accuracy. If I start shooting moly-coated ammo first, will it damage the barrel if I go back to just match grade ammo? What if I keep changing back and forth between moly and regular match?|||The moly bullets do produce different pressure profiles than the non-coated bullets. There is some transfer of the moly coat to the barrel, but not much and you will remove most while cleaning. Since there are different pressure profiles the SAMMI specs are what you need to go by. Even with some moly transfer to the barrel it wouldn't be enough to ensure same performance with the non-molys. Changing back and forth probably won't damage the barrel, but the pressure differences will effect the gas flow and operations. Ballistics and point of impact will also be effected by going back and forth.


There is a similar issue with the Barnes coated bullets as to being a different pressure profile.I have heard even the TSX non-coated can change pressures as compared to standard construction bullets.





I have a friend who reloads for his weapon and he uses a separate tumbler to apply a moly coat to his bullets before he loads them to the cartridge(never tumble loaded cartridges). Contact the manufacturer of your weapon to see if that is an option to save you from buying the Black Hills ammo. That is excellent ammo by the way. Again the barrel shouldn't be harmed, especially if it is the chromed type,but the other working components might have problems. Talk to one of the Company gun experts to see what other options are available too.


If you reload for it, I do believe you will have to full length re-size and not just neck resize.|||No,it won't harm anything. The Moly builds up as a coating in your barrel. It acts as a lubricant,easing the passage of the bullet with less deformation. In some cases it aids accuracy. If your barrel has a coating and you shoot a lot of non coated bullets the coating and any benefit will be gone until you shoot moly again.