That’s very interesting, I’d not heard of the moly coating working in that way. I’ve heard of TiO2 and some plastic materials being used to form a thermal barrier between the propellant gas products and the barrel in larger (artillery/tank) weapons, but not moly. Has any research been down to verify the effect or other materials used?

Yes, I quite agree, the lowered friction, would lower the time period the projectile is in the throat area as the shot-start pressure is lowered, it starts moving earlier. You still have the problem where you need a bit more propellant to attain the same velocity due to the slight mis-mash of the powder burn rate, the gas producton rate is not optimised to the bullet type. Perhaps a slightly faster buring propellant should be used, as per lighter bullets.

EDITOR: Here is the direct link, http://accurateshooter.net/Blog/barrellifeupdate.xls . Note this is a very small file and should download almost instantly. It is a MS Excel file. You will need a program capable of opening Excel files. If you can’t find the spreadsheet after right-clicking on the link, check your default download folder for your browser.

psi, not Psi
kJ/kg, not KJ/Kg
Either ‘heat of explosion’ or ‘calorific value’, not ‘heat capacity’.

Also, as I can’t see the formula used, how are you figuring in the effect of bullet frictional reducers (moly, etc)? Are you using the fact that their use will lower shot-start pressure and hence peak pressure for a given charge mass? Seeing as most barrels will be retired from use due to throat erosion and not bore wear, the effect of moly coating on barrel wear has always confused me? To get the required velocity means, for the same propellant type, upping the charge mass, which negates the advantage of the reduced shot-start pressure? Though I suppose such coating could be used to reduce bore (copper) fouling?