The thing is, there are different theories on what exactly the bullet lube does, and I think they apply in different cases. For the purpose of lubricating the bullet, I think moly would work, and that should do well for low pressure uses, and well fit bullets.

The other theory I've heard of lube is that it acts as a gasket, to keep the gas from blowing by, and I think that theory holds merrit as well, and in that case, moly won't do diddly.

I'd even venture that there might be some barrel, bullet alloy and cartridge combos that could get by with no lube.