I don't use moly anymore. Instead I use Ultra Bore Coat in those rifles where fouling can be a problem, especially high-volume varmint rifles. It justr makes more sense to me to coat the bore ONCE instead of every bullet you shoo through it.
At one point I investigated a lot of stuff about moly, and it was darn hard to find good research, believe me. One thing I did encounter was some data from a big ballistics lab. They found that moly tended tobuild up just in front of the chamber over about 50 rounds, then when it built up enough the next bullet blew the build-up out. They could see this in both pressure and accuracy.
I don't have pressure-test equipment, but did see this effect on accuracy in more than one rifle. It might be assumed this is why some moly shooters run a bore-brush up there periodically, to knock the moly back.
I have found that both JB Compound and Moly Magic get rid of moly in the bore, but it may take some work. This is from using a bore-scope to actually see what's happening, not just guessing.
Of course a lot of bore fouling also depends on the individual barrel, and the bullets and powder you're running.
