Google 6MMBR site, particularly ‘Jerry Tierney cleaning F Class’. Jerry was an IBM engineer and kept
meticulous records of scores in F matches, related to cleaning frequency. With accuracy and precision
as our goal, it’s best to let the barrel tell you when it wants to be cleaned .
Different powders/ loads in different calibers require different regimes. My 6.5x 47 with H4350 will go
a couple of hundred rounds before cleaning. 300 N M with H1000 or slower powder , prefers to be
cleaned at no more than 50 rounds. If you are shooting 308, you may be surprised at how infrequently
you can clean , and maintain accuracy, using Varget powder.