Al, I will take a shot at this one although I am not sure that there is an exact answer. I just looked back at the results of this month’s midrange match and noticed that several shooters matched or bettered there high relay score during the third relay. These rifles were still shooting pretty well after 70 or so shots. Would a clean barrel have shot better, do not know but did not notice anyone cleaning. I will also say that I have attended benchrest matches where many shooters cleaned after ten shots. Did they benefit? I would bet they thought so, but who knows. I am from the school that believes that one cannot hurt a rifle by properly cleaning it therefore I clean my rifles before the next match. I use bore guides and try to ease the cleaning rod back into the muzzle of the barrel. Final answer somewhere between 1 & 100. WWE
I like to clean mine after 40 or so rounds but in F class you don’t have the time to clean. Would it help? I don’t know but I have thought about shooting a different rifle for last relay just to see. I don’t think there are any rules against doing this. If there is someone let me know.