I recently bought a lightly used bolt action 7mm-08. I cleaned the bore and mounted a SWFA 10x42 scope in good rings and started loading for it. I couldn't get it to put 5 consecutive rounds in less than 1.5moa, which I thought it should do better than. I had been cleaning the bore with kroil on a boresnake after each shooting session. A friend suggested I not clean the bore for a while and see if things tightened up, and about 15 rounds later 5 shot group sizes shrank to .4 moa. This has me wondering how many rounds to shoot before bore cleaning. How often do you all clean your high power rifle bores?