Well with that target rifle of mine, I usually give it a swab or two with Hopps copper solvent and let it soak for an hour or two between swabs and dry patch it then light oil patch it followed with another single dry patch and put it away until next session. This is around 80 to 100 rounds per practice sessions and matches. I dont give it a "super" clean until about 300 rounds. I get to the range about 6:30 A.M. and as soon as they open I put a few fouling shots through it and check my 100 yard zero at the same time. Then according to what the ballistic calculator says after entering temp, barro pressure, wind, etc.. I make up my come up sheet for the fireing lines at the 1000 yard range. The fouling shots seem to help. I do clean the rifle every time I shoot it but I don't "scrub the hell out if it" after every time I shoot it. Barrel life is critical to me and the procedure I've adopted seems to work well. I dont have much if any copper build up as the Krieger barrel is hand lapped. It stopped showing copper for the most part at about 20 rounds at break in. Actually I've already ordered another barrel before the one I have now starts to loose it's precision. I figure I've got between 400 to 500 rounds left before this happens. Developing loads has used up quite a bit of this barrels life as far as precision is concerned.
What your going to see with the .300 Win. Mag. is throat errosion before the actual barrel goes. Especially if your loading ramped up loads for higher fps muzzle velocity and using 190 + grain bullets.
Last edited by mrm14; 08-06-2010 at 03:33 AM.