In my early years learning curve , I was shooting scratch built rifle w/ a round bottom groove Getz barrel in .50 cal. .In the early 1970's I was on my own as far as experience with almost no help when I got stuck w/a problem. I had some patch cutting issues , but was told to shoot the barrel and it would fix itself. Magically , at about 100 balls through the barrel , the barrel "broke in". Groups tightened up , and no cut patches. Wish I would have known to steel wool the bore to quicken the brakein time. I now steel wool all the barrels I use.