I purchased a used borden 6br and because of its 269 chamber I am buying new brass. My old rifle had a 262 neck. The rifle has 2 6br barrels one with about 1000 rounds the other new. I have been waiting because I keep thinking I may want to chamber to a dasher or brdx.Should I chamber now or wait? How does forming used brass work should i shoot it for a while?









