I have a re-barreled Rem 788 in .22-250 AI. I received the specs for the finish reamer that was used to chamber it today, and I noticed the overall chamber length from bolt face to end of neck is 1.920 inches. That surprised me because the SAAMI spec for .22-250 is 1.912 inches, and fire formed AI brass ends up shorter than that. My Lapua brass seems to vary a lot. I am seeing a range from 1.872 to 1.894. This is with the same number of firings (fire forming plus 2). It doesn't seem like I will ever need to trim brass for this rifle, but I would like it to be more consistent in length. I guess I could trim it all to match the shortest rounds. My fire forming method is loading the virgin brass with a max .22-250 load using Varget with a 55 grain bullet. Has anyone else seen length variation like that in their fire formed brass? And does anyone know why the reamer would create such seemingly excessive chamber length?
