morning, I reload my 308 with 130gr. Sierra M HP and 135gr. barnes TTSX bullets 210m Fed. primers, Winchester brass. both loads use WW760 powder. very accurate loads. I went to the range last week. changed scopes. resite scope. the 135 barnes chambered well. shot good. the 130gr. sierra shells will not chamber? so checked different shells with 130gr sierra's would not chamber. I neck size only. OOPS. reset the seating depth of the bullets. nothing changed. pulled the bullets, did not have a FL sizer. so I ordered a hornandy match sizer. very good die. while lubbing the cases and resized cases. in process some cases had resistance to the FL process. 3 were removed. now the only thing I can figure out is that the barnes TTSX bullets have groves in the bullets for pressure and resistance. the sierra bullets r match grade bt bullets r sleek and guilded metal. theory the barnes bullets have less pressure when fired in this chamber than the sierra bullets??? the rifle is a custom mauser 98 action, cerkoted, timmey trigger, british machine barrel, BMG. crowned. #6 contour, h&s stock. shoots .750 and better groups.