you have to use the same o-ring when changing carriers. the carriers are to adjust the fit of the o-ring to the bolt stem. use the largest carrier that
there are nine carriers in total, 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5 and 4 although you really only need 0-2.5 (more often than not, 0.5-2). the carriers
This is a cross post from mcarterbrown. I decided to put it in the WTB forum here because I am looking primarily to trade for a micromag.