can't give imput on a bolt gun but from an "evil black rifle" 1:8 works fine for both heavies and light I run 110gr v-max's and 208 a-max's (some run as heavy as 240smk's or 254gr NOE cast bullets) I use lil gun for 110's and aa1680 for the 208's and 150's(only reason I run a powder so slow is for gas volume to cycle the AR gas system.
Bookmarks