After hastily shopping on Midway and accidentally purchasing a bullet comparator set instead of a headspace comparator, it got me to research this tool. On its face, it seems like a useful tool, and the reasons for using it pass the smell test: bullets aren't 100% uniform, so measure bullet depth from the Ogive. So, my question to y'all is, does anyone on here use a bullet comparator when loading for a 308 gas rifle? Most videos and articles I've seen were for bolt guns, which makes sense as they have more freedom in OAL length, whereas gas guns are limited by the magazine. When you guys reload, do you base your bullet depth on OAL or Ogive measurement? and if you use a comparator, how do you determine your depth as getting "close to the lands" isn't really what you chase with a gas gun given its constraints?
Also, (and I'm sure I can figure this out by putting a few rounds through the press) does the bullet seating die set the bullet depth bases relative to the ogive? Basically, if i get an ogive measurement I like, and the bullets aren't all the same length, will I have to adjust the bullet seating die for every round to get consistent results? or vice versa if I choose the stand OAL of 2.8" does the seating die consistently pumped out OAL no matter discrepancies in the bullets themselves?