Re: Fast Barrel on my Cooper?
it's not just the barrel length that matters if comparing to published load data
diferences in chamber+brass+temp+altitude+powder lot+twist rate and/or chrony error can all cancel or stack up to easily 150+/- fps
in fact, it doesn't look like you're using a chrony
rather, it appears you're calculating mv off of come-ups vs POI
so, now you've got possible error in published scope adjustment per click vs actual, plus sampling error from group sizes, variable MV SD/ES, and published vs confirmed BC
you're actually not doing bad
just keep shooting without making changes and make sure everything is consistent before you adjust