How much weight do you all put on standard deviation versus group spread when developing a load?
Sometimes I find that I get a good group spread but the standard deviation is mediocre and vice versa. I would say there is a lot of human factor in group spreads where standard deviation is more objective but ultimately aren’t we developing an accurate load?
Brendan, it is possible to get a very good group at 100 yards with a large variation in velocity between each fired cartridge. The impact of the variance in velocities does not show up as much at close range.
Shooting and tracking your group size along with shot to shot velocity consistency will get you consistent groups as you go out further in distance.
If you do not have a chronograph, then shooting a good group at 100, then moving to 300 or farther will show the group opening up to larger sizes, or holding it’s size based on the estimated spread from 100 to 300 or whatever the shooting distance. All things being equal, a 1 inch group at 100 will produce a 3 inch group at 300. Things that impact group size can be a lot more technical but that basic way of looking at your data will get you started.
There is a lot of good information on the net if you search your title for this question. AccurateShooter is a good reference, anything from Bryan Litz is great data as well on the topic.
Good luck
Read this when you have a minute.
Thanks for the reply. This article is helpful. It seems collecting more data is the answer.
Yep, information helps. I would just say that shooting successfully is an aggregate of many things, and it is a puzzle to be figured out in terms of getting all the pieces to fit together, consistently, shot to shot. Learned you can kill a moose with a .223 all day long in another discussion this week.
Stay with it.