10-shot groups to test rifle/load accuracy.

I know most swear by the old "tried-and-true" 3-shot group method while some insist on 5-shot groups. While testing out some handloads in my .30-06 and AR I decided to run 10-shot strings of each load without more pause than it took to write down the velocity from the chrony or reload the next 5 rounds into the .30-06. Figured I would get a better idea of how really accurate the test load was as well as see how the rifle behaves as it heats up and see if I'd get significant velocity changes from heat soak. What I figured with both the Ruger American I have and my AR is that neither seems to care about heat as far as accuracy and only the AR showed any increase in the average velocity with identical loads though by only by about 60fps. Heat seemed to do more to increase the standard deviation on velocities. My .30-06 loads were IMR4895 and IMR4064 and my AR loads used Varget and H335. IMR4895 is supposed to be more temperature sensitive but given how much case there is with .30-06 I guess you'd have to let it sit in a hot chamber for several minutes. Did find that the Ruger really likes 168gr OTM's at about 2500fps though I only had one set made. Seems like a good starting point before I start playing with seating depths.



About 0.80" c-c for 10-shots. Shot this right after warming up with the 5 Federal GM. Only setup for 50 yards because I didn't bring my spotting scope and the wind was pretty variable.