Re: Determining Group Sizes...?
As Tim said, the centers of the two farthest holes is what you're after, I get this buy measuring from the outside of one to the inside of the other... saves you from having to subtract the bullet diameter is all, which sometimes is not exactly the diameter hole that's left in the paper.
I've shot some smokin groups at 1000 yards, most wouldn't even believe 'em, but none of them were 10 shot groups, just 3 or 5's. Ten shot groups at 1000 yards, I believe, more accurately evaluate the shooters ability to read conditions and changes or lack there of, as just too many variables are at work for most load proving and shooting technique assessments. I like aggs of 10 shot groups at 500-700 yards in calm conditions for final checks on these things for the reasons Tim stated above.
3-5" groups have always made me pretty happy at these ranges with my equipment. I think consistant MOA or better is quite an accomplishment if you're shooting ten rounds at 1000 yards. Often 1.5 MOA at 1000 yards is quite a feat to accomplish if conditions aren't damn near perfect, and really, how often are they.
I'm with DC and like the early morning and late evening for 1000 yard or any range testing. Mirage and wind are usually alot less then, but the bugs in your face are at their worst. [img]images/icons/grin.gif[/img] A comprimise in everything. [img]images/icons/smile.gif[/img]