Re: Load Development
This really depends on what you're doing with the load. For my long range and mid range loads, I need 20 round groups, because that's usually what we shoot in competition. If you're hunting, three rounds should do it, but I'd want to repeat it several times just to have some statistical validity. It's the large round count groups that really tell a story, and that can be obscured with small groups.
As an example, with rimfire match ammo, it's often graded by group size. Testing will consist of five ten-shot groups, and a fifty-round composite of those same groups (electronic targets make this easy). While the five ten-round groups may individually measure completely on par with a much higher grade of ammo, the fifty-round group will always be the real deciding factor. Neat stuff to watch, and really puts it all in perspective. Also gives you an insight into the inherent shortcomings of small round-count group sizes.