That group was shot at 100 yards. .357 Magnum, using Starline cases, Hornady 140-grain FTX bullets, and 12.7 grains of AA#9 powder, lit by a CCI small pistol primer.
I had a couple of other groups that were going to be as good, but on four and five I'd wind up stringing them vertically a bit. On that one I stopped at three. Because it looked so good.
That little sucker is fun to shoot, and really likes the lighter bullets; using 150-grain and up, I can't get this level of accuracy from it. They can be picky, can't they?
I checked back on something, and had another surprise. The Hornady FTX load
velocity was ~1520fps(was only able to chrono a couple of shots). Back
when I fired the same load through a rifle with a 16" barrel, average
velocity was 1451fps. With pistol cartridges such as .357 it seems to
be the general rule that you get the max velocity with a 16" barrel;
after that friction starts slowing the bullet. Well, the mini-Sharps
has a 26" barrel, yet gave slightly higher velocity than the
16". I'm surprised, and pleased. And I need to check into this further.
Also had one of those "WTF?" moments today. Guy showed up with all his stuff and a brand-new Wyndham AR-10, got set up, then "Can I ask you something?" He'd noticed the Magpul magazine was marked 7.62x51, and wondered if the Hornady .308 ammo he'd bought would work properly in this rifle...
So we had a discussion on 7.62x51 vs. .308, and the uses thereof, and got him settled in. Somewhat. Also had a brand-new Burris scope on it, had done no boresighting, so took a bit to get him on paper. Not a new shooter from what he said, but not big on the technical and prep(as in 'get it so it'll be on the target somewhere) end.