There are other such groups in Robert's book, Gentlemen, some even nicer, most shot at 40 rods, their normal 'rest' shooting range, which was 220yards during the 1880's and 90's.

Horace Warner, gun maker was known to carve his surname initial "W" with bullet holes, at that range, using a .50 cal. rifle of his manufacture, HUGE barrels 2" or more across the flats, shaded sights or scoped and guns weighting 50 pounds & more, shot with 'good' black powder and single cross or 2 strip paper patched bullets loaded through a huge false muzzle. Some shot homogeneous lead, others used bullets of dual hardness, joined in a swage.

It is a tremendous book, Lads, & is comprised of a lot of 'needed' knowledge, if you are interested in that sort of thing.