I have a bit of a different - perhaps optimistic view of doubles. My primary hunting double is a Blaser S2. I have .375 H&H, 500/416 Krieghoff, and 30-06 barrels for it. It is designed to be scoped and all three barrels are. Each barrel in each caliber shoots MOA at one-hundred meters using TSX bullets loaded by Hendershots, and each shoots a 2-inch 4 shot L/RxL/R at 100 meters. I sight-in using the right barrel of each - typically 1.5 inches high at 100 meters and have easy point blank range beyond 200 with all three calibers. The second shot is easily minute of antelope out to that range. No, it is not using the rifle as a "traditional" double - but then again, it isn't a traditional design, and the scope can be instantly dismounted for a close range follow-up. With open sights at fifty meters it shoots a single ragged hole with all three calibers. I have taken buffalo to duiker with the rifle - from 20 yards to 200+.
Encouraged, Lance Hendershot and I worked up loads for my two 9.3x74R rifles. One is a German WWI era SxS, and the other a modern French VC OU. The German rifle shoots MOA with the each barrel. At 100 meters the two groups are separated vertically by two inches. We discovered that the builder designed it that way so that the right barrel was on at 100 and that the second barrel fired to the flip-up leaf at 200 meters. Equipped with claw mounts, the scope is sighted in at 100 meters (right barrel) and the cross hairs are also dead on for the left barrel at 200. Ingenious Teutons. The VC shoots almost as accurately as the Blaser, is equipped with a dismountable scope, and is sighted the same as the Blaser barrels.
I also have a pre-WWI 12-bore Paradox. It fires a 740 grain bullet load designed and loaded by Ross Seyfried. We both decided it is more accurate than we can hold. He can do a three-inch composite 4-shot group at 100 meters - I can do 3 1/2 - 4. That is with open sights.
My point is, most of these rifles are capable of quite a bit better than saucer-sized groups at 50-meters.
