I've got conical loads worked up that are really accurate at 125 yards.
With conical, also use a Wad and seat that first on the powder for a gas check.
I love shooting conical.

Also you can use the No13 on a patch, but just plain water or spit will serve the same purpose. When shooting sabot, I always shoot from a bone dry and clean barrel. I spit/alcohol/dry swab/patch inbetween each shot. You may need to swab more or less depending on fouling.

Flinching or pulling/anticipating can also cause a stringing effect. Make sure when the ignition goes it is a "surprise".