sights? glasses? aiming point size and shape - all can make more difference than the load.
I have no experience with dry patch shooting, sry. My own .45 and .40 bls. a GM and Goodioen, both would
put 5 into a 1/2" c to c, using balls: .005" under in the .45 and bore size and .002" larger, in the .40. Some groups would run
up to 1"- that's what happens with fliers. off shots, poor holds, etc.
Both used wet patches and 10oz denim- that's .0225" thick, using LHV and 75gr. 3F, or 85gr. 2F in the .45, and 65gr 3F and 75gr. 2F in the .40. al GOEX
The same groups could be shot with water based lubes - WWWF + a bit of neetsfoot oil & 65 and 62gr. 3F GOEX. I used 'British Express-type sights, bead front and wide V rear.
I know, generally not thought to be 'accurate' sights.