With fast twist pistols, you can get away with thin patches due to the normal light loads developing low presssures. The lower the pressure, the lighter the patch which provides easier loading. This is why paper ctgs. shoot so well in low velocity, big bores, but not in high velocity, high pressure small bores. Where a thick, .022" patch and .445" ball is needed in a .45 rifle shooting 70gr. to 80 3F, a .45 pistol shooting 20gr. 3F can get by with an easy loading .015" patch and .440" ball. You can almost thumb press the ball flush with the muzzle - the easiest of loading, yet at 50 yards, still shoot into an 1-1/2" off the bags, of course. With such low pressure and speed, there is no fouling buildup and accuracy remains constant. My .45 rifle needs 75gr. 3F, the larger ball and thicker patch to match the pistol's accuracy at 50 yards - it's past 50 yards where the rifle outshines the pistol.
My .54 pistol barrel (for the same gun) is made from a piece of rifle barrel, has slow, 66" rifling and demands 50gr. 3F to shoot reasonably well - 2 1/2" at 50 yards. It is not as accurate as the fast, 18" twist .45, and requires a larger ball and thicker patch, harder loading.
As to a rifle's accuracy, even a smoothbore gun with only a front sight can shoot 1" groups at 25 yards for 5 shots. Rifles need to be tested and load developed at 50 yards and farther.