440 Balls are for 45 caliber rifles and pistols.
The patches are about .10 to .15 in thickness. I guess you could tripple patch the round to make it work and be accurate. But I would not do it wiht one of my rifles unless starving. The poatch holds the bullet against the rifleing. Recovered balls do not have rifleing in them but an inprint of the patch fabric.
44 caliber revolvers use balls ,451 to .457. Go figure why a 44 uses 451 and a 45 uses 440 but best not to over think it.
The 50 uses a 490 ball. 54 uses 530 ball and 58 uses a 577 ball.
The difference of under sized balls for single shot pistols and over sized for revolvers is the loading system. In a single shot, you patch and ram, in a revolver, you have a lever that actually presses the ball into the cylinder, form fitting the ball, trimming a bit of lead along the way, causing your airtight seal.
Tower Naval Pistol
1848 Colt, note the loading lever.