I agree with almost everything Ruark (wouldn't have anything to do with Robert Ruark, would it?) said, but here's an item here that deserves comment.Ruark wrote:With a barrel that short, a TINY fraction of an inch in movement - say moving it slightly when you pull the trigger - can move the impact point several inches or more.
A two-degree horizontal barrel shift is exactly the same degree of shift whether I'm shooting a .32 ACP Seecamp or a 6" 1911 longslide. The barrel is a straight tube. From the point of axis rotation, a two-degree shift is the same no matter the length of the barrel.
Put another way, if you were to take two guns in every way identical except that one had a 2"-barrel and another a 6"-barrel and were to position them in identical vises in exactly the same way, simultaneously rotating the vises to the same angle would result in exactly the same change in point-of-aim. The gun's inherent mechanical accuracy will affect point-of-impact, but the axis-rotation of the barrel will result in an identical point-of-aim.
What, in general, makes small guns more difficult to shoot well is the sight radius, mass, trigger, and grip/ergonomics.
Little tiny guns have little tiny grips and a short backstrap-to-trigger distance. That makes using them more difficult for anyone with medium-sized or larger hands. Even people with small hands can have difficulty with pistols that force the pinky-finger to grip air.
The small size of pocket guns necessitates that the number of moving parts be kept at a minimum. That means the only practical trigger is, generally speaking, a heavy, long-throw DAO. That's true with snubbies, and with most everything the size of a SIG 238 or smaller. Even the SIG has an 8-pound pull.
Many pocket guns weigh in at less than a pound. A Desert Eagle .50 AE weighs 4.4 pounds. Poor trigger control affects a 15-ounce gun proportionately more than a 4-pound gun. Thank you Isaac Newton for your Laws of Motion. But if you have excellent trigger control, you should be able to surprise-break the trigger the same no matter the gun in your hand.
Sight radius is what it is. My Seecamp .32 has no sights at all; it's designed for the purpose I use it: a 0-10ft BUG. Sights on a Kel-Tec P3AT have a miniscule sight radius. A government-size 1911 has a sight radius twice that of a P3AT. A rifle with iron sights might have two or three times again that 1911's sight radius. The longer the sight radius, theoretically the more accurate the firearm. Theoretically because, thank goodness, rather than trying to extend rifle lengths to umpteen feet for a humongous sight radius we were smart enough to invent sophisticated optics. The current record for a sniper shot is 2,657 yards (1.51 miles) by Robert Furlong using a .50 BMG McBros TAC 50. Optics are good.
Point is, shooting capability is directly transferable from a big gun, to a pocket gun, and back again.
If you have significant experience shooting, a pocket gun isn't hard to master. The basic skills--especially trigger control--are completely transferable. If you have little shooting experience, a pocket gun is going to be more difficult to learn to shoot well...primarily, IMHO, due to grip/ergonomics, trigger, mass, and sight radius.