Jake's comment on my post
about 22
caliber pest control got me thinking.
Our Phoenix Arms 22 caliber pistol is called a
Long Rifle which I'm guessing means the barrel is rifled to improve
accuracy.
I stood 7 feet away and shot
a cardboard box that showed a pattern about 12 inches wide. What was
weird is right after I did that a rat scurried out of the weeds with
Lucy standing by to see what we were doing. Anna yelled "Get it Lucy!"
and Lucy caught it and crunched it within a few seconds. The term "Good
Girl" is a vast understatement today.
refers to the size of the 22 ammunition. there are a plethora of 22 shells. 22LR is the second smallest of them. See link for some detail http://www.chuckhawks.com/22_rimfire_cartridges.htm
The point of rifling is to make a bullet spin, giving it spin stabilisation to prevent it from tumbling. This only works when a tight-fitting bullet engages the grooves in the barrel.
So with buckshot it won't work. I'd suspect that you'd even get a greater dispersion than with a smoothbore barrel. And that seems to be the case.