[Jen]

Buckshot. OK, I can remember that! My hubby is an engineer so he has described the shotgun shells to me in very precise language (I call it excruciating detail) down to the number and diameter of the lead balls inside the shell. And a whole bunch of other stuff that I don’t remember. LOL!

[Lurker]

Just tell the proprietor that you want some Buckshot for it. 20 gauge is usually #3 shot. You can find a chart with the relative sizes in this article which I wrote a while back.

Scroll down to the bottom of the page and you'll see a chart which illustrates the sizes and numbers of shot.

There's also a bunch of other information there you may find useful.

Hope it helps.

L