That is Dandy .310 Cadet.

You can get everything you need to shoot it from Buffalo arms. They even had for a while the proper .310 cadet bullet mould by RCBS. I myself have the CBE .310 mould.

My current load uses Trail Boss powder.

This little cartridge as mention uses a heeled bullet. A .22 rimfire is heeled cartridge. The back of the bullet that goes in the case mouth is smaller than the driving bands the ar on the front of the bullet. Those band being the same diameter as the outside of the case.

Some bullet maker sell .32 H&R pistol bullets without gas check as .310 bullets. Cartridges loaded with these bullets often won't chamber and the advice is to shorten the case.

That will work. but the advice is bad. Find a proper .310 bullet first. Don't shorten cases unless you absolutely must.

Some of these guns have been reamed to take a 32-20 cartridge. They are usually marked as such.

If you have one of those you will find .32/20 not particularly accurate. the 32/20 uses .312 bullet. The groove diameter of the .310 Cadet is .321.

Over the years a number of people have swore there gun's bore is .316. I have asked number of people to send me a slug and they have always measured .321. This gun has tradition odd number of rifling an people do not know how to measure it.

Don't get discouraged by what I am writing, this is a fairly simple cartridge to load and shoot. But there are some things to learn.

Now that you have one of these, you need to look around for a Cadet in .297/230 Morris.

Now there is some fun.