need help 310 CADET

[bladeracer]

what's this logo?

IMG_0007a.JPG

A proof mark, possibly Birmingham Proof house?

[LawrenceA]

what's this logo?

IMG_0007a.JPG

A proof mark, possibly Birmingham Proof house?

I think you are right.
Looks a lot like the Cursive UPB under crown used from 19868 to 1925

[93x64mm]

The little cadet is not something to trifle with. They can give you a lot of grief so best find someone at your local range who has one of these little gems & start picking his or her brains! Not to put you off but these are heeled projectiles & from articles I've read is best to use regardless.
If you have any surviving factory ammo then mike these guys, if they shoot accurately them get a lend of a chronograph & measure their velocity so you can load appropriately. You'll may have a weight of projectile on the box so order a 'sample' pack(s) from Dave at CBE. Whatever works best, order a mould & go from there.
They are a labour of love & will test your mettle at reloading, when you get one of these going properly write all your notes down for goodness sake!
Best of luck