25 rem and a few from the coffee can

I think the 380 rimmed is British?
The 38 Colt is “New Police”?

25 rem (base case for the 6.8spc)

Your .38 S&W cartridge is actually Canadian, not British (although both United Kingdom, of course). “DC” is “Dominion Cartridge.” The .38 Colt NP is “New Police.” It is basically the same as .38 S&W, just with Colt’s appellation for that cartridge. The rimfire “U” cartridge, which from the photo, not being a rimfire guy, I can’t tell the exact cartridge type, is from Remington-UMC using the “U” headstamp.

John Moss

Rimfire looks to be a .25 Stevens Short

DC 43 .38 is as John says, from Dominion Cartridge, Canada. It is what is correctly called Cartridge, S.A., Ball, 380inch, Mk.II

John, British= United Kingdom of England, Scotland & (Northern) Ireland.
Dominion of Canada was part of
British Empire, ( now British Commonwealth of Nations) but with Independant Sovreignity.
( although sharing HM Q.E II as Head of State…as do Australia, NZ, etc.).
Excusable error…1776 and all that.
Doc AV
Republican down under…
Keep up the fight against Covid-19.