I've always wanted a Thompson. They would be a blast and you can still find 50 round drum magazines for them at gun shows.

However, the SKS cartridge is by far the best of the two for deer hunting, although I personally wouldn't hunt with either. The .45 acp is just not a deer hunting caliber, in my opinion, regardless of what firearm it comes out of.

If you have another means of for hunting, I'd make the switch. Having a good ol' tommy gun would be a blast.