Ted (Kevin Costner) comes home from China to 1920s Canada and he's trying to smuggle guns and trying to get people to give him either guns or money or both, and his younger brother is involved in smuggling liquor to the U.S., and then there's something about socialists. Go read the summary on the IMDB--I wish I'd read it before watching this, because I really didn't get all that from watching the movie 3 times. I certainly didn't catch that he was in love with the night club owner--I thought that was just sex and business.
The 20s atmosphere was excellent, and it's odd, but the whole confusion thing just fit with the film as a whole. There was very little dialogue, and what there was was terse. The scenes were mostly dimly lit, and if I'd paid very close attention, I could probably come up with what the roulette scenes symbolized besides the obvious all-or-nothing risks Ted was taking. (Or maybe it's not that deep, and I got it already.) All that fit together very well to make a whole. It's just that it's a period piece--a character study, where the character in question is 1920s Canada--and I prefer more story to my movies.
The Gunrunner strikes me as a movie to have playing in the background on a big screen TV while you're hosting a 20s party. If nothing else, a young Kevin Costner is definitely pretty.