Speak of the devil, and soon he appears! Finally, a topic on which I can expound!
Okay, it basically breaks down to this: Western weapons are almost impossible to find. Personally, I just bought a black Wingun in a 4 inch barrel. I will be bringing it to the operation on Oct. 12th if you would like to see it. Just look for the cowboy.
Right now, there really aren't too many places selling Colt Peacemakers. I searched for quite some time before settling on the wingun. I figured it would work and be practical at the same time. Granted, it's too hot for CQB but it will make a great addition to my U.S. Marshal loadout.
It kinda depends on if you wanna use it on the field. If you are just using it for a prop gun in movie, then a basic springer revolver will do you just fine. It might also work for cqb, but I wouldn't depend on it too much as they are pretty flimsy.
As for gas western revolvers, the Marushin X cartridge series or any of the western guns by Tanaka are supposed to be amazing. However, most can't be used with propane or green gas as it will blow the seals, as I recently found out. I bought an A&K Winchester rifle and after several games on propane, it blew a seal in the upper reciever. They are also rare and very expensive when you do find them. A good secondary option that doesn't cost as much as these are the Wingun series of revolvers, the "Dan Wesson" guns you mentioned. Everything I've read says they are pretty decent, and I will try to put up a review once I recieve mine.
If you ask Jon at SOGO very nicely, I'm sure he could probably get ya one! Like I said, I will be bringing mine to the game if you would like to see it.
After reading your post again, I would NOT use blanks in that revolver at all. That is a very bad idea, especially using them in a weapon not designed for them. It could blow up in your hand. With it being a CO2 revolver with shells, it should be pretty realistic for your film. It should work just fine without bb's in it, as long as you don't dryfire it for 1,000,000 rounds.
