This is an old thread, but maybe this will spruce it up a little. Besides, you never know when another new member will wander down these back alleys like I did.
I started shooting CAS with borrowed rifles, to see how I liked the game before I made the investment. And I watched others carefully to see what they were shooting and how things went for them. Those early experiences lead me to choose a '92 Chiappa Puma (after a false start with a Rossi '92) that I'm happy with. At this point, at least, it's the right choice for me.
Why did I choose the '92? First, because I noticed that in general '73 shooters had more problems than '92 shooters. There were more of them, to be sure, but even taking that into account, I observed that the '73 shooters were a small army of tinkerers, with lots of screwdrivers and funny tools, always having issues and fiddling with their guns, whereas the '92 shooters pretty much just got up and did their shooting. For my own part I managed to jam up every model I tried equally wel, until an old hand taught me to stop babying them and to cycle the action fully, and with gusto, yet smoothly. Even though that sounds contradictory, I learned to do that, and a lot of the problems went away. He opined that most of the time a lever gun stovepipes, it's due to operator error, not the equipment.
I also learned from experimentation that small details like cartridge length and bullet shape in the cartridges made big differences in the reliability of different guns, especially shooting .38 Special in a .357 rifle. And I tried everything I could get my hands on. Took up handloading so I could try different combinations that I couldn't buy off the shelf (and also to have real lead bullet cartridges to shoot when none were available at the dealers). One day another old hand showed me the "lever action rifle" .38 Special loads he shoots (.38 special brass loaded bullet high to nearly .357 overall length), and it all clicked in. Most factory loads are a bit shorter than the max design length allowed by the industry standard, which is 1.55" For example I just miked two name brands of .38 Special round nose, and one averages 1.46" long and the other is 1.49" That's about 1/16" shorter than they could be. And that 1/16" makes them feed less reliably in a lever gun, especially in one chambered for the longer (1.59") .357 cartridge. That's one of the secrets of why the older model "yellow boys" chambered for .38 Special seem like more relaible guns, as long as you disregard all the other issues they have. They're using length appropriate loads, so they load smoothly..
The second biggie is bullet shape. Flat nose round points are traditional, and seem to be the most common for CAS lever guns, but flat point conical (or truncated cone) seem to feed a little easier, and factory cartridges with that shape, such as the Black Hills Cowboy line, seem to enjoy a good reputation. I'm no Elmer Keith, but I've noticed that these little things do add up. I decided not to load all the way up to .357 length because it limits magazine capacity in my gun to 8 or 9 rounds, but loading to 1.54" with flat top conicals works like a charm.
And to give full disclosure, I'm not a high speed "gamer" and never will be. I just love the cameraderie and the "bang and clang" of CAS shooting. And I'm mostly shooting in competition with myself. I concentrate on trying to shoot clean matches and trying to betteri my previous stage times, so absolute maximum top speed is not even on my radar. Minimum equipment hassle on the range is.
So that's why I chose the '92.
And as always, your mileage may vary.