buxtonguy---You can basically carry/shoot any combo ya want as long as the firearms are SASS/NCOWS legal. Some shooters post and whine about not 'being authentic', but neither are the Fruit of the Loom or Hanes underwear they have on or the $400.00 eyeglasses they have perched on their nose. Neither rifle or revolver need be the same caliber or exactly the same time period, ie. revolver that was introduced in the late 1850's and rifle that came from the 60's on up. Some shooters like to have combo's coming from the same time slot and both shooting the same caliber. I carry and shoot all kinds of combo's, depending on my mood of the day. The same rifle and revolver combo of revolver cartridges such as 44/40 made sense back in the day, but at a CAS type shoot when yer loading your firearms at a table and go to the line and shoot all that you've loaded (except say double barrel shotgun) you don't have to worry about going to the line reloading 38 Spec in your revolvers and 44 Colt in a rifle and keeping the rounds separate. Some like to shoot different calibers, some like to keep everything one caliber. I don't have a problem with a mix as I've shot all I have long enough I'm use to each one--all feel close to the same to me.
I've shot and carried short and long barrel revolvers for a long time crossdraw and have had no problem with either barrel length. As Abilene posted, a longer barrel is easier to draw crossdraw than from strongside. What ever ya feel comfortable with and are used to. Reference the arbor fix that's been posted, with my Colt style percussion and conversion style revolvers, I like using various thicknesses of brass washers vs a split washer. I bought a half dozen brass washers of various thicknesses at a hardware store and use whatever combination or of single ones that are needed to 'true' things up. Tried split washers but didn't care for them-not saying they don't work. I grease the washers when assembling the gun so they don't disappear as easily during disassembly. When taking the gun apart, the washers are either stuck on the end of the arbor or down in the arbor hole. The brass washers can be stoned down also if a thinner one is needed. Several years ago I bought around a dozen of the Dillion buttons that Pettifogger recommends for doing his posted Rx for arbor fix, but haven't got at that procedure yet--maybe this summer.