Deacon, I am going to weigh in on your rifle choice, as I had a similar choice once.  My 1st CAS rifle was a Winchester '94 Trapper in .45.  What a horrible gun for this game.  Maybe better than a Big Boy?  But at the time, it was the worst.  Due to the design and the 9 round limit.  So my next gun was a Navy Arms stainless '92 in .45.  Stainless because I wanted to start shooting BP and thought you needed stainless (right now, I own zero stainless guns).  It was a huge step up from the '94, even though the action wasn't real smooth even after some work.  I did shoot BP in that one for a year or so, but then I got my 1st toggle rifle, a 44 Spcl 1866.  That was a straight wall case also, really no better for BP than the .45, but the action made it so much nicer to shoot that I never shot the '92 anymore and sold it whenever I got a '73 in .45.  Yes, the '66 needed more cleaning after shooting BP than a dash caliber, but it always made it through the matches, just needing a spritz of moose-milk or plain water when the carrier would get sticky.  This would usually be right after I finished a stage, never in the middle of a stage.  That '66 never had a short stroke, but I did the "poor man's" action job on it and it is quite smooth.  My concerns back then were not the functioning of the rifle, but that the bullets would have enough lube since I was relubing smokeless bullets with their tiny lube groove. Sometimes I would need to give the bore a swab mid-match.  BP subs would eliminate that, though.

So, I'm going to say go with the '66 in your choice, simply because it is more pleasant to shoot than a '92 IMO.  The fact that it will get dirty and need cleaning is just part of the game.  Most of my BP main match shooting now is .38's in a '73, even though I do have a '92 in 32-20 which needs less cleaning.

Mako, no, the question is inane.  I don't make it habit of listing my guns on a public forum.   Who cares what others shoot?    It's often a matter of what a person can afford, likes, has available to them or appeals to their sense of history, or any number of subjective reasons.  As a matter of fact, I do shoot percussion pistols, 36 caliber ones to be not quite specific.  Been shooting one of them since before there was a Frontiersman category in SASS, back when all we used was a single pistol..., well, before there was a Frontier Cartridge category, in fact.  So I've shot in the rain with percussion pistols many, many times.  I shoot a 45 Colt rifle, which specific one is a matter of whim on any given day... I shoot a side-by-side shotgun, 12 gauge, and again, which specific model is often a mystery, even to me, (although my current choices are down by one, it being in the shop for repairs), so it's either a hammerless with 20" or 26" bbls, or maybe the 26" or 28" hammered. 

Griff,
Your answers are inane. 

It's not "trivia"..  Do you shoot Rugers, Colts, USFAs, Ubertis, whatever?  What caliber?  I am assuming you shoot a Uberti made '73 in 44 WCF.  You've made no reference to what scattergun you shoot.

And, since you don't have wet weather guns I can pretty much guess that you don't shoot loose powder percussion revolvers.  Capped and holstered they are fine, before the loading table where they are capped I have tried plastic bag covers with mixed results.  The real problem is loading powder under an umbrella or poncho and keeping the cones dry.  A lot of clubs won't allow you to retreat to a truck or even a covered pavilion that is not actually on the range line.  I don't blame them, it is a range officer's nightmare to have people handling firearms off of the line and behind everyone.

If you don't want to tell us that is fine, you don't have to participate.  But, we have no idea what your categories and inventory is.  I don't think the gun snatchers are worried about your cowboy guns to the point they will hunt us down for our 19th century "assault weapons". 

  Mako

In this video Popcorn Kelly models the impact collapsing categories would have had on two matches, the first a 140-shooter match and the second a 70-shooter match based on SASS guidelines of collapsing unprotected categories with less than three shooters in them. it may not have the impact some think it does. It is important to understand that these results described here may not translate to other clubs or matches. Each club needs to do what is best for them and their members.

Round nose bullets in a tubular magazine:  can a person get away with it, or is there likely to be a detonation?

With all due respect to previous answers...  As one who has successfully used a particular round nose bullet in a .38 special loading in CAS since about 1985, I'll say it depends:

1) on the hardness of the bullet;
2) how "round" the nose is, which can vary greatly;
and 3) velocity.

You also have to recognize that bullets in rimmed cartridges don't sit flat in the magazine, so even a flat nose can have a corner in contact with the primer.  It is inertia that will set off primer, exacerbated by the weight of the column of cartridges in the magazine, how many times a particular primer is struck before it collapses the onto the anvil, which can be dependent also on the hardness of the primer.