I was at a gunshow and saw an over under caplock, 50 cal black powder rifle!

It was $250, don't know the brand but it was interesting looking.

anybody have one?

May have been what's called a "swivel breech" rifle.
If it was, each barrel on a swivel breech has it's own nipple...you fire the top barrel, release a latch, swivel the barrel around so what was the unfired bottom barrel comes up in line with the hammer and detents into position, latch it in place, and fire that second barrel.

I always thought it was a cool design...seems like it would be an excellent kind of rifle to have in .58 or .62cal for really big game...be a little hefty for still hunting though...

Nope, this was a fixed barrel,it had two hammers and two triggers.

CVA made them for a while, can't remember who made them before CVA. My buddy had one of each, on both guns one of the barrels bore was rough. <img src="/ubbthreads/images/graemlins/mad.gif" alt="" /> They shot OK, light and quick for a two shooter! <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />

There is one about 3/4 down the page at:
http://www.buffalobillsshootingstore.com/muzzleloaders.html

Interesting looking thing, eh