Wow - Justforthefinofit,
I had the EXACT same issue with a 56-50. I had to send it to ArmiSport repair center. Here's the address:
6785 W 3rd st.
I can't find the number, but I'll try to find it and email it to you.
According to the invoice they had to rework the carrier. Of course the parts list doesn't list a carrier - I think they're talking about the upper block, but am not sure. Does it cycle all the way down on the down stroke? Might try and see if the follower pushes the round up far enough for the upper block to catch it.
I additoinally had to do a LOT of work myself to get it smooth. See this post: http://www.cascity.com/forumhall/index.php/topic,38682.0.html
It took 6 months to get it back. Some have reported it taking more than 8 months to return.
You might try to return it to where ever you bought it, although I had no luck doing so with Cimarron.
Good luck sir, I wish you the best. - Pvt Greg