Interesting rifle and chambering

[Forrest Halley]

I bet there was two rifles.

I'll bet you're on the right track. With something like that being so pivotal in the show, I'd lay odds they had four or six of them.

 

[sestoppelman]

I am sure they had more than one to work with. Its my understanding that the rifles used mostly were in fact El Tigre Spanish rifles and not real Model 92's.
The rifles were of course modified and the show made no secret of that, there were episodes that showed Ol Lucas Boy working on his trip lever.