I have been looking for one of these for a couple years. I it is an DISC Original 50. But more importantly it is what I call a big bore 50. I have titled it a DISC Carbine. It only has a 22" barrel and will work perfect for me during Idaho's late ML season since we hunt in the timber that time of the year.
I made several changes to the carbine. First the ODISC stock had to go so I put a DISC Extreme thumbhole on it. It also came ready to shoot Orange plastic jackets, pulled that out and installed a Knight Western breech plug and a Lehigh #11 nipple. Installed a western style Lehigh/Knight bolt and a newer non C tool hammer assembly. The trigger is an original 3 screw Timney,
Then I put a Williams FP Peep sight on:
And the last thing was to install was a Williams #1690 Streamlined ramp with a 0.343 Williams Fire Sight and Williams Fire Sight Hood. And for me the green fiber optic is much more visible so I swapped the red one out for a green .060 rod.
Now to be able to get to the farm and get it sighted in... The snow is the big hinderance there...