The Uberti frames are the same. I have both 36 and 44. The cylinders easily swap from one to the other. Older (over 20 yrs) Ubertis had a longer cylinder, same as current Piettas, so I have to watch the length for my older Uberti, as the cylinder gap is excessive with a newer cylinder. It works with a Pietta backplate on an Uberti cylinder. Kirst has a different length cylinder with the backplate the same, Uberti has a thicker backplate and the same length cylinder between the brands.
I have Kirst conversion cylinders for the 36's, BUT, be careful, Shooting a 45 Colt through a 36 bore is rough on the gun, don't ask how I know.
I have both Kirst and R&D cylinders for the 45 Colt, and they make a fine shooter out of the Carbine. It might be interesting to have a 36 caliber carbine to shoot 38 special, but a HBWC might not be stabile at longer range, depends on the rifling twist.
