Conversion Cylinder Ammo Question

[HappyTrigger]

Hey guys, I just acquired a Taylors' R&D conversion cylinder for my Uberti 1858 Remington and have some Winchester Super-X 45 Colt lead round-nose ammo (255 gr, 860 ft-lbs), and am wondering if I can use it in the new cylinder. The paper that came with the cylinder says to use cowboy ammo, 750-850 fps. Maybe I'm not quite sure what "cowboy ammo" means. Does it automatically mean black powder, or is it more about the size/strength of the load?

Sorry about the stupid questions but I'm a newbie just trying to learn.

[Daniel Nighteyes]

Sorry about the stupid questions but I'm a newbie just trying to learn.

This is actually a rather smart question, Hap.

The propellant charge in"Cowboy" ammo, particularly with smokeless powder, has been lightened considerably.  This is very important when shooting black powder pistols like the Remington, because they'll simply not stand up to modern loads.  The steel in the conversion cylinders is tougher, but in the R&D cylinders particularly, the cylinder walls are pretty darn thin.  They have to be in order to cram six .45 Colt rounds into the cylinder diameter.  Even then they have to slant the cylinder bores a bit.

So, I'd stick to "cowboy" loads that do NOT exceed the R&D listed maximums.  To do otherwise, IMO, is courting a major risk of ruining your whole day...

You will also find that the R&D cylinders' chambers are quite tight, so that 45 Colt rounds at the upper end of the spec limits won't chamber.  This can be rather, ah, amusing at the loading table...  .

My loads are a good bit less enthusiastic than the R&D max loads, and I'm gonna tame 'em down even more.