converting the Italian Colt cap & ball to cartridge revolvers

Back about fourteen or fifteen years ago I found some new smokeless 38 S&W cylinders from a gunsmith. These were part of the old Legal Defender kits sold in Shotgun News to convert your Italian Colt to use cartridges. Next step was to fine some incomplete and damaged revolvers at some gun shows. I found an Uberti 1861 Colt missing the cylinder and loading lever and not working, later I found another Uberti 1851 Colt with the cylinder locked and wrench marks in an attempt to rotate it, missing grips and loading lever too.

I was able to restore these revolvers, making new ejector housings, recoil plates, loading gates plus replacing hands and bolts and making barrel wedges. I ordered brass ejector rod springs and SA mainsprings from EMF. Now these pistols shot alright but there is still the problem of firing a .358 dia bullet down a much larger bore. I decided to use hollow based bullets that I made up with a weight like the original of about 130 grs. these work with light charges of Unique, will try black powder outdoors.Attachment 104387Attachment 104388Attachment 104389Attachment 104390

They look pretty good...

Nicely done!
I remember those Legal Defender kits being advertised.
In addition to hollow based bullets, there is the option of heeled bullets, as well as sleeving the barrel to correct .38 cartridge dimensions.
Anyone interested might want to visit kirstkonverter.com and cartridgeconversion.com.

I know about the excellent Kirst products and have a new Kirst cylinder in 38 cal for the Colt 1851 should I find another incomplete revolver. S&S Firearms use to carry the line
of heeled bullets but long discontinued the molds.

The 1861 Colt has a slightly larger frame and when I made the recoil late, I had to make the firing pin and bushing off-set. Also had to make a gage to align the firing pin hole to the center of the primer and the cylinder to the barrel breech. It worked out on the second attempt (photo of the recoil plate of the 1861 revolver). The load gates were made from a round piece of stock then cut outAttachment 104400Attachment 104401Attachment 104402Attachment 104403

I'm in the process of setting up a Pietta '51 in both .38 and .45, using Kirst parts. Going to try HBWCs in the .38, see how they work, before deciding about installing a liner. Have a piece of liner on hand, if needed. The HBWCs are an smooth push fit in the .36 barrel, so with the hollow base, they should engage the rifling nicely.
Made a replacement ejector assembly for a hand made single action revolver (a Selby Webb .22). Folks might not appreciate there is a bit more to making one of these than meets the eye.
Acquired a basket case Centennial Arms 1860 a while back. This is one of the first repro percussion revolvers to reach the market, back in the '60s. It had a ruined cylinder pin, so I had to make one. Interestingly, the threads are Imperial. Started with a die makers bolt, machined it to fit the cylinder, etc. Cutting the slot for the wedge was the fun part.

I would recommend using hollow based bullets first in any of the conversions even if you have to make the hollow base yourself. I have had good results in my 1861 and 1851 conversions.

I have also used hollow base 452 dia lead in my S&W 1915 that was in 455 but rechambered to 45 Colt. Also made a shorter 45 Colt cartridge case tooAttachment 104438Attachment 104437

Anyone ever try to do the original method of slicing up the factory cylinder, and pinning/screwing a plate on the rear to make the thickness correct and then drilling through the whole thing?
Remember an issue of old west guns that had a short talk about a modern company post 2010 that did that for a special Patterson edition

You are correct, back in the post Civil War period when they (gunsmiths and Colt factory) started the cartridge conversions, they cut off the rear
of the cylinder and installed a recoil plate. Some had firing pins in the recoil plate while other conversions used the hammer firing pin. Your idea
is good only if you use black powder in the cartridge (example 38 Colt ) If someone chambers a smokeless cartridge in the repro black
powder cylinder it is not strong enough for sustained shooting. That is why I used the best smokeless cylinders available as both black and
smokeless powder can be used

thing is, the company in the 2010 + who did that Patterson conversion I read about, used the Italian percussion cylinders and made no specific requirements in regards to ammunition or not.

The Patterson conversion proof marks would indicate black powder or smokeless powder

never specified smokeless or black powder only.

and considering that the proof house would in theory test to the same strength. smokeless loads ARE supposed to stay in the safe range for the original laodings particularly in 32 and 38...

The Italian percussion proof loads would be black powder - that is all that is used in these percussion guns. As remanufactured to use cartridges, pressures should be kept at or below that level, as far as the cylinder and barrel are concerned. One additional factor with the cartridge conversions, that doesn't exist in the cap guns is backthrust against the breech face.
Anyone shooting a cartridge conversion isn't going to be hotrodding it, and there are smokeless loads that produce pressures well within the design limits of the guns.

I use Unique smokeless for indoor shooting and black powder for outdoor shooting. The 38 S&W case with Unique powder and a deep hollow base bullet of 358 diameter works out well in the 36 cal barrel. There is no requirement for "hot" loads just pleasant accurate loadsAttachment 104584

Attachment 105525Attachment 105526Attachment 105527

Pietta replica with BP proof markings. Barrel says .36 caliber. No markings, proofs to indicate it chambers .38 S&W cartridges. I don't know if its factory or someone else did the work. Any way its neat.

Very neat...

In the "old days" I don't think the Colt Patterson would have been selected for a cartridge conversion - but it is possible. Looks neat on the reproduction. Note the ejector rod housing is from a Colt 1851 as the slot for the wedge is not in alignment same for the recoil plate and loading gate. Looks like who ever performed the conversion did the cylinder just like the originals. turn down the rear to fit the recoil plate and chamber each cylinder. Hollow base 38 S&W lead bullets will work very nice.

I just fired my Uberti Colt 1851 that I had converted to 38 S&W and the hollow base lead bullets worked out very well at some 20 feet using a restAttachment 105534

That is an ambitious conversion. One of my books shows a modern Paterson conversion - real custom work.

I wanted a barrel with a true .357 groove diameter for my project. Took a '51 .44 barrel that bubba had messed up, and bored out the rear portion, cutting the barrel off flush. Sleeved a .357 barrel into this breech section. Haven't mounted a front sight yet, but it is ready for test firing.

Checked the reference to the Paterson conversion. It was done in Texas, and is in a museum in Oklahoma. Two reproductions of it have been made by RL Millington. Don't think the one pictured above is one of these, though. The original and the Millington repros have the grip frame with the flares at the front and rear.