Reflections on Centaure Conversions & the 1871-72 Open Top or the Rambling of an Old Cowpuncher:

“You can never have enough 1860 Armies” voiced a wise US pard and he is right. Like him I enjoy the graceful lines of this great cap & baller and add…”particularly as a period correct quality conversion shooting smokeless inside lubed .44 Colt cartridges”.

2 modern .44 Colt cal. RM Army conversions: top Centaure RNMA #6176 converted 2009 by Nedbal, bottom Uberti #X02711 assembled 2002

This is going to be a personal and very subjective page with a few drops of semi-scientific window-dressing. So shake well before swallowing. If you want a modern made Colt Army conversion these days it seems you only have 3 options:

#1: have one custom made by one of the few conversion artists. At your request they will convert the C&B repro revolver of your preferred manufacturer. What you are getting after a few months is usually a period correct, esthetically pleasing display pistol, or a shooter or even both. Of course, this will all depend on your briefing, the responsiveness of the gunsmith and the dinero you are prepared to spend.

#2: do-it-yourself using a commercially available drop-in cylinder with/without loading gate on your replica. If you are technically talented you have eventually a functional shooter resembling a Colt conversion from the 1870s … from a distance.

#3: when in a hurry buy a conversion pistol made by a reputed cowboy gun manufacturer. You’re a getting a very functional shooter “on steroids”* with factory warranty.

*respectfully adopted quote from Michael Venturino!

Front view of conversion cylinders Uberti (left), Centaure (right) after some shooting fun

Top view of same conversion cylinders: note gas ring of Uberti compared to PC Centaure

Regarding option #3 and to the best of my knowledge currently only Uberti in Gardone/Italy, subsidiary of the Beretta folks, makes Colt (and Remington) clones of conversion pistols or the Open Top in various calibers, grip and barrel configurations. The other maker in that market was Armi san Marco. They dropped out of the race around the turn of the century after quality issues. I own a few of these Uberti conversions in the modern inside lubed .44 Colt caliber and love them. Why? Because they are rugged and reliable shooting irons. I used a pair of their long barreled Open Tops with Army grips as main match pistols during the 2008 season. They worked well for me. My 2002 vintage Uberti Richards-Mason Army and Richards Transitional (RII) of 2003 production are getting their regular diet of my light CAS nitro loads behind 200 grainers.

1860 type pistols of quality makers hit what you are aiming at … once you have bottomed out the arbor and adjusted the sights to proper height. Although these Ubertis look like C&B revolvers converted to fire cartridges they are actually constructed as cartridge firing pistols for regular loads (no P+, please!), hence their beefed-up frames, cylinders and barrels. These strengthened parts will not interchange with the respective C&B revolver models. The steel used in the making of these conversions is harder than the alloy of their C&B brethren for a reason. Uberti is probably well advised to stick to that concept of beefing-up critical parts, using harder steel like for their SAAs and state of the art production technology. That provides for conversions and Open Tops that are considerably stouter than the originals from the 19^th centaury which in turn keeps the customers happy and the lawyers off their back. In addition it provides a simple platform to make these pistols in other, possibly more powerful but not PC calibers like .45 Colt or .44 Special. However, given the options available to own a modern, hard steel and quality made 1860 model conversion revolver with measurements of a

Comparative barrel view Centaure RI (left) vs Uberti RII (right)

Civil War period Colt Army with due respect I will be choosing the Centaure customs conversion.

How do measurements of modern 1860 cap & ballers or their conversions compare to originals? This is the time to ask which repros are close to the specifications, to that gold standard set by the 1^st generation Colt Army. Are our measurements of the 1^st generation and period conversions within the ranges provided by R. Bruce McDowell in his “conversion bible” A STUDY OF COLT CONVERSIONS AND OTHER PERCUSSION REVOLVERS? What is the impact of production tolerances back then and today?

To answer these questions for C&B and conversion pistols alike in a reasonable way measurements were taken in a standardized manner with digital calipers. This task could be accomplished within a short period of time thanks to the help of the FROCS community

around the globe. Below are the critical areas measured and eventually compared:

# front diameter of the cylinder

# rebate diameter of the cylinder

# overall height of the barrel lug

A healthy human eye will note differences of ca. 0,5 mm/.02 in in size of comparable objects. That is the working assumption. Deviations within these ranges are considered

“regular production tolerances” (RPTs), or not significant. Deviations beyond RPTs are considered significant. They are printed in bold face type in the tables below. The numbers in brackets in the Serial Number column indicate the number of pistols per manufacturer measured. Numbers in that same column without brackets are serial numbers of individual guns.

When more than 1 gun was available from a manufacturer measurements were averaged, to take into account production tolerances. Ranges of the measurements are provided as appropriate.

Measurements of 1^st gen. Colt Army pistols are printed in blue/red bold type. Blue * marked data is from McDowell’s book.

Deviations above RPTs are what we refer to as “beefed-up”.

This 1860 Armies data (left) indicates that most measurements from modern C&B 1860 model revolvers are within RPTs if we accept that only 3 originals were at hand for reference. If that is OK one should also note the very close tolerances

of 1^st gen. Colts! Further comments regarding brands or manufacturers:

# Centaures front & rebate diameters are below RPTs

# 2^nd gen. Colts barrel lug height ranges are below RPTs

# 3^rd gen. Colt barrel lug height is below RPTs

# Euroarms barrel lug height is above RPTs

# Pietta front cylinder diameters are below RPTs

# Uberti front cylinder and barrel lug height ranges are below, the rebate cylinder diameter ranges above RPTs.

Thuer Armies: Only a small sample of 4 Thuers was available for measurements, 2 original Colts and 2 Nedbal conversions, see table below. Therefore, only a few careful comments seem prudent:

# The height of the barrel lug of the 2 original Colts is smaller than that of their C&B versions presented in the table above, and only just within their respective RPTs.

# The measurements of the 2 Nedbal conversions are almost identical. This was expected regarding their cylinders because they were copied from the same original. In addition some details:

# Colts’ front cylinder diameter is below RPTs # height of the barrel lug is above RPTs of Colt Thuers but within reference C&B originals!

Richards Armies: We are comforted that the specs of the 4 originals from the 1870s are within RPTs, like those of their C&B brothers. The Anderson, Centaure and Howell 2^nd gen. Colt conversions are within RPTs, whereas the Gren and R&D 2^nd gen. Colts are off in one measurement only, but the Uberti RII (they don’t make a RI) is pretty much beefed-up! Details regarding these significant deviations from the RPTs are listed below.

# Gren 2^nd gen Colt rebate cylinder diameters are below RPTs # R&D 2^nd gen Colt front cylinder diameter is below RPTs

# beefed-up Uberti RII in all 3 measurements!

Richards-Mason Army: Here we only have the McDowell data for reference. Unfortunately, he is providing no measurements for barrel lug height and no data of original RMS could be provided by any of the FROCS. Here is what we got:

# While the forward area of both Centaure & Uberti RM cylinders are beefed-up # the Centaure is OK in the other two measurements. In other words Uberti is beefed

up in all 3 departments!

So, where is all this measuring and comparing getting us? These are my subjective conclusions:

# According to our sample the majority of 1^st generation Colt 1860 Armies was built with close production tolerances. Contrary to opinions voiced elsewhere, however, this applies to their clones and re-issues as well.

# If the objective of your conversion project is PCness of a safe, reliable shooting iron the quality of the steel used for the base gun & newly manufactured conversion barrel/liner & cylinder becomes THE key issue.

# Centaures are made of harder steel than Italian C&B pistols.

# PC conversion pistols are not available off the rack, only custom made!

# To me this page helps to rationalize my prejudices and preferences vis-à-vis the best wifey of them all to get financial funds sanctioned for my Centaure conversions!

4 x 1860 model Army pistols (top down): Nedbal Centaure Richards #4079, Uberti Richards-Mason #02711, 2^nd gen Colt Army #US0858, Uberti Richards Transitional #04444

“Yes we can”: Some consider the M 1871-1872 Open Top the queen of the Colt conversions. With the experience already gathered from other Centaure conversion projects it appears that the way is now paved for the making of a Centaure Open Top with Army grips in .44 Colt cal. using many original Belgian parts. Here is the shopping list and a rough outline of such a project:

1. original Centaure back-strap, grip and frame incl. small parts can be used. Frame needs to have steel plate welded to the lower forward portion to get one straight platform without the typical Army C&B pistol step, see picture below. A loading gate must be added. Hammer needs to be reworked and a firing pin added, similar to RM project.

Original Colt Open Top

2. Uberti steel trigger-guard needs to be mated to Belgian frame, back-strap and grip. 3. new conversion cylinder needs to be lathed from ordnance steel. No big deal for a conversion artist. 4. semi-finished Uberti barrel in .44 cal./.429 dia needs to be recontoured and fitted, see RM project.

5. new OT ejector housing needs to be made and mated to barrel, see RM project.

Compared to the previous Centaure Richards-Mason conversion this Open Top will have almost more Italian than Belgian genes.

Will I pursue such a project? May be, may be not. Certainly not before the Long Cylinders, the Mystery and the Richards Transitional are completed … & Karl Nedbal accepts the task … & last but not least the War Department permitting, of course!

WDN/July 10, 2010

© 2007-10 Wolf D. Niederastroth

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