Centaure Richards-Mason Conversion

# The Challenge or why the Richards-Mason is different

# The Italian Connection

# The Making of the Centaure Richards-Mason Conversion

# Decisions

# Range Report & the Important Little Details


The Challenge or why the Richards-Mason is different

Everybody likes challenges now and then. Karl Nedbal and me included. Therefore, we agreed on the next Centaure conversion project on August 22, 2008, the day the Thuer came home. We agreed that the next Nedbal Centaure conversion will be a Richards-Mason Army.

Compared to the Centaure Richards and Thuer conversions the RM Army is a different animal, see below pictures of an original.

Knowing Karl a bit better by now I am aware that he prefers the graceful lines of Thuers and Richards over the functional ones of the RM: their clumsy barrel lug or the sizable gap between conversion ring and cylinder might optimize the function but do not look sophisticated.

Original nickel plated Colt 1860 Richards-Mason conversion: note “S” shaped barrel lug

Converting a Centaure into a Richards-Mason is challenging but in other ways than the Richards or Thuer. The Centaure frame assembly can be used with some specific modifications like in the previous conversion projects. Lathing a new cylinder is no big deal after the Richards experience. The critical issue of this project is the barrel with ejector housing. Back then the barrel was not a leftover percussion part but purpose made without slot for the loading lever. The breech side of the barrel lug was straight and not cut for the loading slot either. It has the “S” shape typical for the RM Army conversion or the Open Top.

Same principle applies to the ejector. Consequently, the C&B barrel of the Centaure was not suitable for the conversion but a creative and financially feasible solution was to be found for a RM barrel assembly.

Centaure Richards-Mason Conversion

Project Outline

Base pistols

RNMA 1st variation, 3rd sub-variation #6176


8" made from semi-finished Uberti barrel, optimized "S" shape lug contour

Barrel marking



.44 Colt inside lubed (liner, .429 rifling groove diameter)

Ejector housing




Conversion ring

gated, Richards II type

Conversion cylinder

newly lathed conversion type, Centaure proprietary naval scene engraved


altered C&B type from Centaure

Gate spring



Centaure (steel, no toe on butt for stock)


Centaure (brass)


nickel plated

The previous owner of #6176 seemed to have taken her through the paces only once 1966 after the purchase. It appears that he thoroughly cleaned barrel, chambers and the outside of the gun after that shooting session and stowed her away. After I got her she was completely disassembled for a total body check. This is my standard procedure with a new gun. And yes, you guessed it. A thick layer of oily black crud mixed with some nice spots of soldiers’ gold (rust) in lock, piston holes, chambers, inside the grip.

RNMA #6176 1st variation 3rd sub-variation after purchase and proper cleaning: base gun for the RM conversion

But no - and as expected, no harm done: most of the grunge I could wipe away, some needed penetration oil but after my cleaning session she was technically and optically as good as new, see above. Thanks, Belgian steel makers for your hard steel and Fabriques d’Armes Unies de Liège (FAUL) technicians for your fine heat treatment and polishing jobs. You made my day.


The Italian Connection

Pards & pardettes please, stay tuned and watch what is happening! Eventually I expect my Nedbal Centaure RM to look like this exquisite, nickel plated, cased original Colt 1860 Army Richards-Mason pictured below when Karl is done with her.

Had to be in Austria on some business November 8, 2008 and paid a visit to the master. He had already installed the newly lathed period arbor with separate big grease groove. The slot for the wedge was not cut yet, the flat RM conversion ring was roughly contoured. As you can see, the spring-loaded loading gate works picture below right. Through their German distributor HEGE in Messkirch the friends at Uberti in Gardone had supplied a semi-finished and unmarked RM Army barrel with a bore in .44 Colt caliber, i. e. .429 in dia. Thanks a lot to Suzanne Webb & Giacomo Merlino of Uberti and Dr. Waldemar Gorzawski of HEGE.

The barrel came milled to accept the ejector housing. But it was also of the Uberti conversions standard beefed-up kind.

RM conversion ring before contouring, new arbor installed (left), loading gate open, periody correct external spring (right)


The Making of the Centaure Richards-Mason Conversion

To bring the measurements in line with an original RM Nedbal carefully cut a slot from the breech-end of the barrel to the hole for the ejector tube screw: parallel to the center line of the bore through the arbor hole and the slot for the wedge. He then pressed the lug together to the right height, welded and polished the slot, and re-cut the arbor hole to round shape to house the square tip of the new arbor. Next he will have to open up and re-shape the slot for the wedge, to further re-contour the barrel lug and remove some material off its beefy sides, and drill holes for the two barrel pins.

Holes for barrel pins need to be drilled in lug (left), welded and polished slot right and left from slot for wedge almost invisible (right)

November 17, 2008, Karl Nedbal calling: “The RM is almost completed except for test and proof firing including sight adjustment, and some cosmetic finishing touches like proper contouring of the barrel lug, engraving the Centaure barrel marking, embossing 44 CAL into the trigger-guard, and finally the nickel plating”

Almost completed, ejector housing and newly lathed conversion cylinder installed but barrel lug still with “Italian” contour



In addition he mailed more pictures but asked for 3 decisions to finalize the RM conversion:

#1 finish of the screws: nickel like the rest of the gun or fire blue?

#2 finish of the trigger guard: nickel plating or leave the brass yellow as it is?

#3 shall the serial be applied to the bottom of the barrel lug? Nedbal would have to make special dies for that purpose because Centaure digits look somewhat different.

Master Nedbal & the Centaure RM (left), Centaure proprietary naval scene on cylinder 44 CAL on trigger guard (right)

This pistol shall be as period correct as possible. Therefore, these were questions for the initiates in the USA. Karl will have to wait till I have them researched. I posted a query in the CAS-City STORM forum. Fox Creek Kid’s immediate response brought the issues into historical perspective and I mailed my decisions already the next day. Thanks a lot, FCK.

Nice pattern at 25 meters...thanks to the tall front sight...(left), …POA = POI

ad #1: nickel plated or blued screws would be PC. I go for nickel like the rest of the gun, looks more elegant,

ad #2: nickel plating of the trigger-guard is the way to go,

ad #3: the barrel needs to be serial numbered to the gun, i. e. extra dinero is requested for the dies.

Loading gate numbered to pistol (left), period correct external gate spring (right)

Vienna proof mark, serial numbers on trigger-guard, frame and barrel (left), further proof marks, Nedbal’s NK stamped under barrel (right)

As with the previous two Centaure conversions Nedbal approached completion of this new project with remarkable speed. But in December 2008 there was an unexpected set-back: his free-lance engraver decided it was time to move on. So Karl had to find a new one that would meet his quality. Which meant some delay.

Ain’t she sweet? Impressive 8” barrel RM Army, period correct nickel plated screws, new high front sight (picture courtesy Terushi Jimbo 2012)

However, on March 10, 2009 came the message from Vösendorf: “I’ll test fire her during the next few days to adjust the front sight, then have the pistol proof tested and finally nickel plated.”

To bring the baby home it was time for another long weekend in Austria . April 30, 2009 was the day of truth, when I saw Karl Nedbal in his shop in Vösendorf again, to inspect the finalized pistol, to handle the test fired and proof tested Centaure Richards-Mason conversion for the first time.

Regarding the machining and finishing process of the Centaure RM I like to share two observations of Nedbal here:

# the steel used for the Italian barrel is notably softer than the steel of the Belgian parts (frame) but also compared to Belgian barrels machined and contoured for his previously made Centaure Richards and Thuer conversions. This adds to the discussions in BP and CAS forums elsewhere regarding the comparative hardness of steel used in Italian and Belgian made cowboy guns.

# nickel plating of the Italian barrel proved significantly more difficult compared to the Belgian steel made parts (frame, back-strap, wedge, etc.) and the newly lathed cylinder (I am not a metallurgist!). The professional plating company involved needed a couple of goes until they could finally deliver an esthetically acceptable barrel.


Range Report & the Important Little Details

Broke some more paper during relaxed shooting on May 6, 2009 at the local indoor range (below).

Targets engaged from 8 (left), 25 (center) and 15 meters (right), after too much coffee

I appreciated her crisp trigger pull. Despite the 1960’s inherent pointability this cowboy had some problems aligning the high gloss front and rear sight: old weak eyes, too short arms and way too much coffee, ha, ha.

Slightly recessed chambers & 3 digits of serial number (left), new two-tooth hand of RM (center), conversion hammer made from the C&B hammer (right)

Complete disassembly after the range time revealed again Nedbal’s strive for the important little period correct details that lighten the heart of the initiates: the Centaure C&B revolvers use a single tooth hand like the originals from the 1860s. In this RM conversion he installed a newly made, period two-tooth hand with leaf spring. Mandatory proof, caliber and inspector marks of the Vienna Proof House in addition to his NK stamp were applied to the breech side of the newly lathed conversion cylinder. Equally important, however, the chambers are slightly recessed and the last 3 digits of the serial number, 176, were embossed there as well.

Barrel marking: original Centaure percussion barrel (left), Italian conversion barrel with Belgian marking engraved (right)

Did I say I am enthusiastic?

Triplet of Nedbal Centaure conversions: Richards (top), Richards-Mason (center), Thuer (bottom)


WDN/June 21, 2013

© 2007 Wolf D. Niederastroth