5.4 The Making of the Centaure Richards-Mason Conversion

Chapter 5 – Centaure Conversions the Next Level of the Evolution?

5.4 The Making of the Centaure Richards-Mason Conversion















The Making of the Centaure Richards-Mason Conversion

The Challenge of Why the Richards-Mason is different

Project Outline Centaure Richards-Mason Conversion

The Italian Connection

The Making of the Nedbal Centaure Richards-Mason Conversion


Range Report and the Important Little Details




The Challenge of Why the Richards-Mason Conversion is Different


Everybody likes challenges from time to time. Karl Nedbal and I included. The two of us agreed on the next Centaure conversion project on August 22, 2008, the day the Thuer came home. The next Nedbal Centaure conversion was to be a Richards-Mason (RM) Army.

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


D:\Colt 1860 Army RM Conversion\1-C6359d__72153.jpg

5.4.1_1 Left side view of original nickel-plated Colt 1860 Army Richards-Mason Conversion: Note typical „S“-shaped barrel lug (picture courtesy Collectors Firearms, Houston, TX, U.S.A.)


By now I know Karl a bit better. He prefers the graceful lines of Colt 1860 Thuer and Richards over the functional ones of the Richards-Mason. The latter’s clumsy barrel lug or the sizable gap between conversion ring and cylinder optimize the function. Surely, they do not look elegant and certainly not sophisticated.



Project Outline Centaure Richards-Mason Conversion


Converting a Centaure into a Richards-Mason is challenging. Compared to the Richards or Thuer, however in different ways. The Centaure frame assembly can be used with some specific modifications like in the previous Richards conversion project. Also, the milling of a new conversion cylinder is no big deal after the Richards experience. The critical issue of this project are barrel and ejector housing. Because back then the barrel was not a left-over 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 applies to the ejector. Consequently, the C&B barrel lug of the Centaure was not suitable for the conversion unless you were welding it to shape. Because that is how the U.S. conversion artists are tackling this. Neither Nedbal nor I liked the welding approach. A creative and financially feasible solution needed to be found for a Richards-Mason barrel assembly.



Project Outline

Project revolver

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 (R2) type

Conversion cylinder

Newly lathed conversion type with Centaure proprietary naval scene


altered C&B type from Centaure

Gate spring


Grip frame

Centaure brass triggerguard, backstrap with without notch


nustom nickel plated


The owner of #6176 seemed to have taken her through the paces only once right after the purchase in 1966. It appears that he thoroughly cleaned barrel, chambers and the outside of the gun after that shooting session and stowed her away. After her liberation she was completely disassembled for a total body check, my standard procedure with a new gun added to the herd. A thick layer of oily black crud mixed with some spots of soldiers’ gold (rust) covered lock, piston holes, chambers and was found on the inside of the frame, too.


D:\FAUL RNMA 1V 3SV #6176 Nedbal RM Conversion\1-FIL22498.JPG

2.4.2_1 RNMA 1st variation 3rd sub-variation #6176 after purchase and proper cleaning, project gun for the Richards-Mason conversion


But as I had hoped for and almost expected, no harm was done. Most of the grunge I could simply wipe away, some uncooperative spots needed penetration oil. But, after my thorough cleaning she was technically and optically as good as new. Thanks, Belgian steel makers for your hard steel and Fabriques d’Armes Unies de Liège (F.A.U.L.) technicians for your fine heat treatment and polishing jobs. You made my day.

The Italian Connection


Pards & pardettes, please watch the progress of this project! Eventually, I expect my Nedbal Centaure RM to look like below exquisite, nickel-plated, original Colt 1860 Army Richards-Mason when Karl is done with her. The original grips will stay plane wood, no sculpting was considered.


D:\Colt 1860 Army RM Conversion\1-IMG_0486__72136-001.JPG Right side view of original nickel-plated Colt 1860 Army Richards-Mason Conversion, sculpted grips, typical gap between conversion ring and cylinder, functional ejector housing (picture courtesy Collectors Firearms, Houston, TX, U.S.A.)


Through their German distributor HEGE in Messkirch, the friends from Uberti in Gardone had provided a semi-finished and unmarked RM 1860 Army barrel with a bore size for inside lubed.44 Colt cal. bullets, i.e. .429 inch rifling groove diameter. The barrel came milled on the right side to accept the ejector housing. It was of Ubertis regular beefed-up (!) size used for their conversion revolvers. Therefore, some contouring would be needed eventually for proper fit and historically correct contour.

Thanks a bunch, to Suzanne Webb and Giacomo Merlino of Uberti and my good friend Dr. Waldemar Gorzawski of HEGE for these arrangements.

The Making of the Nedbal Centaure Richards-Mason Conversion


Had to be in Austria on some business on November 8 2008 and paid a visit to the master. He had already installed the newly lathed period arbor with the separate big grease groove. The slot for the wedge was not cut yet, the flat, roughly contoured RM conversion ring was fitted, the spring-loaded loading gate attached already.


D:\FAUL RNMA 1V 3SV #6176 Nedbal RM Conversion\1-FIL12166.JPG Semi-finished Uberti Colt 1860 Army RM barrel cut with groove for ejector housing


To bring the measurements of the Uberti RM barrel 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, i.e. parallel to the center line of the bore right through the arbor hole and the slot for the wedge. He then pressed the lug together to the correct height, welded and polished the slot, and recut the arbor hole to round shape to bottom the new arbor. Next, he will have to open-up and reshape the slot for the wedge, recontour the barrel lug and remove some material off its beefy sides. Eventually, he will drill the holes to accommodate the two locator pins.


D:\FAUL RNMA 1V 3SV #6176 Nedbal RM Conversion\1-FIL22991.JPG Invisible: Welded and polished slot right and left from slot for wedge


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


D:\FAUL RNMA 1V 3SV #6176 Nedbal RM Conversion\1-FIL11873-001.JPG Almost completed: Newly milled ejector housing and conversion cylinder installed, barrel lug still has “Italian” contour with “S” curve too flat



In addition, Karl mailed more pictures but asked for three (3) quick decisions to finalize this Centaure Richards-Mason 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. Serial number stamped on the bottom of the barrel lug? Nedbal would have to purpose-make special dies because Centaure digits look somewhat different from the rest.

This conversion is supposed to look as historically correct as possible. Therefore, his three questions were for the initiates in the U.S.A., Karl will have to wait till I have the answers 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 could mail my decisions the next day. Thanks a lot, FCK. These were the decisions:

ad 1: Both nickel-plated or blued screws would be historically correct. I go for nickel like the rest of the gun, looks more elegant.

ad 2: Nickel plating of the triggerguard 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.


D:\FAUL RNMA 1V 3SV #6176 Nedbal RM Conversion\1-FIL12148.JPG Final check: Mster Nedbal and Centaure RNMA Richards-Mason conversion #6176 in his shop


As with the previous two Centaure conversions Nedbal approached the finishing line 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 standards. Which meant some delay. The all-clear phone call came on March 10 2009 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.”


D:\FAUL RNMA 1V 3SV #6176 Nedbal RM Conversion\1-FIL06976.JPG Test firing #6176 at 25 meters: Nice pattern thanks to the tall front sight, POA = POI


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.