Centaure Infamous “Mystery” Conversion: who needs an 1860 Army conversion cross between an Army barrel with cool looking barrel lug of 1861 Navy conversion profile, on which a Richards-Mason-type ejector housing is mounted, and a RM cylinder & frame assembly with a Richards “saddle”-type conversion ring for good measure? Exactly, every household should have at least one. Because less than a dozen only are known today from yesteryear, probably made South of the border in Mexico, according to the conversion bible of the late R. Bruce McDowell, esquire.

#11691 from 1972

When Karl Nedbal phoned December 31, 2008 with an update on the Centaure RM conversion we agreed that this is going to be the next project. Above 1972 production run of the mill RNMA #11691 is the candidate for

Colt 1860 Army “Mystery“ Conversion this somewhat exotic conversion. The project was kicked-off April 30, 2009, the day the Richards-Mason came home. I will report about the progress as usual…

It was also agreed that Karl would not dash ahead at his usual pace of three months for the completion of a conversion, but take his time with the Mystery conversion. Here is what we have November 9, 2009, see pictures of the progress below. Nedbal had

# reshaped the 1960 Army barrel lug like one of a Colt 1861 Navy Richards-Mason conversion,

# plugged the slot for the loading lever in the barrel lug,

# installed the RM-type ejector housing.

# Although the “S” line on both sides of the lug is now more pronounced in true 1860 Colt-fashion no harm was done to the Liège Proof house acceptance marks on its left side during this operation (below picture),

# he removed the famous “Centaure step” where frame and barrel lug are meeting.

While the original Belgian arbor from 1972 is still in place

# the right side of the recoil shield has been opened wide to make room for the internal spring loaded gate of general RM Navy 1861 outline, just a might larger.

# For a PC installation of the Richards III type conversion ring of “saddle” design the master will have to attach it to the recoil shield by 2 screws. This required working on the two notches for the shoulder stock and welding them shut. He then contoured and finished that area to shape…now this is no longer a RNMA frame…

…but this little operation transformed it into a Civilian frame, see above and below. Neat little job, isn’t it?

Regarding the finish of the Mystery conversion we have a change of the original plan which called for nickel plating. After the RM experience, however, it is going to be Nedbal’s traditional rust blue. He will make every

effort to maintain the pretty factory case colors of the frame. November 14, 2009: the loading gate is shaped and installed. Please, note the important tiny details of this conversion ring: it has this enlarged section at its base to straddle the frame. Flares out on both sides where it meets the frame. December 3, 2009 and the beat goes on: Nedbal is approaching completion of the Mystery conversion. The conversion cylinder is already milled to specs by now. But Nedbal had to remove a small layer of steel from the forward area

of the frame…because for reasons unknown FAUL had lathed the original C&B cylinder of #11691 with a diameter that is ca. 1 mm less than what is the norm (!), and had adjusted the position of the arbor in the recoil shield accordingly. In other words the overall height of the barrel lug is smaller than those of other Centaures.

Conversion cylinder lathed, ratchets cut…

...and cylinder installed

Dec. 7, 2009 more news from down range the Mystery front: the cylinder is completely done now. This #11691 is turning into a glorious PITA, however. The technician back then at FAUL’s had cut the slot for the hand in the recoil shield too far off center compared to the original. Therefore, it will engage only half of a ratchet tooth. But the teeth of the conversion cylinder have only half the width of what is needed for reliable engagement, due to the recesses for the cartridge rims in the breech side. To correct this Nedbal opened up the slot towards the center for proper functioning and made a new, wider hand (same as for an original). This is one of the challenges the master needs from time to time to maintain his sharpness I reckon…

December 15, 2009: notches are cut into the cylinder and Nedbal test-fired the Mystery conversion for the first time. The pistol will be transferred to the Vienna Proof house mow for proof testing before the finishing tasks can be completed.

January 30, 2010: the deed is almost done, see pictures below. The Mystery conversion has passed the Viennese proof testing procedure and Nedbal’s contract engraver has applied the naval scene with the legend

NEW MODEL 44 between the scene. The barrel marking CENTENNIAL TRADE MARK “1960 NEW MODEL ARMY” has been maintained (picture below).

She is now ready for the master’s finishing touches: installation of the .429 diameter liner for my .44 Colt inside lubricated bullets, adjustment of the sights to hit POA and finally the rust bluing of the barrel assembly, new cylinder and other formerly cyanide blued parts.

WDN/February 12, 2010

© 2007 Wolf D. Niederastroth

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