5.7 A Bucket Full of Centaure Long Cylinder Conversions

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

5.7 A Bucket Full of Centaure Long Cylinder  Conversions
























A Bucket Full of Centaure Long Cylinder Conversions

What is a Long Cylinder Conversion (LCC)?

Next of Kin – Colt Open Top 1871/72

Introducing Klaus Mumme – Master Gunsmith, Cowboy Action Shooter and Conversion Artist

The Making of the Mumme Centaure Long Cylinder Conversions

Proof Testing and the BATF

The Day of Truth

Range Report #1

Range Report #2

Growing Pains

Ready for Action – at Last

Winter 2011/12 – Update from Downrange

Excerpts of the Testers‘ Report

The Herd Keeps on Growing

Centaure RNMA #12270

Centaure RNMAs #5590 and #11681 – # 5,5″ Barrels

Centaure RNMAs #7956 and #7957 – 6″ Barrels

Centaure RNMAs #12867 and #13859 – 4″ Barrels




What is a Long Cylinder Conversion (LCC)?


Bob Millington’s ( 3rd generation Colt 1860 Army Long Cylinder Conversions (LCCs) introduced by Dennis Adler in his book COLT SINGLE ACTION FROM PATERSONS TO PEACEMAKERS should have attracted more attention. Because this rustic as well as economical alterations of mostly Colt 1860 Armies to breechloading revolvers for the poor cowpokes back then looked like another interesting proposition for a conversion project.

The assessment of the late Bruce McDowell that originals were probably made south of the Border after the Civil War, that they could be had with barrels shorter than 8” and with drift-adjustable rear sights at the breech end of the barrel added to their desirability. This triggered the idea of having a pair of 5,5″ barreled Centaure Marshals converted into LCCs. McDowell further explained these Colt Army Long Cylinder Conversions of yesteryear were assembled from obsolete or rejected percussion parts but were no conversions. Because their cylinders were in fact cartridge cylinders for straight rounds. They were newly lathed and/or converted from old percussion cylinders by turning the rebated segment down to the ratchet stem, adding a ring to build up the area from which the metal was removed, and reboring the chambers through the entire assembly.


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5.7.1_1 Left side close-up original Colt 1860 Army Long Cylinder Conversion: Note 4-screw Cavalry frame


To accommodate these new straight cylinders the water tables of the Colt 1860 frames will have to be milled flat. That is what the old-timers did when they manufactured their LCCs. Their loading levers often stayed in place, too but had no more function. The LCCs usually do not have an integrated ejector. Incidentally, they are not known with an ejector at all.


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5.7.1_2 Right side close-up original Colt 1860 Army Long Cylinder Conversion: NB no loading gate


Historically, the first of these Army LCCs were chambered for .44 Henry RF cartridges. This big bore cartridge was readily available after 1865 in the American West and Southwest. Some were altered to shoot .44 CF fire rounds once such more modern cartridges became available to the public sometime during the middle of the 1870s. Typically their cylinders had no bolt approach notches. Newly lathed specimens were not roll-engraved with a naval cylinder scene.



Next of Kin – Colt 1871/72 Open Top


As the initiates know, these Long Cylinder Conversions (LCCs) share important design characteristics with the later developed Colt 1871/72 Open Top (OT). The OTs were chambered for the same .44 Henry RF cartridge. Quite a few LCCs were fitted with a thin back plate. None had a conversion ring. The Open Top did not have a conversion ring either.


Like the Open Tops (OTs) the LCCs also had a straight cylinder. But theirs’ have the diameter of the large front segment of the Colt 1860 Army percussion cylinder of 4,12 cm/1.622 inch, whereas the OTs cylinder diameter measures less, like between 4,01 – 4,05 cm/1.577 – 1.596 inch.


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5.7.2_1 Original Colt 1971/72 Open Top Late Model with Army grip (picture courtesy Collectors Firearms, Houston, TX, U.S.A.)


Several of the LCCs recorded got a rear sight dove-tailed on the barrel lug, again similar to the OTs sight arrangements but the OTs’ are an integral part of the barrel. Technically, some historians and collectors consider the Long Cylinder Conversions predecessors of the Colt Open Top. In frontier reality more often they were the poor man’s no-nonsense big bore pistol or an economy version of the OT.



Introducing Klaus Mumme – Master Gunsmith, Cowboy Action Shooter and Conversion Artist


For these first Long Cylinder Conversion (LCC) projects German master gunsmith Klaus Mumme of Pirmasens/Germany was trusted with the task of altering a couple of Centaures into LCCs. In addition to being a seasoned smith Klaus is a respected C.A.S. competitor, alias Sliding Horse as well. At the 1st Annual Meeting of the FROCS in July 2010 in Hofheim he applied for FROCS membership which was granted on July 20, 2010. His FROCS is number #77. Mumme’s professional specialty are cowboy guns. He understands what it takes to transform a six-shooter, lever gun or shotgun into a reliable iron for dynamic shooting sports.

I met Klaus the first time in 2004. Back then he altered my Uberti Henry 1860 rifle and an Army san Paolo (ASP) Winchester 1873 carbine from .44-40 to shoot the modern inside lubed .44 Colt cartridge. These jobs were so nicely executed that my pard and fellow FROCS #7 Bumble Bee asked him to give his ASP Winchester carbine the same treatment.


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5.7.3_1 At ease Klaus Mumme and yours truly discussing the LCC project on June 1, 2008


Much more important and closer to the subject here are Mumme’s credentials as the conversion artist of a more recent project: Early in 2008 he altered my 1971 production Uberti fabricated Remington New Model 1863 Army percussion pistol into the below pictured .44 Colt caliber flat backplate arsenal conversion without loading gate.


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5.7.3_2 Mumme-Uberti New Model 1863 Army flat backplate arsenal conversion #24229 in .44 Colt cal.


Conversion artist Bob Millington mentioned elsewhere provided the cylinder for this Remington alteration. Klaus fashioned a new octagon barrel with .429″ rifling groove diameter bore from a .44 Magnum tube, dovetailed the thin recoil plate and historically correct front sight into place. Also, he constructed and fitted the period but still flimsy ejector assembly and modified the percussion hammer with a typical Remington conversion firing pin to ignite my inside lubed .44 Colt cartridges. The finish is traditional blue with a case-colored hammer like the originals. Despite her mileage this Mumme-Uberti Remington New Model Army conversion is one sweet tack driver!



The Making of the Mumme Long Cylinder Conversions (LCCs)