Centaure Long Cylinder Conversion

# What is a Colt Long Cylinder Conversion?

# Next of Kin – Colt Open Top M 1871-72

# The Making of the Centaure LCCs

# Proof Testing & the BATF

# The Day of Truth

# Range Report 1

# Range Report 2

# Growing Pains

# Ready for Action – at Last


What is a Colt Long Cylinder Conversion (LCC)? Bob Millington’s (www.armsportllc.com) 3rd generation Colt 1860 Army Long Cylinder conversions in Dennis Adler’s book COLT SINGLE ACTION FROM PATERSONS TO PEACEMAKERS should have received more attention. Because this rustic and economical approach to convert mostly 1860 Armies but also a few 1861 Navies to cartridge firing pistols 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. Because this triggered the idea of having a pair of short barreled Centaure Marshals converted into Long Cylinder Conversions. McDowell further explained that the Colt Army Long Cylinder Conversions of yesteryear were no conversions but assembled from obsolete or rejected percussion parts but their cylinders were straight round cartridge cylinders. They were newly lathed or converted from a old C&B cylinder by turning the rear section 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.

Originally these Army LCCs were chambered for the .44 Henry RF but some were altered to shoot .44 center

fire rounds once such modern cartridges became available. Typically their cylinders had no bolt approach notches. The newly lathed specimens had no naval scene roll-engraved.

#12089 (left) and #12067 (right) – base pistols for Long Cylinder Conversions

Pictured above are my Marshals #12089 and #12067. They are the candidates for the conversions. #12067 was selected because she needs “waynerizing” anyhow. In addition to this waynerizing this conversion project shall accomplish another objective: I need a new pair of stylish match pistols. It will be cool to use a pair of Centaure Marshal LCCs in Cowboy shoots instead of my Uberti Open Tops.

Next of Kin – Colt Open Top M 1871-72: Incidentally, the LCCs featured many design characteristics which are to be found on the later developed Colt Open Tops as well. They were chambered for the same .44 Henry RF/Stetson .44 Henry RF cartridge. Some LCCs were fitted with a thin back plate but none had a conversion ring. The Open Top did not have a conversion ring either. Like the OTs the LCCs also had a straight cylinder. But theirs’ have the diameter of the large front section of the C&B cylinder, whereas the OTs cylinder diameter is that of the smaller rear section.

As already mentioned above quite a few LCCs got a rear sight dove tailed on the barrel lug, again similar to the OTs sight arrangement which is an integral part of the barrel, however.

To accommodate the new straight cylinders the steps in the Marshal frames will have to be milled flat. That’s what the oldtimers did when they manufactured their LCCs. Like the originals their loading levers will stay in place but have no more function. The LCCs do not have an integrated ejector. Actually, they don’t have an ejector at all. In a nutshell, therefore, you can call the Long Cylinder Conversions the poor man’s or economy version of the Colt Open Top.

Original Colt M 1871-72 Open Top

Close-up of Mumme Uberti Remington Army conversion #24229

The Making of the Centaure Long Cylinder Conversions: This time German toolmaker and master gunsmith Klaus Mumme of Königsbronn was trusted with the conversions. Klaus is a respected CAS competitor. His alias is Sliding Horse. At the July 2010 Centaure convention in Hofheim he applied for the FROCS membership which was granted July 20, 2010. He is now FROCS #77.

Mumme has many years of solid gunsmith experience with cowboy guns in general. He understands what it takes to make a reliably functioning cartridge firing pistol. I first met him 2004. Back then he altered my Uberti Henry 1860 rifle and an ASP Winchester 1873 carbine from.44-40 to.44 Colt caliber. 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.

However, more important and closer to the subject here are Mumme’s credentials as converter from a more recent project: in early 2008 he altered my Uberti Remington Army C&B pistol of 1971 production into the .44 Colt caliber “factory conversion” without loading gate pictured above.

Centaure Long Cylinder Conversion

Project Outline

Base pistols

Marshals 1st variation, 2nd sub-variation #12067 & #12089



Barrel marking



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

Ejector housing




Conversion cylinder

newly lathed, without rabate, engraved Texas cattle brands


altered Centaure, nose bobbed with firing pin

Hammer stop

screwed in front of recoil shield with guiding hole for new hammer nose

Rear sight

dovetailed and mounted on barrel, blued


step has been milled off

Recoil shield

cartridge loading channel cut into right recoil shield


Centaure (steel, with cut for stock)


Centaure (brass)


blued incl. frame, hammer in the white

The cylinder for this Remington conversion was provided by the afore mentioned Bob Millington. Klaus fashioned a new octagon barrel with .429 dia bore, dovetailed the thin recoil plate and PC front sight into place, constructed and fitted the period correct ejector assembly, and modified the C&B hammer with a PC firing pin to ignite the CF .44 Colt cartridges. The finish is blue with a traditional case colored hammer. Despite her mileage this Mumme Uberti Remington New Model Army conversion is one sweet tack driver!

Klaus Mumme and yours truly discussing at ease the LCC project June 1, 2008

After a lot of discussions backwards and forward during the following months regarding technical details of the conversion project and finish it was finally agreed that these 2 Centaure cartridge conversions will be completely rust blued, no case colors whatsoever! Initially, my preference was nickel plating like many of the originals but this thought was dismissed. From the Centaure RM I learnt the hard way how difficult alignment of shiny sights in bright sun light can be.

LEAD Technologies Inc. V1.01

Step of frame removed, back-plate before contouring

LEAD Technologies Inc. V1.01

To be turned into 2 LCC cylinders …

LEAD Technologies Inc. V1.01

in the white

The newly made conversion cylinders of the LCCs are lathed from 1.7225-42 CrMo4-V320 steel. That is the same alloy Karl Nedbal uses for his conversion cylinders in the Richards, Richards-Mason, “Mystery” and Richards Transitional projects. The LCC cylinders will be engraved with Texas cattle brands.

Proof Testing & the BATF: When the conversions were finally completed sans rear sight, engraving and bluing in January 2010 they were presented to the Munich Proof house for proof testing. There was an unexpected hold-up. The proof house slammed on the brakes. They felt not comfortably applying their stamp of approval for “design deficiencies”.

No loading gate needed: cartridges and empties are kept in place by the recoil shield…unless you cock the pistol aiming at the sun

Texas cattle brands engraved on conversion cylinder. Note bobbed hammer with firing pin

No, they were not worrying about the open top design. They smelled potential danger from a conversion without loading gate, preventing cartridges or empties from dropping out of the pistol during firing or blocking the action. They stuck to this position despite the fact that they had proof tested my above Remington “factory conversion” 2 years ago which does not have a loading gate either!

They only changed their minds May 12, 2010 (!) when the historical correctness of this type of conversion was presented through supportive printed evidence from Dennis Adler’s and Bruce McDowell’s books. No more discussion and the proof marks were finally applied.

Thanks, Klaus for your patience dealing with these worry warts.

August 7, 2010: #12089 almost completed

Another important accomplishment was recorded with this project June 16, 2010: the BATF Bureau of Alcohol, Tobacco, Firearms and Explosives of Martinsburg, WV, confirmed that custom converted FAUL Long Cylinder Conversions in .44 Colt can be legally imported into the USA on a temporary base! One could also say an important US government agency recognized this project.

Only August 7, 2010 I could take the first look at almost completed LCC #12089. Just a few finishing jobs are needed like cutting the dovetail on the breech end of the barrel to install the rear sight, test firing her and adjusting the sights to bring POA and POI together, and finally polishing and rust bluing the Centaures.

Stay with me when we are approaching the finishing line of this project!

The Day of Truth: December 5, 2010 after some 30 months the deed is done, the conversion of my new pair of CAS match pistols is completed. They were personally delivered by Mumme to my house. During the bluing process he noted that an even blue-black color of the originally high gloss polished steel of the Marshals could not be achieved. Not even after a second and third attempt. Now they have this antique like mottled look. I like it.

#12089 appropriately resting on Dennis Adler’sbook COLT SINGLE ACTION FROM PATERSON TO PEACEMAKERS: note dovetailed rear sight

During his test firing Mumme could establish that both pistols were shooting to POA at a typical CAS distance of 10 yards with very little spread. No tools were needed to drop the empties out of the cylinders.

Now the $ 10,000.00 question: is this Mumme Centaure LCC the ultimate CAS pistol for a cowboy portraying an early 1870 character? You bet and lots of style points are on the horizon! As a side note our FROCS & buddy Bumble Bee was pretty impressed by Klaus’s conversion jobs. He happened to be at my house with two of his Centaures when Mumme delivered my new toys. BB was so hot that he through his RNMA 1st variation #11681 on the table to have her converted to … you guessed it … an 8” barrelled LCC! He plans to use her together with his 7,5” barrel Uberti OT as his main match pistol! According to Mumme this time the conversion will only require 3 months. He explained that by the experience gathered converting my Marshals, ha!

Sights of #12089

No loading gate. Note hole in hammer stop/back-plate for firing pin!

Range Report 1: First work-out of my 2 Marshal LCCs took place December 8, 2010. Accuracy at CAS distances is OK by me but I need to get used to their short sight radius before I test them at longer distances like 25 and 50 meters. The objective will be to establish their accuracy potential but more importantly their long term reliable function.

Some cocking issues were noted with a two handed hold due to the lack of a loading gate. When the pistols were slightly raised while being cocked some cartridges or empties would move a bit backwards into the loading channel and block the action. The answer to this? I have to learn shooting them duellist style.

First shooting impressions at 10 meters/11 yards: pistols cocked & fired as quickly as possible, aiming at the bulls eye…

…#12067 connecting slightly to the left and #12089 slightly to the right. Correction is easy with the drift adjustable rear sights.

Range Report 2: Gave my Marshals another workout March 9, 2011, with some CAS holster & shooting drills. The objective was to get a feeling of their reliability under CAS conditions, how smooth the action felt after Klaus Mumme gave them some fine tuning and also an evaluation POA vs. POI shooting duellist style.

For the records: after I switched to duellist style shooting I had no more cocking issues.

They were loaded with my light standard CAS load of 200 grainers over smokeless powder.

Close-up of #12089: note hole for firing pin in back plate. Back plate is epoxied and fixed to recoil shield with 2 screws

# reliability was satisfactory initially but after 30 rounds fired through both of them the barrel stud of #12089 went flying. Function of the pistol was not affected by this incident because the lever screw was fixed very tight. Found the stud in the dust of the range later and fixed it to the barrel with epoxy.

# pointability of both pistols is excellent as you would expect from the Army lineage. You hit what the front sight is pointing at. They lean themselves to point-shooting which is against BDS & CAS rules, however.

Centaure cylinder evolution (left to right): C&B, Thuer, LCC, Richards

# unloading empties: I was amazed again how easy empties can be removed although these LCCs don’t have an ejector. Just bring the hammer in the half-cock position, point the barrel upwards, turn the cylinder and the empties will drop out. Period, just like this. Getting the empties out after a couple of stages have been shot might become a different story, however, when the chambers are dirty from powder residue.

Breech view of the cylinders (left to right): C&B, Thuer, LCC, Richards

# mainspring & slicking up the action: both pistols were fitted with Uberti SAA mainsprings instead of the hard original Centaure ones which are recommended for C&B pistols. Cocking of #12067 was a bit harder compared to #12089 but not unpleasant. Her mainspring may need some more lightening. Incidentally #12067 was the pistol that needed waynerizing when still in C&B stage. Some amateur had worked the bolt and the hand. After some additional attention she got from Klaus her action is still a bit stiff compared to #12089. This should improve over time with some more mileage. For the time being I can live with it.

# triggers of both pistols are just ... sweet. Broke like glass!

Mexican twins: mottled look of #12089 (top), #12067 (bottom)

I feel that this Long Cylinder Conversion concept has potential in CAS for main match pistols, particularly if duellist or double duellist is your preferred class. That was the comment of European champion in the classic cowboy class Michael "Lederstrumpf" Mayer after he fired a couple of strings through both pistols yesterday as well.

Growing Pains: But all Spring and most of Summer went by before the pair was really ready for serious cowboy action. Here is a list of minor and major headaches that needed to be addressed.

# barrel studs: the epoxy did not do its job on the barrel stud of #12089. It went flying again during my 3rd string of 5 rounds a week later. To make things worse so did the stud of #12067. Obviously medicine stronger than epoxy was required to cure this ailment. Welding the studs with a dental laboratory laser seemed to be the way to go. This worked and still works perfectly until today for #12089 but not for #12069.

During the next work-out session her stud went off flying again. Another session with the laser was called for but again this fix did not do the job. After consulting with the smith the only option left seemed to manufacture a new stud with a wider base and to cut a new, wider and deeper dovetail into the barrel. And that did it, finally. We are now well into June.

# action job of #12067: while #12089 works flawless after her one laser welding, cocking of #12069 became more and more difficult during all this experimenting with the fixes of her barrel stud. It reached a point were cocking under match conditions was almost impossible. It seemed that both hand and bolt were not properly hardened and also the hammer cam had suffered some. Possibly the timing was gone. Time for a full overhaul of the action including fitting a newly fabricated bolt and hand. This was accomplished by mid August.

During the latter part of August and early September both pistols were given the .44 Colt treatment with some 200 rounds each of my regular light CAS load. Both pistols performed fine, no flying studs, no timing issues. So, I was confident that shooting them at the forthcoming FROCS meeting September 10 would be just a piece of cake.

# new front sight: during main match and the side matches at the FROCS meeting both C&B and conversion Centaures were to be fed with BP loads only. And that was a stiff gentleman’s load of CH2. #12089 went flying through the paces but #12067 again had issues. No action or stud troubles this time but the front sight went off during the second stage of the main match. This was frustrating some because I could no longer compete but apart from that was no immediate disaster … but it could quickly develop into a major PITA … because I had registered both pistols for temporary import into the USA with the BATF for the War Dept’s and my Texas vacation 10 days later. But again luck was on my side.

Ready for Action – at Last: Gunsmith and LCC converter Klaus Mumme aka FROCS #77 had attended the FROCS meeting, that is the good news. He took ailing #12067 back home to his shop in Southern Germany for the making and installation of a new front sight of proper height … which he did at no charge. So, #12067 was back in Hofheim a week later and I was ready for some shooting action Texas style!

Thanks to this timely support of Klaus I could attend the Sunday shoot of the Tejas Pistoleros at Eagle Lake September 25 and the Annual Shoot of the Canadian River Regulators at the Bar H Ranch in Clarendon October 8, 2011 with both Centaure Long Cylinder Conversions in perfect shooting order. Even did quite well at the bullet splitting contest. It was about time …

Colt Army conversions with Mexico Connection? From Vösendorf/Austria Nedbal “Mystery” Conversion (top), Königsbronn/Germany Mumme Long Cylinder conversion (bottom)


WDN/October 26, 2011

© 2007 Wolf D. Niederastroth