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

5.3 The Making of the Centaure Thuer Conversion

 

5.3 5.3.1 5.3.2 5.3.2.1 5.3.3 5.3.4 5.3.5 5.3.6 5.3.7

The Making of the Centaure Thuer Conversion The Quest for a Modern Thuer The Making of the Nedbal Centaure Thuer Conversion Project Outline Centaure Thuer Conversion Loading Thuer Cases On the Range with the Centaure Thuer Learning by Doing Conclusions More Centaure Thuers?

 

5.3.1

The Quest for a Modern Thuer Conversion

 

Why would one want to have a perfectly functioning Centaure “1960 NEW MODEL ARMY” converted to shoot metal cartridges? What does such a conversion have that a quality Single Action Army or conversion clone of the Italian replica industry out of the box does not offer at a fraction of the price of such a custom-conversion?

But do we conversion-aficionados aka conversionistas want to start another argument about history, passion and desire? You probably heard about this vicious bug by the name Bacillus Conversicus (BC). Many good pards & pardettes got bitten. Once you have contracted BC you can count on regular acute attacks. I got infected early in 2002 when I acquired my first Uberti Colt 1960 Army Richards-Mason conversion in .44 Colt.  I have never recovered.  Actually, I do like these attacks.

The only therapy with a clinically proven effect is targeting, tracking down and liberating another conversion revolver. Alternatively, to have one custom built. The intermittent application of drop-in cylinders, with and without loading gates has been tried by several cowboys and cowgirls with  varying degrees of success. To this day no permanent cure is known!

 

5.3.1_1 Original 19th century Colt 1860 Army Thuer conversion

 

For a couple of years, I have been drooling over these Thuers. Why? Because I wanted a quality repro of a Colt 1860 Army Thuer conversion just because and then some. To bring this statement into some perspective on this Centaure & FROCS website, this was before I got involved with the Centaure research. I even purchased a Uberti made Colt 1860 Army of late 1960 production to mate it with a Uberti Thuer conversion kit when it was advertised back then for launch at the turn of the century:

 

#: This innovative approach on the drawing board from the late 1860s to get rid of surplus stocks of Colt C&B pistol parts from the Civil War and at the same time to avoid royalty payments to Smith & Wesson and Rollin White is just plain stupid elegant.

#: I wanted a modern made, new looking revolver as a shooter without feeling guilty about eventually damaging or destroying a piece of history. This ruled out the real thing.

#: Despite their reputation of functional flaws on the range I enjoy the quality craftsmanship of this never popular conversion system.

#: When Uberti manufactured a few prototype Thuer Armies and conversion kits more than 20 years ago I made up my mind too late and missed the opportunity. Today I know they were never available for sale to the public, anyway.

#: Another chance to own a Thuer Army replica seemed to have unfolded during fall of 2007. At that time my friends from HEGE in Messkirch/Germany presented a series of pictures of their prototype Thuer Army made by a German gunsmith using Uberti parts https://www.waffen-hege.de/de/. It appears this project has been stalled for good.

 

5.3.1_2 HEGE prototype of Colt 1860 Army Thuer conversion made from Uberti parts.

 

5.3.1_3 HEGE Thuer Army accessories and combination loading tool (picture courtesy HEGE, Messkirch)

 

Kudos to HEGE, because their smith even used the proper variant of a Uberti Colt 1860 Army fitted with round 3-screw frame without notches.

 

5.3.2

The Making of the Nedbal Centaure Thuer Conversion

 

During my search for a conversion artist to fabricate my Centaure Richards I learned Karl Nedbal had already been making Thuer Armies from old Ubertis since 1997. Today I know he is fabricating them regularly on special-order – including the loading tool and Thuer cases.

 

5.3.2_1 Nedbal made Uberti Colt 1860 Thuer conversion, C&B cylinder installed, loading combination tool, conversion cylinder, conversion ring, 2 Thuer cartridges

 

More good news regarding newly made Thuers: While this internationally respected and experienced Italian replica manufacturer from Gardone took a management decision against tooling-up for full scale Thuer conversion production around the turn of the century, there exist now a few gifted conversion gunsmiths on both sides of the Atlantic. They are ready to make our dream of custom made, historically correct (and also not so correct; but, shootable) Thuer conversions in both Army and Navy configuration come true.

When a pard from the next village wished to sell his Centaure Regular New Model Army (RNMA) 1st variation 3rd sub-variation #7266 from 1968 I liberated her as project gun for this Centaure Thuer conversion. He had used her during the past 40 years (!) in bulls-eye competition.

 

5.3.2_2 Project gun Centaure RNMA #7266 still in C&B mode right after she got liberated

 

5.3.2.1

Project Outline Centaure Thuer Conversion

 

I had asked Karl Nedbal in March 2008 if he would make a Centaure Thuer for me using this Centaure pistol #7266. When he agreed I left him with this baby for the Thuer project when I collected the Centaure Richards. Incidentally, Nedbal happened to have one of his Uberti Thuers in the shop ready for final fitting and assembly. Hence, the specs of her conversion ring were a mite off and did not work satisfactory with my Centaure (NB: Slightly different specs of Uberti Colt 1860 Army vs. F.A.U.L. 1960 New Model Army).

 

Centaure	Project Outline
Project revolver	RNMA 1st variation 3rd sub-variation #7266
Barrel	8″, Centaure step removed
Barrel marking	„1960 NEW MODEL ARMY“   CENTENNIAL TRADE MARK
Caliber	.44 Thuer, extra cylinder .44 percussion
Rifling groove diameter	.447″ unchanged
Wedge	Centaure
Conversion ring	spring loaded type firing pin
Conversion cylinder	modified extra C&B cylinder #969 factory engraved with Centaure proprietary naval scene
Percussion cylinder	Centaure, custom engraved with Centaure proprietary naval scene
Hammer	modified percussion from Centaure
Grip frame	Centaure brass triggerguard, backstrap with without notch
Finish	traditional (blued/color case hardening)
Accessories	cartridge loading fixture, Thuer cases made from .44 Magnum cases

 

Below are a few pictures that Karl Nedbal shot to document the progress of the making of #7266.

 

5.3.2.1_1 Precision milling the Centaure’s Thuer conversion ring

 

5.3.2.1_2 Thuer conversion ring and cylinder installed

 

This Thuer conversion project developed its own dynamics. Exactly three months after I collected the Centaure Richards Karl Nedbal presented the Thuer to me. August 22,2008 was the day of truth when I took possession of my new toy.

 

5.3.2.1_3 August 22, 2008: Master Nedbal presents three (3) Thuer Army conversions

 

5.3.2.1_4 Three-Thuer-Armies-puzzle: Which one is a 19th century original, which one Centaure RNMA #7266, which one a Uberti?

 

Although Centaure RNMA #7266 saw many years of black powder competition shooting I asked Nedbal not to do a full restoration of the pistol, particularly not to push the worn wedge. But I could not stop him to nicely doming and fire-bluing all screws like you would expect on a NIB original Colt Army Thuer conversion that just left the Hartford factory during the late 1860s. See for yourself.

 

5.3.2.1_5 Nedbal Centaure RNMA Thuer Conversion #7266 cased with Dixon flask, F.A.U.L. nipple wrench, cartridge loading fixture, extra percussion cylinder

 

5.3.2.1_6 Right side close-up of Centaure Thuer #7266: Conversion ring and cylinder installed with Centaure proprietary naval scene engraved

 

5.3.2.1_7 Close-up of conversion cylinder, loading tool with empty cases

 

5.3.2.1_8 Close-up of grip/frame assembly: Conversion ring installed, original arbor, cylinder and barrel pulled

 

5.3.2.1_9 Breech view of cylinders (from left): C&B cylinder before engraving, conversion ring, conversion cylinder

 

5.3.2.1_10 Front view of cylinders (from left): C&B cylinder, bored-through conversion cylinder

 

5.3.2.1_11 Breech view of conversion cylinder, separate conversion ring, note Vienna proof marks and Nedbal maker’s mark on breech side of cylinder

 

For easy loading and ejection of the empties the master recontoured the throat and opened the loading slot. Like the technicians did it at Hartford more than 150 years earlier. He also drilled and threaded the percussion rammer-plunger to receive the Thuer priming punch.

 

5.3.2.1_12 Comparing Centaure percussion (left) to Thuer barrel: Note opened loading slot and threaded plunger

 

5.3.2.1_13 „Clinical“ right side view of Centaure RNMA Thuer #7266

 

5.3.3

Loading Thuer Cases

 

Three big questions need to be answered now: Will the reloading combination tool (aka cartridge loading fixture) work for me like Karl Nedbal demonstrated in his shop? Will I hit what I am aiming at with my Thuer reloads? And finally, will the ejection mode of the conversion ring do its job?

Below pictures were taken during my first reloading session with the Thuer cartridge loading fixtures as the loading tool was called back then in Colt lingo. I use large pistol primers for the cases Nedbal machined from .44 magnum cases. The bullets are heavy soft lead and lubed hollow base conicals of 280 gr.

 

5.3.3_1 Priming Thuer case

 

5.3.3_2 Primed case sitting on loading tool

 

5.3.3_3 Seating the bullet

 

Nedbal gave me a handful of these 280 grainers together with the loading tool. The cases were filled up to the rim with the holy black (Czech Jagdschwarzpulver V, compares to FFg), although the Vienna Proof house approved the Centaure Thuer for smokeless! Once I found my routine of turning the tool forward and backward around the arbor of the Centaure loading these cartridges is a simple, straight forward operation. Now I have an idea how the oldtimers felt sitting on the porch of the bunk house reloading their Thuer empties yesteryear.

 

5.3.3_4 First Thuer cartridge loaded with the 280 grain conical

 

For a detailed description and more pictures of the loading procedure of Thuer cartridges go to chapter 7.5 (English language) or 7.6 (German language), respectively.

 

5.3.4

On the Range with the Centaure Thuer

 

My first time out with the Centaure Thuer was on August 27, 2008 at the indoor shooting range in Hofheim. Loading six (6) cartridges is easy. Only very little force is needed to push them from the front side of the conversion cylinder into the chambers. Firing the first round downrange from 25 meters felt good. Nice boom, pretty thick smoke, easy manageable recoil of the 280 grainers.

 

5.3.4_1 Loading the Thuer cartridges from the front with the loading lever

 

5.3.4_2 Historical moment in Hofheim: First Thuer round fired here ever

 

The next 5 rounds were fired in quick succession using a modified Cooper stance. Quick recovery from recoil was noted. Hits produced satisfactory POA/POI at 8 meters, ejection of the empties with the conversion ring in the ejection mode was positive.

 

5.3.4_3 Thuer recoil of this load? Not worth mentioning

 

5.3.4_4 Positive ejection of the empties after this string

 

It is a joy to shoot this Nedbal Centaure Thuer. She functions reliably most of the time if I do my part. I recommend paying attention to the details, however and don’t get over-excited. Like counting spent shells is always advisable if you do not wish to end up with a Thuer Magnum like I did.

 

5.3.4_5 “Thuer Magnum” fresh round loaded on top of an empty

 

This Centaure Thuer has her personality. This is not what I would call a “forgiving” pistol. I am very happy to have her and look forward to putting her through the paces of more serious target shooting.

 

5.3.4_6 Not bad with 200 grainers at 15 meters: A bit high and to the left

 

She got her next work-out on November 26, 2008 only. Same charge of a full case of black powder. This time I loaded lighter soft lead .45o diameter 200 grain flat base conicals. Since the bullets used were not factory lubricated I used some hand creme with high water content as lube to keep the front of the cylinder and the barrel clean. The Centaure Thuer liked these 200 grainers much better than the heavy 280 grainers of the previous shooting session. Impact was right on target, just 2” to the left of POA and that is OK by me. There were no issues with cylinder locking up from black powder crud or cartridges or empties moving forward during recoil.

 

5.3.4_7 „Clinical“ left side view of Centaure RNMA Thuer #7266

 

5.3.5

Learning by Doing

 

One issue related to the reloading process remained unsolved with these lighter bullets. Seating them straight on the powder is almost impossible with the Thuer loading tool. Therefore, for the next shooting sessions hollow based (HB) and bevel based (BB) .450 diameter 200 grainers were loaded. By now my loading chores were shared by FROCS # 7 Bumble Bee. A few weeks earlier Bumble Bee decided that he could not pass on Nedbal’s Uberti Thuer Army #A14289 in the shop. He liberated her as an addition for his cowboy armament. His deal also included the loading tool.

Using these two (2) types of bullets improved our loading procedures’ routine. The account of properly seated bullets amounted to >9/10 with the HBs and >8/10 with the BBs. Some observations ought to be mentioned here:

# Chamber and case dimensions of these two Nedbal Thuers are the same because the master duplicated the measurements of his original Thuer Army.

# Although the rifling groove diameter of Bumble Bee’s Uberti Thuer is .452″, i. e. bigger than my Centaure’s at .447″ we used the same .450 diameter hollow base and bevel base bullets in both conversions. Accuracy achieved with the two Thuers in terms of bullets’ spread on the target is comparable but different POIs were noted.

# In both Thuers we noted some unpredictable forward movement from recoil of empty cases and even cartridges. Obviously, this affected cocking or firing of the pistols, respectively. In a few instances pulling the barrels of the pistols was necessary to correct the blocked action.

# By use of a chronograph a meager velocity (V2) averaging only 140 m/sec or 460 fps only was noted with these 200 grainers.

 

5.3.5_1 FROCS #7 Bumble Bee shooting the Centaure Thuer: Little recoil, nice smoke and lots of sparks from CZ Jagdschwarzpulver V

 

The analysis of the velocity data led us to test another load. This time hot Swiss CH1 under soft lead .450 diameter 195 grainers of heel type design with flat base was loaded. As a control group the same BP/bullet combination was loaded in the extra percussion cylinders of the Nedbal Centaure and Uberti Thuers, respectively. Here is what we learnt:

# No matter if the Thuer or the percussion cylinder was installed these loads made the pistols kick like the proverbial mule. In the Centaure they felt like an unpleasant .357 Magnum. Felt recoil of the Centaure was a little less than of the Uberti.

• Little smoke, no sparks worth mentioning.
• Centaure average velocity (V2): Thuer 310 m/sec or 1.017 fps, C&B 297 m/sec or 975 fps.
• Uberti average velocity (V2): Thuer 260 m/sec or 853 fps, C&B 249 m/sec or 817 fps.

Four comments, everything else being equal:

1. Slightly lower velocities recorded with bullets fired from the C&B cylinders can be explained by the different type of ignition system used, a closed cartridge system in the Thuers vs. gas leakage – back-firing – through the nipples with the C&B cylinder installed.
2. The slighly lower velocities and less kick (!) of the Uberti can be attributed to her larger bore diameter.
3. Although a crimp is not possible with Thuer cases a positive firm and straight seating into the cases is achievable with flat based heel type bullets easier compared to HB or BB type bullets.
4. The hot CH1 black powder is accountable for the much higher overall velocity compared to the earlier experiments.

 

5.3.6

Conclusions

 

Having studied original and modern made Thuers some, these loading and shooting sessions taught me a lot about this conversion system. These tests provided some insight why the military or real-world cowboys preferred their battle proven C&B Armies and Navies, or the more advanced contemporary Remington cartridge conversions or S&W Americans over Colt pistols of Thuer design. I feel this is an important consideration because it adds to the shooting fun but also brings the significance of these different ignition systems into historical perspective.

# Thuers can be reasonably accurate. In my opinion, they share one inherent flaw, originals and today made ones alike. Provided the latter are turned out as historically correct replications after an original conversion cylinder. Like the originals from the late 1860s the chambers of the Nedbal Centaure conversion cylinder and Nedbal Uberti Thuer conversions have a tapered profile all the way down from the mouth to the breech end!

# During firing the (conical) bullets have no bearing in the cylinder. They are not stabilized by a parallel forward chamber wall. Hence, they hit the forcing cone in an unpredictable upset manner. We found the diameters at the mouth of the chambers greater than the rifling groove diameter of the barrel but oversized bullets represent no solution for the issue here. Bumble Bee’s and my assessments indicate soft lead 195 or 200 grainers with their diameter adjusted to the rifling groove diameter of heel type design represent the optimum in accuracy possibly achievable, followed by hollow based ones as a secondary choice. Bevel based bullets can be considered but flat base ones without heel cannot be recommended.

# The tapered cartridges are loaded from the front into the chambers of Thuer cylinders. They are kept in place by friction only, as are the empties after firing. They might and do move forward from recoil, possibly even when the pistol is carried on a person walking or riding on horseback for a longer period of time. This forward movement might prevent ignition of the cartridge, it can make re-cocking and firing a Thuer difficult, even impossible, when the going gets tough. This aspect might explain why big bore Thuer revolvers never caught-up to become a preferred fighting handguns of the Americans back during the days.

 

5.3.7

More Centaure Thuers?

 

We know of one Centaure Civilian 1st variation #C215 altered into what only looks like a Thuer conversion. U.S. gunsmith and CAS competitor Gary Barnes aka FROCS #204 Hoof Hearted from Tolar, TX, completed this task for a client around 2013/14 http://cartridgeconversion.com/. This Civilian was fitted with his patented NEW IMPROVED Thuer® Conversion in .45 Schofield cal. holding five rounds.

 

5.3.7_1 Centaure Civilian 1st variation Thuer #C215 converted to breechloading .45 Schofield cal.: Resting on C&B cylinder, Thuer cylinder installed

 

This conversion drop-in cylinder looks like a Thuer cylinder from yesteryear. But in reallity it is a breech loading system even though to load and unload the barrel has to be pulled. This is what sets it apart from the 19th century originally or newly made Thuer conversions put together in the historical manner. Interestingly, the ejector parts of the conversion ring found in the originals have been omitted. Gary Barnes modified the function allowing a safe spot to rest the hammer for dry firing. With the original percussion cylinder installed the revolver works as a C&B pistol.

 

5.3.7_2 Close-up of barrel lug/conversion cylinder/frame assembly of Centaure Civilian Thuer #C215

 

Updated February 6, 2024

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