Gun Smithing the Centaure

Under construction.

“If the Belgian is together right it shoots real good” (respectfully quoted from Rifle the Centaure Doc).

Spare Parts & Gunsmiths: many of those Belgian Colt Armies offered these days at auctions or gun shows have signs of many years of (ab)use in BP shooting. Often parts are worn and/or need to be replaced. Since production of these pistols was terminated 1973 original spare parts are rare and would be a lucky find. Therefore, sharing such information regarding sources for parts but also gunsmiths who are experienced enough to make such parts or repair our Centennial Armies is needed.

On many occasions, however, commercially available parts of Italian 1860 Army clones can be used with little fitting.

Waffenhaus am Bodensee GmbH

Schanz Strasse 13

D-88045 Friedrichshafen


Phone +49-7541-3771-66

Fax +49-7541-3771-67

have some inventories of selected original Centaure spare parts like bolt stops. Check back with Werner H. Withum there.

Consulting with gunsmiths very knowledgeable with the repair, making or replacement of parts of the Belgians is always a good idea. Below are a couple of suggestions from expert gunsmiths and Centaure tinkerers from all around the globe. Most of these tricks of the trade, however, are from this US expert C&B “hobbyist” gunsmith pictured above left who happens to be an avid hunter, too. He goes by the alias of Rifle. Therefore, if you have an issue with your Centaure and happen to be on the Western side of the big pond then Rifle can supply some “advice”. Reach him by email at

# Barrels: Barrels of Uberti Colt 1860 Army repro can be used for replacements to Centaures but … a new arbor may have to be fitted or some welds may need to be strategically placed on top of the original arbor to tighten the fit of a replacement barrel to the smaller diameter Centaure arbor.

The alignment of the bore of the barrel to the chambers is a thing to check to properly fit a replacement barrel to a Centaure.

Please, note that the Centaure barrel groove diameter is .445/.446 in. It is adjusted to the chamber diameter for maximum accuracy, whereas the Uberti barrel groove dimeter is usually ca. .451 in.

# Bolt: Competent gunsmiths make replacement bolts from scratch, or use bolts from Pietta and make them work nicely in a Centaure.

# Bolt/Trigger Spring: Uberti springs for SAAs, Armies, Navies or OTs will usually work. Aftermarket piano wire springs might be the better choice if you wish to use your Centaure in CAS activies.

#8105 with fluted Italian replacement cylinder Replacement cylinder for #8105 marked 76 on breechside

# Cylinder: If a functional replacement is needed Uberti cylinders will work with some fitting but have a chamber diameter that will be at least .005 inch bigger than the groove diameter of the Centaure barrel. Since the pistols fire round balls that have a short bearing surface in contact with the barrel interior that can be done.

Pietta cylinder is the right chamber diameter being only about .001 inch bigger than the barrel groove diameter and can be modified to fit a Centaure. The ratchets at the rear have to be reduced in diameter to fit the Centaure.

# Grips: To remove the protective shellac from the grip applied at the Belgian factory but also to clean old worn grips a good wipe with some steel wool soaked with ethyl alcohol works for me.

Once the wood has dried I give it a further treatment with dry steel wool before an application of Schaftol or linseed oil as a protection and to enhance the grain structure. Repeat application as needed, use steel wool between applications until the surface has the desired level of smoothness and silkiness.

Regarding my pair of CAS main match Centaures I have their fat area at the bottom of the grip panels flattened by ca. 2 mm on each side. For me this provides for a more positive grip during the draw, faster target acquisition, and there is no sideways twist to talk about during recoil.

# Hammer: A Pietta hammer can be fixed to work in a Centaure.

# Hand: A Pietta hand can be used with some tinkering.

# Mainspring: The original factory mainsprings are of the heavy duty, stiff kind. They were installed at the Belgian factory for good reasons:

  • Positive ignition of the caps even under adverse conditions
  • Not letting the hammer moving backwards some when the gases came back through the nipples, to prevent
  • Chain-fires from badly fitting caps, but more important
  • Misalignment of chamber and barrel if the bolt leg is close to the hammer cam the cylinder can be moved by the hand upon firing. That would set the chamber alignment off too much before the ball is out and make the pistol shoot … ”suboptimal” with hits spread all over the target.

Uberti mainsprings will usually work without fitting. However, theirs is weaker than the original. That’s why the expert gunsmiths rather “reanimate” a dead original spring, or work down a heavy duty Dragoon spring and make it fit to the Centaure.

Please, consider these experiences of US master gunsmith Rifle: “Revitalize” a weak or over-bent original spring back to proper shape and function?”

“You can bend it if you soften it by heating it red and letting it air cool slow. Then after it’s bent heat it red and throw it in water then polish it off some and heat it till it turns blue and let it air cool.”

“If that doesn’t work on the type of spring steel then maybe you can file to size a Dragoon spring to fit the Belgian unless it’s as short as an Uberti 1860 spring then use the Uberti.”

# Nipples: Before you can replace worn or burned out nipples you have to get them out of the cylinder pocket which often is an issue. This wooden board with the 2 hardwood pins might be a useful little helper in this process.

However, even with the best nipple wrench you are at a loss when the nipples are nicely baked into the threads because this previous owner of your Centaure never cleaned that pistol properly. And penetrating oil, application of heat and/or cold gets you only so far when the nipples are really stubborn and uncooperative.

Here is what Rifle is suggesting in such a situation:

“It’s the downward pressure that’s the trick.”

“Use the drill press to get out stuck nipples. The drill press is not turned on. The drill press is used only to exert downward pressure on the nipple wrench so it doesn’t slip off the nipple.”

“The spindle or chuck with the nipple wrench in it is turned by hand to loosen the nipple.”

Doing it Rifle’s way … … 4 stubborn nipples stuck in #4612 … tough job for FROCS #18 Lucasia
3 nipples have surrendered, one to go The deed is done! Great job, thanks Lucasia

Not all of us cowboys & cowgirls are lucky, own or have access to sophisticated machinery in our gunsmith shop like Lucasia or Rifle. Or they are not comfortable using such hightech equipment like me. Often it will be necessary to do the job using available rudimental tools only. Here is what works well for me.

I start with a caveat, however: This method works but be aware that the fix of the wrench on the nipple will be a fragile one!

Step 1: Fix the board to your bench Tools recommended (left picture) are #1 the afore mentioned board with the 2 hardwood pins, #2 a solid C-clamp (vise), #3 a perfect fitting, ideally flat headed quality nipple wrench (round head will work, too but you have to be more careful that it is not slipping off from under the vise), #4 just in case a tube of some kind that can be slipped over the handle of the nipple wrench as an extension of the lever, to apply more torque if needed.

Here we go:

Step 2: Position your cylinder on the guiding pins of the board, breech side up

Step 3: Place your nipple wrench on the frozen nipple Step 4: Solidly fix the wrench with the C-clamp

Particular care must be taken that the wrench is in a straight upward 90° position all the time!

Adjust counter-pressure of C-clamp as the nipple is coming loose. As per Rifle’s recommendations the C-clamp is only needed to exert the downward pressure on the nipple wrench.

Once the old nipple is out commercially available nipples from Pietta are of the same thread size as the Centaures, namely 6 mm-.75. Use lathe to turn shoulder of cones to match the nipple rebate in cylinder. Cone threads are longer, may need to use tap of same 6 mm-.75 threads to extend threads in cylinder, or shorten the threads of the nipple if it is possible without enlarging the ignition hole in the nipple. Shorten top of cones to match Centaure’s lengths for caps.

Step 5: Turn lever of wrench slowly and carefully to loosen the frozen nipple, a tenth of a mm or inch at the time. Use extension on handle of wrench as needed. Alternatively you may want to consider installing newly fabricated beryllium nipples made for Centaures.

They are available from


Jürgen Achenbach

Bombergstrasse 21

D-35713 Eschenburg


Phone +49-2774-72122

Fax +49-2774-918810

Jürgen Achenbach is the man to talk to at Vorderlader-Shop.

# Removal of frozen screws: Use same technique that worked to loosen the nipples! Instead of the nipple wrench fix a bit of the right size and a proper fitting spanner as lever. The removal of the uncooperative screw will probably require some fixing and stabilizing to secure the 90° upright position of the bit!

# Trigger: Can be made from a Pietta – for cases where a long one is needed – or Uberti trigger – although longer than the Centaure trigger, can be used if the long length is not needed – with some fitting and contouring.

# Wedge: Take the measurements of the hole for the wedge in barrel lug and arbor. With these measurements

in mind get a replacement wedge from Uberti – best fit: a hair narrower at the rear, works good -, or Pietta – fit would work but rear narrower than Uberti.

~ASM – went through too easy – and ASP/Euroarms – went right through – cannot be recommended.

Re-contouring an oversized wedge to proper size might be easier than fixing shim to an undersize wedge.

The front of the arbor’s slot can be welded and re-filed to make a slot narrower so that a narrower than original wedge available from the factory made replacement or another manufacturer can be used and providing available replacements in the future.

This list will be amended as additional gunsmithing trade tricks become available. You may also want to check the Centaure Forum since further information might have been posted there.

WDN/March 5, 2013

© 2007 Wolf D. Niederastroth