Question: About Double rifle

[Gert Odendaal]

Are both barrels right hand rifling ?
Is one barrel right hand rifling and the other barrel left hand rifling?
Are double barrel rifle`s profiles determined by caliber?
Is there a spesific taper ratio from the chamber down to the muzzle of the double rifle?

 

[A.M. Little]

Commonly both barrels are right hand rifling. At times there have been some marketing attempts at different twist directions being of theoretical benefit. I have no experience with such because “if it isn’t broken”.

As for barrel profile it’s a can of worms with a lot of variables that will depend on the overall conceptual desires of the maker regarding weight, balance, handling, and any budget concerns.

I prefer and will be offering guns that carry the majority of the weight between the hands, which leads me to preferring a larger action body to get up to desired weight, with barrels that taper quickly. Typically my barrel profiles result is a wall thickness of .100” at the mid point, which carries out to the muzzle. Sometimes I’ll even get down to .085”-.090” wall thickness at the muzzle. This concept does not allow for the ability to share action sizes between calibers, as it is built without compromise.

When budget constraints demand you will start to see action sizes shared between calibers; say .450ne, .470ne, and .500ne. While sharing sizes Say between 450 and 470 or 470 and 500 isn’t terribly problematic to work around, the jump from 450 to 500 is too much. Often you will see manufacturers leave more meat in the barrels on the larger .470ne and .500ne’s to attempt to get to a higher desired weight. This leads to a gun that is too forward biased in my opinion, sometimes weight is added in the stock to help bring balance back and gain overall weight. You also often see no attempt at increasing barrel weight on such, and then you’re left with a 9.5-10lb .500ne.

 

[AZDAVE]

Both barrels are right hand rifled.

No sure one your two last questions.

 

[Gert Odendaal]

Commonly both barrels are right hand rifling. At times there have been some marketing attempts at different twist directions being of theoretical benefit. I have no experience with such because “if it isn’t broken”.

As for barrel profile it’s a can of worms with a lot of variables that will depend on the overall conceptual desires of the maker regarding weight, balance, handling, and any budget concerns.

I prefer and will be offering guns that carry the majority of the weight between the hands, which leads me to preferring a larger action body to get up to desired weight, with barrels that taper quickly. Typically my barrel profiles result is a wall thickness of .100” at the mid point, which carries out to the muzzle. Sometimes I’ll even get down to .085”-.090” wall thickness at the muzzle. This concept does not allow for the ability to share action sizes between calibers, as it is built without compromise.

When budget constraints demand you will start to see action sizes shared between calibers; say .450ne, .470ne, and .500ne. While sharing sizes Say between 450 and 470 or 470 and 500 isn’t terribly problematic to work around, the jump from 450 to 500 is too much. Often you will see manufacturers leave more meat in the barrels on the larger .470ne and .500ne’s to attempt to get to a higher desired weight. This leads to a gun that is too forward biased in my opinion, sometimes weight is added in the stock to help bring balance back and gain overall weight. You also often see no attempt at increasing barrel weight on such, and then you’re left with a 9.5-10lb .500ne.

Thank you kindly Aaron , your reply is much appreciated.

Aaron , yes it makes sense to have the weight between the hands , it surely will make for a great handling double rifle.

Since financially it really is challenging to purchase a Double rifle in a country where our currency is so weak it is necessitated to think out of the box ...although it has been done many times previously : Building a Double Rifle on a SxS shot gun action.

I am planning such a build when the 500 Jeffery build is completed , researching this concept. I decided on a 45-70 Government caliber . The re-loading components are available and affordable . It will be a fun shoot rifle . I need to know what taper/specification of the barrels are required since I will order from a barrel manufacturing company here in South Africa.

The action will be a 16 ga SxS with a Greener type cross bolt , the pressure will be CIP , black powder rifle specs...although I am sure 30000PSI is safe .

At least the last 300mm of the barrels I want the manufacturer to thin out to ensure """weight between the hands effect"""

 

[Gert Odendaal]

Both barrels are right hand rifled.

No sure one your two last questions.

Good day to you Dave, it is good to hear from you again. Thank you for the reply, it is much appreciated.

 

[A.M. Little]

Actually, I have two guns in the shop now that show perfectly the contrast between compromise and none. A pre-war .475 Jeffrey and a modern Chapuis .470ne. For arguments sake the guns should have the same overall weight.

WJ Jeffrey
2.310” breach width
24” barrels weighing 6lbs 7oz
Barrels balance 8.5” in front of breach


Chapuis .470ne
2.065” breach width
24” barrels weighing 5lbs 15oz
Barrels balance 9.5” in front of breach

So despite the J barrels being heavier they balance closer to the breach, combined with the larger action body it brings the weight well centered and of higher weight than the C. Despite this higher weight the handling and balance is sublime, and you wouldn’t know pointing it that this was the case!

 

[A.M. Little]

Thank you kindly Aaron , your reply is much appreciated.

Aaron , yes it makes sense to have the weight between the hands , it surely will make for a great handling double rifle.

Since financially it really is challenging to purchase a Double rifle in a country where our currency is so weak it is necessitated to think out of the box ...although it has been done many times previously : Building a Double Rifle on a SxS shot gun action.

I am planning such a build when the 500 Jeffery build is completed , researching this concept. I decided on a 45-70 Government caliber . The re-loading components are available and affordable . It will be a fun shoot rifle . I need to know what taper/specification of the barrels are required since I will order from a barrel manufacturing company here in South Africa.

The action will be a 16 ga SxS with a Greener type cross bolt , the pressure will be CIP , black powder rifle specs...although I am sure 30000PSI is safe .

At least the last 300mm of the barrels I want the manufacturer to thin out to ensure """weight between the hands effect"""

.45-70 is a wise choice on a 16ga frame. Try to get as close to .660-.675” OD at 12-14” from the breach and carry that out to the muzzle. I assume you have a barrel OD of around .900”-.930 where you intend to place the monoblock seam?

Try to find a donor with bushed firing pins. Make new bushings with FP holes around .065”-.070”, and turn the firing pin tips to match closely.

 

[Gert Odendaal]

.45-70 is a wise choice on a 16ga frame. Try to get as close to .660-.675” OD at 12-14” from the breach and carry that out to the muzzle. I assume you have a barrel OD of around .900”-.930 where you intend to place the monoblock seam?

Try to find a donor with bushed firing pins. Make new bushings with FP holes around .065”-.070”, and turn the firing pin tips to match closely.

Excellent, I will send this information to the manufacturer Eagle Barrels ..Frans Odendaal is really making high quality barrels ..

 

[Gert Odendaal]

If ever I could afford a double rifle the .475 Jeffery will be my ultimate choice ,,
WJ Jeffrey
2.310” breach width
24” barrels weighing 6lbs 7oz
Barrels balance 8.5” in front of breach

 

[Gert Odendaal]

.45-70 is a wise choice on a 16ga frame. Try to get as close to .660-.675” OD at 12-14” from the breach and carry that out to the muzzle. I assume you have a barrel OD of around .900”-.930 where you intend to place the monoblock seam?

Try to find a donor with bushed firing pins. Make new bushings with FP holes around .065”-.070”, and turn the firing pin tips to match closely.

Excellent, yes I have read about thinning out the barrels 300mm from the muzzle back to the breach...this will give you the balance between the hands...

I have two choices ..cutting the 16 ga barrels and thread/solder the 458 barrels into the the stubs.

Second choice : mill out a new complete mono-block and fit it to the action ....

Question: I then have to look for another donor with bushed firing pins , a Greener type cross bold as well...I was searching for a Simson Suhl SxS donor action, unfortunately there is not such a shot gun available that I know off ..Classic Arms informed me they might get a Simson Suhl SxS in the future..I still want to search the large Rifle/Gunsmith shops in the other provinces ..

Your advice is much appreciated Aaron.

 

[A.M. Little]

Often the German guns have smaller than standard firing pin diameters on their shotguns. If you can find one with firing pin tip diameter around .070”, and it fits it corresponding hole well you’ll be fine.

The issue arises when you have larger firing pin diameters that fit the holes poorly which can lead to primers flowing into said holes, making the gun hard to open, or even possibly rupturing and venting gasses into the action and blowing out the stock head.


The BRNO ZP guns come in 12ga and 16ga, either would be fine for a .45-70. You could also step up to a 450/400 on the 12ga if desired. The majority of the ZP guns will have bushed firing pins, but not all. The ZP guns have a hidden Purdey 3rd bite instead of a greener crossbolt. Perfectly fine, and I’d propose the firing pin situation is of more importance.

 

[Tintin]

Gert,

You're probably aware of this book

Building Double Rifles on Shotgun Actions
by W. Ellis Brown

Books - Bunduki Publishing

Building Double Rifles on Shotgun Actions – Third Edition by W. Ellis Brown This book is written to take the gunsmith or advanced hobbyist step by step through the process of building a double rifle, using the action of a side-by-side shotgun. Chapters include evaluating actions and cartridges...

bundukipublishing.com

Mark

 

[Gert Odendaal]

Often the German guns have smaller than standard firing pin diameters on their shotguns. If you can find one with firing pin tip diameter around .070”, and it fits it corresponding hole well you’ll be fine.

The issue arises when you have larger firing pin diameters that fit the holes poorly which can lead to primers flowing into said holes, making the gun hard to open, or even possibly rupturing and venting gasses into the action and blowing out the stock head.


The BRNO ZP guns come in 12ga and 16ga, either would be fine for a .45-70. You could also step up to a 450/400 on the 12ga if desired. The majority of the ZP guns will have bushed firing pins, but not all. The ZP guns have a hidden Purdey 3rd bite instead of a greener crossbolt. Perfectly fine, and I’d propose the firing pin situation is of more importance.

Your advice and information you are sharing with me is much, much appreciated for sure. I looked at the ZP 49 749 model I think..it is the top of the range in the CZ "Special Poldi " version as the exhibition grade SxS in 12ga ..I really would prefer a 16ga version..
I already have a 404 Jeffery so the 450/400 caliber in a double would be a duplicate ...I really want to build a rifle in the 45-70 Government version..

A description of the CZ SxS 12 GA Model 749:
ZP 749: Represents the pinnacle seventh tier of finish for the 12-gauge auto-ejector platform. These are top-tier, custom-shop Exhibition Grade models featuring premium high-grade checkered walnut stocks, hand-engraved full scroll actions, cocking indicators, and intercepting sears

 

[Gert Odendaal]

Gert,

You're probably aware of this book

Building Double Rifles on Shotgun Actions
by W. Ellis Brown

Books - Bunduki Publishing

Building Double Rifles on Shotgun Actions – Third Edition by W. Ellis Brown This book is written to take the gunsmith or advanced hobbyist step by step through the process of building a double rifle, using the action of a side-by-side shotgun. Chapters include evaluating actions and cartridges...

bundukipublishing.com

Mark

Mark, good to hear from you..I already bought this book 12 years ago..this is how long I am already planning this project...It is a good guide for me , I also followed Ron Vella who build a lot of double rifles in various calibers..Ron tend to use the CZ SxS shot guns as donor actions...

I bought a 12GA Zabala SxS shotgun at a give away price as well..I just want to see if the action is still tight and the table is in good condition..then I have to look at the safety features of the ZABALA 12ga shot gun to see if it is strong enough ...still my choice is the 16GA SxS shot gun to do this build on..I bought a F. Dumoulin & Co. 16-gauge side-by-side (SxS) double-barrel shotgun...it has a Greener Type cross bolt ...

I do have a W.Greener 12GA SxS Empire Model build in 1931. But I really do not have the heart to cut this shot gun..it is a sweet shooting shot gun that really shoots very accurate a..

 

[Tintin]

Gert - sounds like a fun project.

Looking forward to seeing the progress.

Mark

 

[Gert Odendaal]

Gert - sounds like a fun project.

Looking forward to seeing the progress.

Mark

Mark for sure..I really am looking forward to the project in the near future..

 

[Ray B]

I recall in bootcamp a training session where rifling was discussed. We were told the standard for firearms was a clockwise or right twist however for the Colt 1911 pistol the twist was counter-clockwise or lefthand. The reason for this we were told was that the bullets being pushed counterclockwise caused a force on the barrel and the gun to rotate clockwise. Since the training involved holding the firearm with the right hand, the twist would cause the gun to push into the holder's hand, making for a more secure grip. This theory applied to double rifles would means a lefthand twist in the left barrel would cause the gun to recoil slightly away from the face of a right-handed shooter. I know of no cases where this has been tried.