Double Rifle:Hard bullets=Barrel separation?

[skydiver386]

Looking at hunting bullets for my .450 Rigby build, I came across an article that discussed bullet hardness v barrel strain and possible barrel separation in Double Rifles. Is this real or imaginary? I do remember older bullets like the steel jacketed Hornady, solid brass bullets with no driving bands, etc , that were rumored to be hard on rifling, but never considered barrel separation in doubles as an issue.

Barrel Strain Double Rifles

Barrel Strain Double Rifles

www.b-mriflesandcartridges.com

 

[Boone66]

I am curious as well, I know some guns are proofed for steel jackets and some aren't. I'm curious about solid copper bullets in doubles and drillings and barrel separation also.

 

[Boone66]

I did not expect cast bullets to be the so high, interesting article

 

[Tokoloshe Safaris]

I think you will find a lot of proof against not a whole lot for. Myself with 50 yrs experience stay away from monolithic in old english. I would not be afraid to shoot almost any bullet in a modern quality double, but then ask yourself why? I have never had a woodleigh solid (or soft) fail me.

Lon

 

[rookhawk]

Looking at hunting bullets for my .450 Rigby build, I came across an article that discussed bullet hardness v barrel strain and possible barrel separation in Double Rifles. Is this real or imaginary? I do remember older bullets like the steel jacketed Hornady, solid brass bullets with no driving bands, etc , that were rumored to be hard on rifling, but never considered barrel separation in doubles as an issue.

Barrel Strain Double Rifles

Barrel Strain Double Rifles

www.b-mriflesandcartridges.com

450 Rigby is an extremely high power bolt action round. Due to the "newness" of the caliber, all guns barrels for the caliber will have excellent metallurgy. Hence, issues around barrel strain and separation doesn't really have relevance to the cartridge being discussed or its targeted application in magazine rifles.

If we're talking about double rifles, and specifically vintage double rifles, monometal solids can present many problems even at the far lower velocities and pressures that are relevant to double rifle calibers. Monos can be very hard, they are volumetrically 22% larger than lead core bullets of equal weight, and they may be oversized creating dangerous pressure spikes. On the other hand, some monos are soft copper gilding metal and feature driving bands that result in less surface area of the bullet engraving in the rifling. Nonetheless, its generally a bad idea to put a mono into a vintage double rifle. Stick to what they want to be fed: Softs and Lead Core Solids at correct velocity and pressure.

 

[Tanks]

I think bullets with driving bands take care of that issue.

 

[rookhawk]

I think bullets with driving bands take care of that issue.

Maybe, maybe not. Driving bands allow the bullet to slide down the bore, only the driving bands are engraved. That usually produces less pressure. However, some mono solids are really, really hard, so that doesn't completely alleviate the situation. Nosler solids for example, are brass and hard as nails. I don't recommend them in a vintage double whatsoever.

 

[Rare Breed]

Looking at hunting bullets for my .450 Rigby build, I came across an article that discussed bullet hardness v barrel strain and possible barrel separation in Double Rifles. Is this real or imaginary? I do remember older bullets like the steel jacketed Hornady, solid brass bullets with no driving bands, etc , that were rumored to be hard on rifling, but never considered barrel separation in doubles as an issue.

Barrel Strain Double Rifles

Barrel Strain Double Rifles

www.b-mriflesandcartridges.com

From my personal experience having owned a Westley Richardson DR built in 1908 in 500 NE to my Rigby 470 DR of today plus my own research inclusive of our own Rookhawk if you have a vintage rifle like my 1908 you are taking a real risk shooting mono hard bullets through them…yes they can ruin your barrels. On the other hand with the latter DRs such as my Rigby no problem or concern. For my 1908 I only shot Woodleigh. For all my others I shoot whatever I want no problem

 

[Rare Breed]

Westley Richards not Richardson

 

[JvW]

Hard bullets and old rifles are generally not a good mix. Barrel separation, overstressed rifling, and even bursts can occur, although thankfully it doesn't happen frequently. "Hard" should certainly include steel-jacketed solids as well. I know of one vintage .450 NE that burst its barrels in rather spectacular fashion after being fired with modern US-made .450 NE factory ammo loaded with steel-jacketed solids. The same thing has happened with old bolt-actions, although it is much less of a risk here due to the fact that bolters generally have thicker barrels.

Rifles with older-style rifling (Metford, Oval-Bore, etc) are more susceptible to damage as well. Graeme Wright explains the whole phenomenon very well in his book and has a whole chapter devoted to the subject.

The driving band mono has gone some way to alleviating the problem. The Woodleigh Hydro is a good example of this. I know the designer and manufacturer of the bullet very well and he went to great pains to ensure that they are safe in older barrels. As I don't have much experience with mono bullets from other manufacturers, I cannot speak for them.

This is an example of overstressed rifling in an older rifle. Unfortunately I don't have any more details.

 

[PCC600]

Hard bullets and old rifles are generally not a good mix. Barrel separation, overstressed rifling, and even bursts can occur, although thankfully it doesn't happen frequently. "Hard" should certainly include steel-jacketed solids as well. I know of one vintage .450 NE that burst its barrels in rather spectacular fashion after being fired with modern US-made .450 NE factory ammo loaded with steel-jacketed solids. The same thing has happened with old bolt-actions, although it is much less of a risk here due to the fact that bolters generally have thicker barrels.

Rifles with older-style rifling (Metford, Oval-Bore, etc) are more susceptible to damage as well. Graeme Wright explains the whole phenomenon very well in his book and has a whole chapter devoted to the subject.

The driving band mono has gone some way to alleviating the problem. The Woodleigh Hydro is a good example of this. I know the designer and manufacturer of the bullet very well and he went to great pains to ensure that they are safe in older barrels. As I don't have much experience with mono bullets from other manufacturers, I cannot speak for them.

This is an example of overstressed rifling in an older rifle. Unfortunately I don't have any more details.
View attachment 588924

You can’t go wrong by referring to Graeme Wright’s book “Shooting the British Double Rifle “. The Bible for determining what to shoot through older doubles . His other book written in conjunction with Geoff McDonald of Woodleigh Bullets is also a must have .

 

[Hunter-Habib]

The owner of Woodleigh bullets wrote me this reply on the subject:
"After a considerable amount of research, we recommend that you have the barrels hardness tested, if the barrel steel is harder than 230 Vickers (DPH), then they should be ok, if the barrels are softer than this reading, then steel jackets should not be used."

I follow another rule. Kynoch (the sole supplier of ammunition for double rifle calibers until 1982) started using steel jackets in all their FMJ solid bullets from 1950 onwards. It was the machinations of a wealthy American sportsman, Mr. Don Hopkins which indirectly led to Kynoch commencing the use steel jackets in their FMJ solids bullets. He owned a James Purdey & Sons .470 Nitro Express sidelock ejector but had dismal bullet performance with Kynoch's gilding metal jacketed FMJ solids during an elephant hunt in Kenya in 1949. So he requested James Purdey & Sons to convince Kynoch to shift to steel jackets on their FMJ solid bullets in 1950. Prior to this, Kynoch only used steel jackets for FMJ solid bullets made in one caliber- The .416 Rigby. So all British double rifles built after 1950 would be regulated for steel jacketed FMJ solids (and therefore are quite safe to use). The exception to this rule, was Holland & Holland. They stockpiled a large consignment of the old Kynoch gilding metal jacketed FMJ solids and kept regulating their double rifles with them up until 1958.

As a general rule, I avoid steel jacketed FMJ solids in any British double rifle manufactured prior to 1950. Vintage German double rifles are fine, though. The Germans began to use steel jacketed FMJ solids in their rifles (including double rifles) as early as 1912. The proof marks denote this, as well.

On the subject of monolithic bullets, I made an interesting observation. Regardless of whether or not they'd actually be safe to use (in practice), the following companies flat out DISCOURAGE the use of monolithic bullets in their double rifles:
James Purdey & Sons
John Rigby & Co.
Westley Richards
George Gibbs

Holland & Holland used to discourage the use of monolithic bullets in their double rifles until 2021. Once Beretta bought Holland & Holland, they changed their policy and now advertise their new double rifles as being perfectly safe to use with monolithic bullets.

Many of the old (and now defunct) Belgian gun making firms all strongly discouraged the use of monolithic bullets in their double rifles. I've personally seen an Auguste Francotte .470 Nitro Express sidelock ejector which developed overstressed rifling after being used with monolithic bullets. Marcel Thys used to discourage the use of monolithic bullets in their wares, all the way until the company closed down.

My friend, Mark Sullivan (of Nitro Express Safaris) actually had a Joseph Lang .450 Nitro Express boxlock ejector's barrels separate four inches from the muzzle after firing the old blue colored Barnes X bullets through them.

Modern double rifles (such as those built by Heym or Verney Carton or Merkel or Rizzini) are explicitly stated by the manufacturers as being safe to use with monolithic bullets.

 

[zephyr]

Attached find pressure and strain data compiled by Michael McCorry and Sam Rose using his 470 with various DR bullets found on the market Perhaps some empirical data will help you with your decision You will find the lowest pressures belong to CEB and Northfork bullets Woodleigh's Solid had yet to hit the market
https://www.b-mriflesandcartridges.com/barrel-strain-double-rifles