Rifle age and modern ammunations.

[dersark]

Hello all,
My 375 H&H is almost 100 years old rifle by documanted history, The Ammo I used so far are 270 and 300 grains and are new modern ammos,
My knowledge regarding rifle ammo componenets are limited. Base on what I read or heard moderen ammos should not be used in old rifles.
The information punchued on the side of barrel says Cordite 56-300, I appreciate an expert opinion what that means and if it is safe to continue using modern ammo in this specific rifle,
Lazik

 

[JimP]

Ammo manufacturers have the capability of loading ammo for any vintage of caliber for any rifle. And while they could load it hotter for modern rifles they keep the pressures at the industry standard for that caliber. Mostly for liability issues.

Your rifle will have zero problems shooting modern ammunition.

II believe that Cordite 56-300 just means that the cartridges were loaded with Cordite powder as most older British made the rifles were.

 

[rookhawk]

Hello all,
My 375 H&H is almost 100 years old rifle by documanted history, The Ammo I used so far are 270 and 300 grains and are new modern ammos,
My knowledge regarding rifle ammo componenets are limited. Base on what I read or heard moderen ammos should not be used in old rifles.
The information punchued on the side of barrel says Cordite 56-300, I appreciate an expert opinion what that means and if it is safe to continue using modern ammo in this specific rifle,
Lazik

The Original 375H&H load was 58 grains of cordite with a 300gr bullet. Marked 58-300.

I would double check your rifle to verify if it says 58-300 or if it actually says 56-300 like you stated.

Possible conclusions:

1.) You are incorrect
2.) The rifle isn't a 375H&H belted magnum, but rather a different .375 caliber
3.) Your rifle was proofed in the UK for a lower pressure than the standard in which case you'd need to load it for that lower pressure. (Standard pressure is 62,000psi)

 

[dersark]

Base on what is written on the barrel is Cordite 56-300 MAX
375 Magnum 2.85

 

[rookhawk]

Base on what is written on the barrel is Cordite 56-300 MAX

56-300 2.85" .375 Magnum may then be an entirely different caliber than the standard 375 H&H Magnum. It would be odd, because 58grains of cordite with a 300 grain bullet and a 2.85" cartridge length would be the original 375HH proof house specifications at 62,000psi.

If you have some unique aberration, it would be something quite odd since the very first UK proof house specs set in 1911 were as I described.

You'd have to figure out definitively that the chamber and bore are indeed for the 375H&H and then you'd need to deduce what the pressure max would be for 56gr of cordite shooting a 300gr bullet out of a H&H case. It would be less than 62,000psi by quite a bit, but cordite is an extinct powder so quickload wouldn't be able to extrapolate the lower pressures.

You would have the first magazine rifle of its kind I've ever heard of that had this scenario. Light-loadings and lower-pressure proofs are not uncommon in rimmed single shot and double rifle calibers, often including lighter bullets, lower velocities, and shorter case lengths, but I've never seen that for 375HH.

 

[dersark]

I am firing 375 H&H for past 20 years without having any issue, is it possible.
it can be 378 magnum 2.86 ?

 

[rookhawk]

I am firing 375 H&H for past 20 years without having any issue, is it possible.
it can be 378 magnum 2.86 ?

378 weatherby did not exist when cordite proof marks were present. Further, a 378 wby would be HIGHER pressure, not lower.

Please get a piece of chalk and rub it in the proof marks and take a close pic to make 100% positive its 56-300 not the normal 58-300 that is customary on vintage English 375H&H rifles.

If it is indeed 56-300 marked and if it chambers and fires a 375HH, then you'd need to develop a low-pressure 300gr load to honor the initial lower pressure designation of the rifle.

 

[dersark]

Ammo manufacturers have the capability of loading ammo for any vintage of caliber for any rifle. And while they could load it hotter for modern rifles they keep the pressures at the industry standard for that caliber. Mostly for liability issues.

Your rifle will have zero problems shooting modern ammunition.

II believe that Cordite 56-300 just means that the cartridges were loaded with Cordite powder as most older British made the rifles were.

378 weatherby did not exist when cordite proof marks were present. Further, a 378 wby would be HIGHER pressure, not lower.

Please get a piece of chalk and rub it in the proof marks and take a close pic to make 100% positive its 56-300 not the normal 58-300 that is customary on vintage English 375H&H rifles.

If it is indeed 56-300 marked and if it chambers and fires a 375HH, then you'd need to develop a low-pressure 300gr load to honor the initial lower pressure designation of the rifle.

Thank you all for the help,
Okay, I will try what you recommend in the morning to see it is 56 or 58
Lazik

 

[grand veneur]

Hello all,
My 375 H&H is almost 100 years old rifle by documanted history, The Ammo I used so far are 270 and 300 grains and are new modern ammos,
My knowledge regarding rifle ammo componenets are limited. Base on what I read or heard moderen ammos should not be used in old rifles.
The information punchued on the side of barrel says Cordite 56-300, I appreciate an expert opinion what that means and if it is safe to continue using modern ammo in this specific rifle,
Lazik

Some things about the proofing of old British rifles are often confusing. As @rookhawk told you, the classic proof load for the cartridge 375 H&H Magnum is slightly higher. I own a double rifle caliber 577 Nitro Express proofed 1909 initially CORDITE 90-650 MAX, then again CORDITE 90-750 MAX. The previous owner in Kenya used the full load CORDITE 100-750 MAX in it for years without any problems. I do that too. In my opinion, the proof houses often played it safe when pressure was concerned, especially when it came to the use of Cordite in the tropics. For this reason so-called Tropical loads were also delivered. Whether to use the full load or a reduced load is up to each to decide. The condition of the rifle and the concept of its building are particularly important. Cordite is a very fast burning powder that primarily develops its maximum pressure initially, on the contrary to the more progressive powders used nowadays to load the cartridge 375 H&H Magnum.

 

[Sarg]

Would be nice to see the whole rifle, the bit we can see looks very nice.

If it is a Mauser 98 type action in good condition, you will be fine using any modern factory loads !

 

[uplander01]

Have the chamber cast and don’t guess. Also don’t shoot non ribbed monometal bullets in the bore, the barrel steel from that vintage may not take the pressure in the bore.

 

[Hunter-Habib]

Hi, Lazik.

It’s perfectly safe to shoot modern ammunition through your vintage .375 Holland & Holland Magnum, as long as the muzzle velocity doesn’t exceed 2530 FPS. Just take care to have the hardness of the barrels tested for any English rifle made prior to 1950. If it's above 230 Vickers, then you can safely run steel jacketed FMJ solid bullets in it. Otherwise, stick to copper jacketed bullets like Wim Degol Starkmantel/Vormantel or alloy jacketed bullets like the Swift A Frame/ Break Away Solid. Avoid monometal bullets (especially the unbanded variants) in this rifle, except for the Woodleigh Hydro (which is specifically designed to produce less barrel pressure than most other monometal bullets or even steel jacketed FMJ bullets). All English rifles built after 1950, will be perfectly safe to use with steel jacketed FMJ solid bullets and will have a barrel hardness that ranks higher on the Vickers scale than 230. Because starting from 1950, Eley-Kynoch (the ammunition brand exclusively used by English gun makers to proof their wares until 1970) began to employ steel jackets for their FMJ solids.

Off-Note: Even if they were built before 1950, John Rigby & Co. rifles chambered in .416 Rigby or .350 Rigby Magnum are safe to use with steel jacketed FMJ bullets. Because Rigby had Kynoch produced steel jacketed FMJ solid ammunition for these two calibers ever since their inception. Thus, all Rigby rifles manufactured in these calibers (regardless of vintage) would have been proofed with steel jacketed FMJ solids.

 

[Huvius]

So you've been shooting modern 270gr and 300gr ammunition in your rifle with zero issues?
If you have normal bolt lift and extraction and your fired primers look as expected then you have nothing to worry about.
The engraving is very Jeffery style. Looks to be a very nice rifle.

 

[GeorgeGibbs505]

Some of the rifles and ammo were marked for Tropical Load. Possibly could be the reason for 56-300.

 

[rookhawk]

Just a point of contention. The entire purpose of a proof mark is to "prove" something is safe for a particular load. It's your warranty. You can always handload for anything you want, but then the onus and liability is solely yours. It's always best to adhere to the proof marks and then purchase or make ammunition in compliance with what is "proven" safe. If the rifle in question indeed is 56-300 proofed, it is not proven safe with modern factory 375HH ammunition. Rather, we start throwing out ideas like "should be okay" or "probably a good gun that will hold up" rather than making declarative and definitive statements like "you're shooting the correct CIP/English factory ammunition determined safe for your rifle".

 

[Huvius]

Just a point of contention. The entire purpose of a proof mark is to "prove" something is safe for a particular load. It's your warranty. You can always handload for anything you want, but then the onus and liability is solely yours.

I agree to a point.
On a 100yr old rifle the proof marks mean exactly zero - other than identifying what the rifle was originally proofed for.
They are no warranty. They are just information to consider.
They tell you nothing of the gun's current state or even if it would again pass proof if submitted today.

I do agree that any liability is solely the owner/shooter's.

 

[dersark]

Thank you all for your knowledgable informative advices.
I doubled check and is 56-300
Lazik

​

 

[Huvius]

Lo and behold!
Here's another 375 (Jeffery in this case) stamped with 56-300 cordite proof mark!

WJ Jeffery 375 H&H Magnum Bolt Rifle, Scoped, Cased for sale

WJ Jeffery 375 H&H Magnum Bolt Rifle, Scoped, Cased for sale online.

www.gunsinternational.com

 

[MS 9x56]

Hello all,
My 375 H&H is almost 100 years old rifle by documanted history, The Ammo I used so far are 270 and 300 grains and are new modern ammos,
My knowledge regarding rifle ammo componenets are limited. Base on what I read or heard moderen ammos should not be used in old rifles.
The information punchued on the side of barrel says Cordite 56-300, I appreciate an expert opinion what that means and if it is safe to continue using modern ammo in this specific rifle,
Lazik

Not sure who told you that. I shoot mild handloaded with modern bullets in 2 100+ year old rifles with no issues. You just need to keep the pressure down to design specs. Dont try to hot rod your ammunition. Just keep an eye out for pressure signs such as flattened primers, hard or sticky bolt lift.