Could it have been primarily developed for the American market?

The Super .30 bore size was adopted by H&H after the British were influenced by the US .30/06 in WW1 France.
the rimless version for bolt rifles was orig. a patented propriety cartridge available only in exclusive H&H rifles,
(or selectively by other makers with H&H permission)
The belted casehead design originated not from the .375HH of 1912, but from the .400/375 BNE, introduced in 1905.
(The H&H shop offered bolt rifles in .400/375 BNE using the Austrian supplied Mannlicher Schoenauer action.)

with the traditional .300HH, one has an American bore, British design belted feature case, chambered in a German Mauser action.


Its also interesting to note that Savage at one time designed & chambered the .303 Savage Rimmed.

The 303 Savage is and always has been, a 30 caliber cartridge, not a true 303 at all. Winchester had the very similar 30/30 ,Savage simply dropped the last zero and called it the 303.

Nope not 9.5x57 MS / that was a rimless
H&H copied it from their own in the form of the 400-375 H&H.

As to the question of developing the 300 for the US market / no H&H were having to compete with the euro's who's guns and calibers they were using as their own as was every other British gunmaker at the time.

The question about H&H choosing a 7.62mm (308) bullet vs a 7.7mm (311) bullet is also interesting and has to be viewed in terms of timeline set to the backdrop of the development of nitro propellants in GB.

This BP to stick nitro to flake nitro was a big deal for the Brits. The euros did not have the stick nitro problem.

It started with the 375 Cordite with its 270 gr bullet intended to give a bigger impact than the 303 for similar velocity. The 270 gr bullet had a velocity of about 2000 fps compared to the 303's 2036 fps for a 215 gr bullet.

The bullet drop on the 303 was 18 inches at 200 yards and 270 gr 270 dropped about 20 inches.

The 200 gr velopex bullet of 1906 of 200 gr did 2400 fps from the 375 cordite and and dropped only 15 inches at 200 yards.

In the meantime they also come up with their 450-400 3 1/4 which when loaded with nitro in stead of BP gives a velocity 2100 fps on a 370 gr bullet

The 303 was the first H&H small bore derived from the British military version but loaded with Rifleite and a patented H&H bullet called the "patent peg bullet"

The 303 was a problem child as we see from the military development.

It was slow when compared to the euro small bores like the 7mm Mauser.

Also it was rimmed and not really suited to magazine rifles such as the Mauser.

Mauser did build rifles in 303 for Rigby but it required a special action with special slanted magazine.

The 303 really only became an item after the development of the Mk7 variant in 1910 with the 174 gr bullet. for the first time the brits could compete with the euro's in battle

H&H used the 6.5 Mannlicher ( 256 cal) as a fast small bore and this outran the 303.

So to counter the rimmed issue and to get a faster cartridge with more downrange energy that the 303 they came up with the 400-375 which was in the development around 1902 and patented in 1904. They used the 400 case of the 450-400 stuck removed the rim and stuck a belt on it and suddenly they had a 375 that would run at 2050 fps for a 320 gr bullet using 50 gr of nitro. This was developed by FW Jones of the company SPAC of Barwick and Henry Holland of H&H.

Jones and Charles Ross develop the 280 Ross in 1906. This cartridge was fast really fast, in fact when Halbe and Gerlich got a hold of it in 1926 stoked it up with German flake and shot from 36 inch Mauser they ran the 100 gr 280 bullet off the speed map ! 3900 fps tested at the Hallensee proving ground

H&H needed a counter for the 280 so they took the 400 -375 and necked it down to 7mm ( actually not the same 7mm as the german 7mm but slightly bigger) So in 210 we see the 275 H&H come about. this got a respectable 2600 fps from a 140 gr bullet. The case capacity was bigger than the original 400-375.

From the 275 came the 375 H&H in 1912. This was their big achievement. They could milk a velocity of 2800 fps from a 235 gr bullet from the Mauser rifle.

the war now intervenes and after the war in 1919 they come up with the 240 apex. This is a 6mm based on a necked down 375. This cartridge was deigned to get to the 3000 fps barrier for a 100 gr bullet

in 1925 they neck the 375 down to a 30 cal and this became the 300 H&H. 3000 fps on a 150 gr bullet.

The reasoning for the 300 was to extend the energy of the 275 to longer ranges.

Much to H&H's credit and huge feather in their cap comes in the form of the famous win by US shooter Ben Comfort at the Wimbledon cup in 1935

Okay -- all of what you just said up to the year 1925. Then, I ask again, why did they design the .300 H&H Mag instead of the .303 H&H Mag when they tapered and necked down the .375 case?

Because they ran like everyone else after velocity and muzzle energy numbers.

They competed in public trails for market share just like anyone else.... and they did it using math. Their products and tests were published and scrutinized in public forum.

Unlike modern reloaders who take existing cases neck it up or down look at velocity numbers and wonder about pressure the cartridge designers of yesteryear modelled their ballistics to mathematical models and they built their guns accordingly.

The eneginering dudes at Krupp and RWS used mathematical models to come up with the numbers and then built cartridges and guns to follow.

We tend to forget that these guys were patent holders, they were at the forefront of ballistics development. Reputation did not come easy ! The history of cordite shows exactly how difficult it was.

H&H made a big deal of this because each and every one of their inventions came in two forms, one load for double rifles ( and some required beefing up) and the other for magazine rifles.

They ran exhaustive tests to ensure that their guns did not blow up.

To boot they had the whole DWM catalog on their doorstep to compete against ! The euros came up with all the firsts.

They had the spitzer bullet, they missed the stick cordite fiasco and they had the gold silver and bronze all sewed up on very level of small arms development.

The americans were wallowing in clouds of BP smoke wondering what happened when the Mauser 7mm pounced on them from afar. The british had their arses handed to them in the Boer War again at the hand of Mr Mauser and his itty bitty 7mm

Yes DWM !!!! All fueled up on German flake ! Though the US market was lucrative and huge the challenge came from Europe.

I understand and can accept everything you said. Yet that still does not address the question. The .303 caliber bullet underwent tremendous R&D. It would have been very easy for H&H to use the .303 bullet and I am sure there was already ample machinery to produce .303 caliber barrels.

1889 - .303 Mark I and Mk II service cartridges with 215-grain, round-nose bullet

1898 - .303 Mark III, the 215-grain bullet with jacket cut back to expose lead in the nose. Follwed by similar bullets in Mk IV and Mk V

1904 - .303 Markk VI, round nose bullet similar to the Mk II adopted because Hauge Convention outlawed expanding/hollow-pointed bullets

1910 - .303 Mark VII, a 174 grain pointed bullet with flat-base, a MV of 2440 fps, and a whopping ballistic coefficient of .467.

Nitrocellulose versions of the .303 Mark VII were introduced during World War I as the Mark VIIZ and bullets weighed 175 grains

If you were to take a .300 H&H case, load it with a .311 caliber bullet, and shoot it through a .311 barreled rifle it would perform just as well. There had to be another reason that H&H went to all the trouble to develop and refine the .300 Magnum (belted and flanged) in .308 caliber instead of .311 caliber.

.

.....along the same line of question,......-why didn't H&H use .416 instead of .411 for its proprietary .400H&H...?

Do the math:

If you are trying to reach a velocity number with certain energy level at range given a pressure limit in a usable gun you end up with certain calibers that are "better than others"

It is not by chance that certain calibers dominate the F1 competition ! why do people shoot 6.5s and not 311's ! To get a 311 to shoot at long distances and retain velocity you are going to have a very heavy long 311 cal bullet and to get enough velocity from that heavy bullet it's going to need one huge case and a huge gun to do the job! That means huge recoil !

The 303 had a tarnished record, not because of caliber per se but simply because of timing in gun design advances.

its basic ballistics science, and they invented it. ( actually the euros did)

Different issue Trax. The .411 makes perfect sense to me because the 450/400 Nitro Express uses .411 diameter bullets. To my way of thinking, the .400 H&H is the rimless version of the 450/400 just like the .300 H&H and .375 H&H Magnums are rimless versions of the .300 FL and .375 FL Magnums. Gun rag contributors always told us the .404 was the rimless version of the 450/400 but they were just fooling us. The .404 uses a .423 caliber bullet, not a .411 caliber bullet. Going to .416 wouldn't have produced a rimless version of the 450/400 either. Not until the .400 H&H was there a true rimless compliment to the 450/400 round.

Back to the .303 and the .300. I bet if you took an old P14 and rechambered it for a .303 H&H wildcat the cartridge would perform nearly identically to the .300 H&H.

Here is the key to the riddle Both in the field of internal ballistics and the issue of terminal ballistics.



If we look at the global picture and look at the history of internal ballistics we see that all we have now stemmed from this graph.


Wal Winfers series of works on the British single shot rifles show all of the developments that relate to this time of transition from a British perspective. it was a fascinating time!

The Euros were way ahead of the curve, their military's asked for better weapons and their ballisticians delivered.

They did not have existing cases to form and modify, they designed them from scratch !

The military asked for rifles and cartridges with specific requirements and they used their internal ballistics math models used to design cannons to design and ultimately build the guns to deliver the required ballistics.

The limits were obvious, size , recoil and weight of gun to handle the required ballistics setpoint.

Yet the Germans locked themselves into 8mm as their primary bore of choice for many decades, first .318 in 1888 then .323 after 1905. All of that wonderful research and development was to improve the 8mm cartridge and not to design the absolute best caliber/bullet/cartridge solution. If so, they probably would have come up with something more like the French 7.5 (a .31 caliber) or the Belgian/Argentine 7.65 (a .313 caliber).

The German MOD is hardly on trail here for choosing the M88 case as their platform.

At issue is why and how the H&H cartridges came about.

It is historical fact that the British trade were substituting BP with Stick Nitro in previously BP designated cartridges. ie large case large bore cartridges. This brought about its own problems.

Almost all of them took small bore Euro cartridges and redesigned them to imperial caliber nomenclature, some going so far as to put proprietary names to them.

So prevalent was this practice that the British trade became Mausers biggest single customer and actually saved Mauser from bankruptcy.

In the face of this historical background H&H forged ahead for it's stake in the shooting world with some of the world most significant developments in the form of the 400-375 and its spawn.

We should not forget that a whole family of current US designed cartridges all belted owe their origins to the work of FW Jones and Henry Holland.

All good stuff, ALF. But the .300 H&H was developed two decades after the transition to nitrocellulose powders. I still see no good reason Holland & Holland didn't just neck the .375 magnum case down to .311" for the .303 bullets. I know they had to have a reason. I don't think we have hit upon it.

I can't help but think they recognized the possibilties which existed in the huge US marketplace and accepted the widespread use of the .30 caliber in the US. The one thing I find interesting is that Winchester chose to chamber the 300 H&H instead of going with the 30 Newton. The Newton was already being produced by WCC, it fit the magazine of the 54 and the later model 70, and had the potential to outperform the H&H. Of course, Winchester had to open up the Model 70 to take the 375 anyway so that could be the reason (I had the opportunity to buy, cheap, one of the very first 375's Winchester made. It was one of six they produced with a stahdard weight 24 inch barrel. The other five were returned to Winchester and re-barreled so this rifle was unique. Demonstrating the business acumen which was to become my trademark, I passed on this one). I suspect that Newton had antagonized the guys at Winchester and that could have been another reason.
If Winchester had opted for the 30 Newton, we would never have seen a 300 H&H in America. We might not have seen any of the belted magnums unless Weatherby still decided to go that way. We'll never know. Regards, Bill

This is one of those "WHY ask Why" questions....no diss or flame intended.

The actual reasons are lost to history because all the individual's involved in the decision making processes are long dead and all we can do now is to conjecturize based on our incomplete knowledge but with a fair amount of "logical in hindsight" reasoning as to the whys and wherefores...

Simplistically speaking...It is what it is because that's what it is...and we can ask the "why" question forevermore and all we end up with are personal observations based on incomplete but very useful knowledge and a whole lot of pot stirring.

My question is "WHY" an "odd" calibers like the .311, .425 and even the .257 and .308??? "WHY" not a .300 or .400 or .250???

There were probably very good reasons at the onset of those calibers that seemed reasonable to the developers but seem a bit strange to todays shooters.

Go figure.

No offence to anyone however Its because the majority of todays shooters have no idea of how internal or even intermediate ballistics work.

The military cartridges that preceded sporting cartridges were designed to order to satisfy certain ballistics criteria within specified platform constraints as requested by the military.

They literally designed cartridges from the ground up to satisfy a specific request. usually the delivery of a bullet accurately and consistently to a specified range delivering a specific energy value at that range. The delivery system had to be able to do this a thousand times over consistently without to much wear or failure.

Gun platform constraints being that of shootability, portability and overall reliability under certain conditions were mandated by request.

Shootability was and is important. Under combat conditions a 30-06 is deemed to much cartridge for a GI weapon.

It is then no surprise that for a general infantry weapons common themes evolved.

The caliber fell somewhere between 7mm and 8mm with 6.5 and larger than 8mm as outliers.
Case size to followed this pattern again most falling within the realm of the German M88 case capacity and the 30-06 capacity. When case capacity was exceeded like in the 276 Enfield or the 280 Ross the shootability of the gun became a problem. Even the 30-06 was deemed to much cartridge for a GI weapon.

To attain downrange capability Sectional density windows within the caliber range became obligatory , you could not improve this because of the 7 deg twist angle limit of the bore. this meant L/D ratio limits for each and every bullet used no matter what the caliber.

So within these constraints and doing testing caliber became something one could manipulate to attain a desired downrage capability. Hence the choice of odd calibers or in the case of certain cartridges " odd " bullet weights.

quote:

It is not by chance that certain calibers dominate the F1 competition ! why do people shoot 6.5s and not 311's ! To get a 311 to shoot at long distances and retain velocity you are going to have a very heavy long 311 cal bullet and to get enough velocity from that heavy bullet it's going to need one huge case and a huge gun to do the job! That means huge recoil !

This may well be the reason why the Swedes opted for a 6.5x55mm cartridge. The recoil was lower than .303 Br and 30-06 Spr. Sweden's military loaded their long round-nose 6.5mm m/94 projectile of 156 gr to a muzzle velocity of 2,379 ft/s right up to 1940, but change the load in 1941 to a 140 gr Spitzer bullet at 2,625 ft/s.

It is easier with a 6.5mm bullet to obtain a high BC with a lighter bullet than with say a .311 bullet. The 260 Remington is another mild recoiling cartridge using a .308 Win necked down case (51mm) that is even smaller than the 6.5x55 Swede. Lapua has gone even smaller with their case (47mm) to come up with a 6.5x47 Lapua.

Santa Claus

Maybe from a marketing standpoint "Three Hundred H and H" just sounds sexier than "Three oh Three H and H". Cartridge names that flow off the tongue seem to fare better than oddballs.They were smart enough to know the big market was the USA.

quote:

Originally posted by Grenadier:
Okay -- all of what you just said up to the year 1925. Then, I ask again, why did they design the .300 H&H Mag instead of the .303 H&H Mag when the tapered and necked down the .375 case?

quote:

Originally posted by ALF:
. . . you could not improve this because of the 7 deg twist angle limit of the bore. this meant L/D ratio limits for each and every bullet used no matter what the caliber.

Could you elaborate on this?

Maybe because they had a better source for .308 bullets.

Muskegman:

Ok pardon me for lack of brevity but this needs some explaining which may be difficult.

We spin bullets to make them stable.


The rate of twist ( angle tof twist) for each caliber of barrel determines the amount of spin needed to satisfy the gyroscopic condition where the gyroscopic force is equal to or greater than the overturning force caused by drag.

Munk's gyroscopic formula dictates this.

If we assume a Gyroscopic force number of at least 1.3 as calculated by Munk's formula to be necessary to account for possible atmospheric pressure conditions a bullet in flight may encounter, we see that for each bullet there is a minimum barrel twist rate that would satisfy this SF = 1.3 number.

You can make the rate of twist faster but not less than this limit.

The question is how fast can you go with rate of twist.

To get twist, rifling is cut into the bore and the angle at which the rifling is cut determines the rate of twist expressed as one turn per X inches. This is the angle of twist.

But here lies the rub.

If the angle is to big ( to acute) the bullet will slip forward stripping the grooves cut into the bullet before starting to rotate.

The twist angle limit is about 7 degrees If you make the angle bigger than 7 degrees it is counter productive ( this is the reason behind the use of gain twist barrels)

So it means we have a window of twist rate that is necessary for each caliber to function:

On the one side of our window the rate of twist ( twist angle) to give us the SF value of 1.3 and on the other the limitation of angle of twist of 7 degrees.

This has a further implication and that has to do with projectile design.

For obvious reasons it is beneficial to long range shooting (accuracy and precision) that we choose the best (BC) Ballistic coefficient projectile possible.

From a physics point of view BC is defined by the following formula.

BC = Sectional density / factor of form

or

BC = SD/i

But we have this window of rate of twist that we have to operate in for each bullet.

For purposes of design we can express our projectile in terms of a length to diameter ratio. L/d

Using Munks formula we see that we can calculate maximum L/d ratios permissible to satisfy the conditions of the rate of twist window.

Simply put you can make the projectile only so long and no longer to satisfy the rate of twist limit and to get the best BC.

So in essence we have BC limit , we have rate of twist window. we have L/d limits, all in effect caused by limits in sectional density.

SD is the determinant !

So I did some calculations for a 458 cal barrel







So to give some clarity to the above graph:

Given our limits for the 458 caliber we have a twist window of between 1:15 on the slow side and between 1:11 and 1:12 on the fast side.

Making a 1:10 twist barrel for a 458 makes no sense because at 1:10 the angle of twist is 8.188 degrees and the bullet is going to slip. Actually it does if one looks carefully at some pictures of bullets posted by some members on AR

The maximum bullet length for this window is 2.29 inches or a L/d ratio of no more than 5

Practically one may already run in pressure problems on the 458 cal at a L/d ratio because the bearing surface on a bullet 2.29 inches long is huge.

This friction incidentally was the limiting factor on bullet weight when Koos Barnard came up with his massive 3 inch african express.

Most criteria of sporting cartridges comes back to profitability. I'd wager that H&H went with .308 caliber because they thought they could sell more of them that way, and nothing more.

quote:

Originally posted by Grenadier:
Okay -- all of what you just said up to the year 1925. Then, I ask again, why did they design the .300 H&H Mag instead of the .303 H&H Mag when they tapered and necked down the .375 case?

I think that's a very good question. Whatever the answer, I'm quite confident that the decision by Holland to use .308 rather than .311 diameter has absolutely nothing to do with the smoke spewing from Alf's stack. (If he thinks that a .308" bullet has remarkable advantages over a .311" bullet he should just see the marvels wrought by a .305" bullet!)

It may well be that the ".303" diameter bore was considered a military bore (British .303, Argentine 7.65, Russian 7.62x54), while the ".300" bore was regarded as a sporting rifle bore (this, despite the existence of the American .300-bore Springfield.)

Or it may have just been a trend of the day, as I don't think that any new .303-bore cartridges were developed as late as the .300 H&H, other than perhaps the 7.62x39 which came about in the rather insular USSR and used the traditional bullet size of their standard infantry round.

quote:

Originally posted by Grenadier:
Could it have been primarily developed for the American market?

Considering you are an actual H&H customer with a rifle in .300,
why don't you contact H&H to ask them if they can explain their decision of .308 bore?
Maybe they have an insightful story to tell regarding their development of the Super .30
that we have not heard before.

I know why I decided on a .308 bore for my rifle.

Anyone could ask regardless of what kind of firearm one shoots. But, I doubt that any of the great grandfathers of any of the current H&H employees were involved in the decision, and by strange chance if they had been, would have passed that information three generations down to them. If the reason for choosing a .300 H&H vs .303 H&H was part of Holland & Holland's recorded history surely we would have all read about it years ago.

That said, I already intended to ask them at the next opportunity.

Now you are simply assuming that H&H dont any longer know why the selected .308 bore.

Im pretty sure they still know why they developed certain features in their famed sidelocks,
so why would they now be ignorant as to why they developed a patented protected proprietary round with .308 bore?

If you are prepared to ask the question to AR, it just baffles that you don't see any point to ask the same question
to the H&H rifle & cartridge company that developed and patent protected the round.

You didn't read the last line.

The question just popped into my head a couple of days ago. I had never thought about it before.

Your last line was added a little later by you, otherwise I would not have said what i said.

anyway my main point was, That I would not rashly assume that H&H of today doesn't know why
H&H of 90yrs ago selected .308 bore..... id wait till they told you that themselves.

Do you think it would have anything to do with availability and restrictions on components of "War Materiel?"

The 303 brit being the British Military arm of the day... Would there have been a ready supply of bullets in 311 available to them in the sizes they needed for the 300H&H?

The US and Switzerland were the only ones using 308 at the time - and both were "Neutral" politically....

The *OTHER* logical thing that pops up is.... With the 308 groove - you won't get bunches of folks trying to convert Enfields, Mannilichers, and Mosin Nagants over to the 300 H&H just to see if you can stuff it in there..

Thanks

Fascinating speculation with stunning technical information. I'm waiting for someone from Holland & Holland to provide the definitive answer. I'm enjoying the thread even though I don't know why the sun rises in the east. Why not the North.

quote:

I'm enjoying the thread even though I don't know why the sun rises in the east. Why not the North.

LMAO


Santa Claus

quote:

Originally posted by Pancho:
Fascinating speculation with stunning technical information. I'm waiting for someone from Holland & Holland to provide the definitive answer. I'm enjoying the thread even though I don't know why the sun rises in the east. Why not the North.

In other news, the magnetic north pole is actually the south pole. Or every magnet is wrong.

Just a few corrections, not that it matters:
the 9.5x57 MS and the 400-375 H&H are two entirely different cartridges.
The 9.5x57 MS, introduced possibly in 1908 and possibly by the British, shoots .375" bullets and uses a x57 case.
The 400-375, introduced in 1905 H&H uses a belted case, has a very long neck, and also uses .375" bullets. Brass can be made from .240 Weatherby brass.
Also, the 300 H&H, or Holland's Super 30, was introduced around 1920. It wasn't until 1925 that it was introduced in the U.S. as a factory loading.

Styersteve:

Clarification:

First of all H&H list in their 1904 catalog the 375 Cordite Express:

Not to be confused with the 400/375 nor the 375 Rimmless express

This is a Flanged tapered straight wall case 375 offered as a single shot falling block as a double rifle and lastly as a bolt action Mannlicher Model 1895 Dutch rifle.

It was introduced in 1899 and first two rifles produced were for the King of Italy in 12 March 1900.

They were built as pair of Royal Doubles.

The 400/375 case is patented on 20/12/1904 and is belted. This is the invention of FW Jones and Henry Holland and this is the parent case for all the subsequent H&H belted magnums.

Patent Number 27912

The first production of ammo known as the 400/375 is announced by H&H in 1905

The interesting part of this is that the rifle this cartridge is built on is a Model M 1903 Mannlicher and H&H actually refers to it as the Holland Schoenauer, the first rifle to be produced in this caliber was H&H rifle number 24397 regulated on 19/08/1907.


The 375 Rimmless nitro express AKA 9.5x57 MS was not a British invention. Though after the Mannlicher involvement with the 400/375 it was decided to load a rimless offering for the MS 1903 rifle in 375 thus the invention of the 9.5 x 57. We must consider that their was nothing home grown in Britain that resembled the M88 type case shape in the UK. They were still stuck in the world of large case capacities.

It hailed from Styer's engineers for the M1903 action. They designed 3 cartridges for the M1903 two share the same case and the third stands all on its own. ( von Mannlicher had no hand in this cause he died in 1904 however his patents were still valid and used by Styer )

The 8x56MS the 9x56 MS which share the same case and the 9.5x57 MS which has a case all to itself.

The 9.5MS is larger than the M88 case

George Roth of Vienna loaded for this from 1910 under their own case number. After WW1 Roth ceased to be but they lived on ultimately ars part of Brno and under the PS brand Povaske Strojarne .

DWM had their own case number for it. RWS loaded for it . Hirtenberg which was a offshoot of G Roth amongst others.

Holland and Holland did not market this under their house brand brand !

Other British companies did offer the 9.5 MS rifles under their brand as a 375 Rimless Nitro Express and Both Eley and Kynoch loaded for it under that name until 1950.


Just to add to the confusion:

The famous H&H case presented as the first Belted case is in dispute:

George Roth of vienna patented a belted case June 28 1890 The Roth looks very much like the H&H case of the 400/375

Then there is a similar case the Accles double rimmed case of 1889.

Then off course there is the Belted case of Sylvester Roper of 1866 from Connecticut in the USA

Now back to the 300 Super:

The 300 H&H was successor to the 275 H&H.
Why: Pressure !!!

The 275 H&H suffered a serious problem and that was pressure ! Remembering that they were loaded with Stick cordite The British load for double rifles gave a pressure of 19 tonnes and the Rifle Load 20.5 tonnes. ( 2800 fps 160 gr bullet) Neither Double or Single Shot rifles could withstand these pressures, it burnt barrels very quickly and the doubles shot loose very quickly.

The American loaded this cartridge to about 52000 psi.

The problem for the Brits were the tropics.

Many of the original 275's had to rebarreled to other calibers.

So they went 30 caliber by necking the 375 H&H down to the 300 case shape they could bring the pressure down to 17 1/2 tonnes for 2700 fps on a 180 gr bullet.

The 300 Super was chosen to succeed the unsuccessful 275 H&H !

Based simply on ballistics !

They could not afford having a cartridge that caused problems. The H&H Ledgers show that some 275's were brought back for rebarreling

Good info. Especially about the .375 Flanged Nitro Express 2 1/2", which, for some reason, a lot of folks confuse with the .375 Rimless Nitro Express/9.5x57 MS.
Also, good stuff on the earlier development of belted cartridges.
Couple of points, though.
Most of the British gun makers (Fraser, Evans, H&H, etc) simply bought Mannlicher-Schoenauers, either as barreled actions or just as actions. Then they barreled as they saw fit. I have found no correlation between Steyr and the development of the 400/375 H&H. Also, my records show Henry Holland patented the 400/375 in 1905, as per the IAA.
Also, and I am measuring as we speak, the 400/375 has a diameter of .453" ahead of the rim, the same as the nominal specs on the .240 Weatherby Magnum. That's the only other belted case I can think of that the 400/375 H&H might have spawned. The .375 H&H, .300 H&H, et al measure @.513 ahead of the belt.
I've never seen it mentioned before but I'll bet ole Roy Bee must have come across a 400/375, necked it down to .24 caliber, blown out the shoulder, and "voila", had his 1968 hyper-velocity .24 cal. Case lengths are the same at 2.5"
There is a lot of contention that the Brits developed a cartridge eventually called the 375 Rimless Nitro Express (2 1/4") around 1908. The folks at Steyr picked up on it and, in 1910, came out with their Mannlicher-Schoenauer Model 1910 in 9.5x57 MS (also called by several other designations). Same wine, metric bottle.
No one knows for sure but it makes for good debate.

I do not believe that the 9.5x57 MS was British Designed Not by Eley and definitely not by Leslie Taylor of WR

Why do I claim this: If LT had anything to do with the 9.5 MS it would have been listed !


WR was very big on their marque value, they prided themselves on what patents they held ! They proudly proclaimed and marketed their patents !

So in the 1912 centenary catalog WR make distinction between two "systems" for the same 9.5 MS.

The one is the 9.5x57 MS bore in Mannlicher Schoenauer , they show the 9.5 as a MS cartridge in the illustration.

The second system is the 375 Accelerated Express

Again as a Mannlicher actioned rife ! But now with their WR Patented Take down system and they point it out ! They call this rifle the rifle for the 375 Accelerated Express. The advertisement in the catalog makes the reader believe it's a WR rifle when in fact it's a 1903 Mannlicher action with a WR patented take down barrel

They do not hold the patent on the 375 Accelerated Express if they did they would have listed it!

But LT holds patent on the bullet loaded in the 375 in the form of the LT Expanding Capped bullet. So again the illusion is created that they have "improved" the "375" and they give it their own name

In the ammo price list WR offers two options for the same cartridge ( 1937 catalog)

The first option is listed as the MS 9.5mm and at a higher price the 375 Accelerated Express ie a 9.5 MS loaded with the LT Capped Bullet.

Now in the same 1912 catalog they list their Farquharson actioned single shot in the 375 Cordite of H&H. They also list the 350 bore (9mm) MS which is the 9mm x 56 MS

Whew!!

quote:

Originally posted by steyrsteve:

I've never seen it mentioned before but I'll bet ole Roy Bee must have come across a 400/375, necked it down to .24 caliber, blown out the shoulder,
and "voila", had his 1968 hyper-velocity .24 cal. Case lengths are the same at 2.5"

Id say Roy came across not the 400/375 , but rather the .240H&H of the 1920s and blew it out to .240WBY

257 WB 1945
300 WB 1945
270 WB 1945
7mm WB 1947
375 WB 1947
228 WB 1947

All the 1945 belted cases were based on the 300 H&H.

The .240 WB was from 1968 and was based on the already existing WB case pattern with the double radius shoulder