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 7.7x57mm Ekraysian, And About Time
Ekraysia
Posted: Oct 22 2009, 09:05 PM


68% Armaments Designer


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Joined: 9-May 09



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7.7x57mm Ekraysian - Empire of Ekraysia
Also Known As
7.7x57mm Imperial
.303 Ekraysian
.303 Imperial

Statistics



Class: Rifle Cartridge

Dimensions
Cartridge Length: 57.22mm (2.253in)
Bullet Diameter: 7.925mm (0.312in)
Neck Diameter: 8.45mm (0.333in)
Shoulder Diameter: 10.51mm (0.414in)
Base Diameter: 11.33mm (0.446in)
Rim Diameter: 12.00mm (0.472in)
Primer Diameter: 7.2mm (0.283n)

Primer: Berdan Large Rifle Only
Ballistics
- Ball
Weight: 175 Grains
Ballistic Coefficient: 0.503
MV, Fired From Sh94: 750m/s
- AP
Weight: 220 Grains
Ballistic Coefficient: 0.53
MV, Fired From Sh94: 710m/s



History


Despite being under British rule, Ekraysia had it's own national army (a composition of all the local troops raised from each state) with a large degree of independence, as had the country. This was due to political circumstances at the time, and as such it was seen as correct that the military should have it's own service rifle, and own ammunition. The .303 British cartridge, introduced in 1888 with the Lee-Metford rifle, which a few Ekraysian troops began to receive the following year, was deemed to be unsatisfactory, being of insufficiently high velocity and designed around black powder.

However, the select troops who received them, were quite happy with the .303 British ammunition in their Lee-Metford rifles at the time, but nevertheless, it was decided that supplies of .303 could not be depended on. It was suggested that the cartridge be manufactured locally, but the Arms Commission intervened with a suggestion that the cartridge be modified to an Ekraysian design and then procured for the army. This had two advantages; one, that the military could have a more effective rifle round, and two, that in conversion to this round, rechambering of rifles would be swift. As it happened, Lee-Metford deliveries were few, and issued only to the Imperial Guard, so much to the anger of British authorities, over 50,000 early Gewehr 88 Commission Rifles (for which very large amounts of money were paid), and ammunition for them, were imported in the years 1889 to 1892. Their 7.92mm ammunition (with its early faults) would be an Ekraysian secondary standard for over thirty years.

The project began in March 1889 and it was decided immediately recognised that rim-over-rim jams could be eradicated altogether by the use of a so-called 'rimless' design. It was decided that this still remarkable feature, at the time, should come as standard along with marginally heavier bullets, generally higher loadings and higher pressures and a slightly larger cartridge case overall, as well as the use of higher-power smokeless propellant. The adoption of the rimless design over the standard rimmed was due to the fact that rims could be tricky to load, especially with lesser-trained troops, into a charger clip and that, especially as certain regiments were already issuing charger clips, (otherwise known as stripper clips) as standard, and more state regiments set to follow, there lay a fundamental reliability problem. As such, even in prototype form, no fully-rimmed 7.7mm Ekraysian (then .303 Ekray/Ekraysian or .303 Imperial) was ever made.

As it happened, the British were thrown out in 1889 and Ekraysia received full independence (although concessions were established) so further supplies of .303 ammunition and rifles for it were out of the question.

The process of adoption of the cartridge started in 1890 when a few regiments started to recieve, for each soldier, a hundred rounds of ammunition and the few necessary parts for rechambering their rifles from .303 British to .303 Ekraysian. It currently sees service in the Sh1895 straight-pull rifle that replaced the Gewehr 88, marksman variants of the Sh91, and the Sh94 machine-gun, among others.

Overall, the cartridge, especially in current form, generates considerably higher pressures than comparable 7.7mm Arisaka and .303 British rounds and has a considerably higher muzzle energy. Caution should be taken in commercial rifles for stress and wear, especially in the breech.

It is compatible with bullets from the following:
  • .303 British
Ekraysian weapons chambered for the 7.7x57 are designed to chamber the round regardless of bullet length (as long as it is below the maximum) or indeed, whether there is a bullet at all, as blank ammunition merely has a solid nitrocellulose cap instead of a bullet. Today, the round in all its forms is in widespread use around the world and performs excellently in its role as a full-power, long-range rifle cartridge. Like the 7x43 that partially replaced it, the cartridge has an exceptionally flat trajectory, which can produce high accuraccy when properly employed. Later-model Ekraysian Sh1895 straight-pull, bolt-action rifles are considered among the most accurate of all the weapons in the calibre.


Propellant


The cartridge has, from the very start, been designed around and exclusively used smokeless powder propellant in a bottlenecked brass slope-sided case. The propellant, currently of Anteck manufacture and in roughly spheroid shape, is a ‘double-base’ mixture, excluding additives. The manufacture specification compound is made of the following, although figures given will vary widely;
- 53% Nitrocellulose (Propellant)
- 33% Nitroglycerin (Propellant)
- 9% Polyester Adipate (Plasticiser)
- 4% Rosin (Binder)
- 2% Ethyl Acetate (Binder)
- 1.6% N-nitrosodiphenylamine (Stabiliser)
- 1.1% Potassium Nitrate (Flash reducer)
- 1% Bismuth Antimonide (De-copperiser)
- 0.8% Graphite (Lubricant)
- 0.5% Calcium Carbonate (Acid Neutraliser)


Projectile


I. Full Metal Jacket [BALL]
IB. Full Metal Jacket - Tracer [BALL-T]
The common ball ammunition, designation Sh1889 and later the Sh42 and 77, is used as a general-purpose round. It has good stopping power and material penetration capability and is also known as ‘ball’ ammunition, it’s Ekraysian military designation, and by the acronym FMJ. It has a slightly rounded, pointed ‘spitzer’ nose and all-round jacket of Cupronickel. It often has a red tip and base to designate type although it has a distinctive appearance. The bullet is also tail-heavy. This is achieved by making the front end from a variety of aluminium alloys, which creates the effect that the bullet yaws violently after impact and is designed to tumble, forgoing international ban on hollow-point rounds but causing at greater damage than standard ball ammunition. This bullet was chosen above a ballistic-capped Jacketed Hollow Point round because tests with the 5.56mm NATO has shown that, while they have a slightly higher kill or serious wound probability, they cannot always reliably fragment at over 200 metres. This bullet has a weight of 175 grains, and has the best overall general performance in regard to trajectory, range, energy and velocity.

II. Armour-Piercing [AP]
IIB. Armour-Piercing - Tracer [AP-T]

The Sh40 AP round has a boron or tungsten carbide penetrator and surrounded by steel, jacketed in cupronickel. It is designed for use against vehicles with light armour at fairly close range, or against heavier body armour. Designed solely for penetrating armour, it weighs 220 grains and is the heaviest and longest bullet in service.
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Crookfur
Posted: Oct 22 2009, 10:02 PM


You have way too much time on your hands ...


Group: Moderators
Posts: 3,510
Member No.: 6
Joined: 10-April 07



If you want the Mk III to have been issued you might wan tto shove the dates back a few years as the SMLE MK I didn't come into servcie until 1904 and the Mk III didn't appear in servcie until 1907.

Also delaying it a few years allows you have access to spitzer bullets (1905)


--------------------
QUOTE (Lt Col Colin Mitchell)
"I have no compunction in saying that if some chap starts throwing grenades or starts using pistols, we shall kill him."
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Ekraysia
Posted: Oct 23 2009, 05:04 PM


68% Armaments Designer


Group: Members
Posts: 1,360
Member No.: 710
Joined: 9-May 09



Edited.
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Ea90
Posted: Jul 20 2011, 09:01 PM


2% Armaments Designer


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Joined: 8-June 11



The cartridge's shading (which isn't that important) and the sections Propellant and Projectile are taken from here. Did you ask Antigr's permission? (in which case I've made a complete ass of myself) or are you him? (in which case I've made even more of an ass of myself). I know he doesn't exist any more, but (unless you're him,) shouldn't you at least give him credit?
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Crookfur
Posted: Jul 20 2011, 09:22 PM


You have way too much time on your hands ...


Group: Moderators
Posts: 3,510
Member No.: 6
Joined: 10-April 07



its the same person.


--------------------
QUOTE (Lt Col Colin Mitchell)
"I have no compunction in saying that if some chap starts throwing grenades or starts using pistols, we shall kill him."
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Ekraysia
Posted: Jul 21 2011, 04:16 PM


68% Armaments Designer


Group: Members
Posts: 1,360
Member No.: 710
Joined: 9-May 09



stop tellin ppl you guise
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CuriousCatgirl
Posted: Jul 22 2011, 12:35 AM


32% Armaments Designer


Group: Members
Posts: 654
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Joined: 5-July 09



the bullet doesn't look like 0.5 bc


--------------------
QUOTE
So instead of saying that the AR "shits where it eats," we should be saying, "The AR sticks a blow dryer in its vagina, so it needs frequent re-lubing."
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Tactical Solutions
Posted: Jul 22 2011, 06:30 AM


2% Armaments Designer


Group: Members
Posts: 55
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Joined: 20-January 08



Only 21 months behind on the criticism...


--------------------
God is not on the side of the big battalions, but on the side of those who shoot best.
Voltaire
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