Ammunition Design Report

7/31/2019 Ammunition Design Report

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AAKASH SINGH

MECHANICAL ENGGMIT MANIPAL

080909024



AMMUNITION

is a generic term derived from the French languagewhich embraced all material used for war (from

the Latin munire , to provide), but which in time came to referspecifically to gunpowder and artillery

The purpose of ammunition is predominantly to project forceagainst a selected target



The components of ammunition intended forrifles and munitions may be divided intothese categories:

Explosive materials and propellants

Projectiles of all kinds

Cartridges



A cartridge, also called a round, packages the

bullet, gunpowder and primer into a single metallic

case precisely made to fit the firing chamber of a

firearm

:1. The Projectile or

2. The

3. The or “Powder”

4. The



Bullet

Cartridge

Primer

Propellant (inside cartridge)



“Bullet” refers to the projectile(s) which actually exits thebarrel of the gun when fired

Bullets vary in shape and composition and can be

optimized for minimum time of flight, minimumdispersion, maximum retained kinetic energy, minimumcross wind sensitivity, minimum ballistic drop,maximum penetration, and limiting maximum range

Most types are variations on three main shapes & threebasic compositions





Maximum penetration

Cheapest shape to

manufacture

Easily loads intochambers



Spreads or mushrooms on impact Causes additional damage to target

Inhibits penetration







- Tissue damage throughlaceration and crushing occurs along the path or "track"through the body that a projectile, or its fragments, mayproduce.

- A "permanent" cavity is caused by the path(track) of the bullet itself with crushing of tissue, whereasa "temporary" cavity is formed by radial stretching aroundthe bullet track from continued acceleration of themedium (air or tissue) in the wake of the bullet, causingthe wound cavity to be stretched outward. For projectilestraveling at low velocity the permanent and temporarycavities are nearly the same, but at high velocity and withbullet yaw the temporary cavity becomes larger

- Shock waves compress the medium andtravel ahead of the bullet, as well as to the sides, but thesewaves last only a few microseconds and do not causeprofound destruction at low velocity. At high velocity,generated shock waves can reach up to 200 atmospheresof pressure The ballistic pressure wave from distant bulletimpact can induce a concussive-like effect in humans,causing acute neurological symptoms.





Used exclusively as a practice load Minimizes penetration A wadcutter has a flat or nearly flat front

that cuts a very clean hole through the

paper target





A or is a type of all-purpose bullet commonly used in revolvers.The SWC combines features of the wadcuttertarget bullet and traditional round nosed

revolver bullets





Lead

½ Jacketed

Jacketed (Full metal jacket)



Cheap Dense

Soft

Easy to mold



A lead bullet coated with copper half wayup the exposed portion of the bullet

Used primarily for

hollow points

Copper improvesexit velocity

Lead promotes mushrooming



A (or ) is a bullet consistingof a soft core (usually made of lead) encased ina shell of harder metal, such as gilding metal,cupronickel or less commonly a steel alloy

It prevents damage to bores from steel orarmor-piercing core materials





The cartridge case seals a firing chamber inall directions except down the bore

Gases from the burning powder (deflagration)

expand the case to seal it against thechamber wall.

After the projectile leaves the barrel the

pressure drops, allowing the cartridge case tocontract slightly easing its removal from thechamber





Energy from the propellant is transferred to the bulletEnergy waves from expanding gas push bullet forward.Primer ignites propellant

Propellant burns, doesn’t explode Propellant burns from end to end and from outside to inside

Rate of gas production is keyIf produced to fast, acceleration can’t be supported andbullet slows downIf produced too slow, the bullet will leave the barrel beforethe propellant is converted to gas

Rate is dependent on:SizeShapeSurface coatings



, also known as , is amixture of sulphur, charcoal, and potassiumnitrate(saltpetre)

Gunpowder is classified as a low explosivebecause of its relatively slow decomposition rate

Powder packed behind a bullet must generate

enough pressure to force it from the muzzle athigh speed, but not enough to rupture the gunbarrel



http://en.wikipedia.org/wiki/Demolition



Velocity is equal to the square root of themass of the propellant times the “heatevolved per gram of propellant” divided bythe mass of the bullet.

V = √ 2mpQn

mb







When hit with a small

force, primer creates asmall explosion

This explosion lightspropellant creating a

large explosion (propelsbullet)



The percussion cap is a small cylinder of copperor brass with one closed end. Inside the closedend is a small amount of a shock-sensitiveexplosive material such as fulminate of mercury.

The percussion cap is placed over a hollow metal"nipple" at the rear end of the gun barrel

Pulling the trigger releases a hammer which

strikes the percussion cap and ignites theexplosive primer. The flame travels through thehollow nipple to ignite the main powder charge



Primer located in center of casing base.

.



Ammunition has primer contained in rim of ammunition casing. Rimfire ammunition limited to

low pressure loads. Rimfire cartridges notreloadable.









The inside diameter of the barrel of a firearm iscalled the caliber

The word caliber is used to differentiate bulletsaccording to their diameter and guns by the bulletsize they fire.

The final number is represented as 1/100th of theactual diameter (inches)

So if the diameter is .32 inches, it is a .32 caliber

bullet. when spoken, making it“thirty -two caliber"

. In Europe bullet calibers are expressed as mm for

example, 9mm bullet.





Determination of the nose cone geometricalshape for optimum performance

OGIVE :The profile of this shape is formed by a segment of a

circle such that the BULLET body is tangent to the curve of thenose cone at its base; and the base is on the radius of thecircle. The popularity of this shape is largely due to the easeof constructing its profile.





The ( ) of a body is a measure of its ability to overcome air resistance in flight. It isinversely proportional to the negative acceleration

BC Bullets = ballistic coefficient SD = sectional density, SD = mass of bullet in pounds or

kilograms divided by its caliber squared in inches or meters;units are lb/in2 or kg/m2.

i = form factor, i = ; (CG ~ 0.5191)

C B = Drag coefficient of the bullet C G = Drag coefficient of the G1 model bullet M = Mass of object, lb or kg d = diameter of the object, in or m



A bullet with a high BC will travel farther thanone with a low BC since it will retain its velocitybetter as it flies downrange from the muzzle, willresist the wind better

A higher BC results in a flatter trajectory which inturn reduces the effect of errors in estimating thedistance to the target

A bullet with a high BC arrives at the target fasterand with more energy than one with a low BC.



The effect of a wind on a bullet’s trajectorydepends on the speed of the wind and thedirection in which it blows

HEADWIND

TAILWIND

CROSSWIND



RIFLING : is the process of making helicalgrooves in the barrel of a gun or firearm, whichimparts a spin to a projectile around its long axis.This spin serves to gyroscopically stabilize the

projectile, improving its aerodynamic stability andaccuracy.

Inside of barrel has hills(lands) and valleys(grooves)

Lands and grooves twist downlength of gun

Grooves

Lands







TRACER ROUNDS

SHOTGUN ROUNDS

ARMOR PIERCING ROUNDS



( ) are bullets thatare built with a small pyrotechnic charge intheir base. Ignited by the burning powder, thephosphorus tail burns very brightly, making

the projectile visible to the naked eye. Thisenables the shooter to follow the bullettrajectory relative to the target in order tomake corrections to their aim.







The “bullet” part of the shotgun shell caneither be tiny pellets or “shell” that sprayout or a single “slug”.



Shot (pellets)

Wad (plastic)

Cartridge

Primer

Propellant (inside cartridge)







Armor Piercing Shell is a type of ammunitiondesigned to penetrate armor and detonate. They aregenerally used against body armor, vehicle armor,concrete, tanks and other defences, depending onthe caliber of the firearms

The most widely used armor piercing bullets in theworld are made of a HARDENED STEEL, TUNGSTEN-CARBIDE, OR DEPLETED URANIUM PENETRATORENCLOSED WITHIN A SOFTER MATERIAL, SUCH ASCOPPER OR ALUMINUM. The depleted uranium

rounds, for instance, take advantage of their high-density material, designed to retain its shape andcarry the maximum possible amount of energy asdeep as possible into the target.





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Ammunition Design Report

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