Shotgun and rifle cartridges

forensic medicine

1. Shotgun and Rifle Cartridges Presented By- Nikhil Oza Batch A Roll No. 62

2. Cartridge A cartridge is usually a metallic case that packages the bullet, propellant and primer, precisely made to fit within the firing chamber of a firearm.  A cartridge without a bullet is called a blank. A cartridge that is completely inert (contains no primer and no propellant) is called a dummy.

3. Types of Cartridge Shotgun Cartridge Rifle Cartridge

4. Parts of a Cartridge Cartridge Case Propellant Projectile Wads (if present)

5. 1.Cartridge case (with Percussion cap and Primer) It is the outer shell that covers the Cartridge to keep the contents in place. I. In Shotgun The cartridge is cylindrical , 5-7cm long, base is of brass and rest is of cardboard, plastic or metal. The base is rimmed so that it properly fits into the barrel. II. In Rifled Bored Weapons The cartridge is tapering, whole of it is made from brass/steel. Size depends upon the type of weapon (rifle or revolver/pistol). Base may be rimmed, rimless or grooved.

6. ….Continued) In all weapons, after firing, the cartridge case remains in the barrel and it is to be taken out manually or is ejected out automatically. Now-a-days Caseless Cartridges are being used, in which the whole cartridge is combustible, hence no cartridge case remains for identification. Percussion Cap and Primer Percussion Cap at the base contains a small amount of sensitive detonating composition known as the Primer. The priming composition may contain- Lead Peroxide, Antimony Sulphide, Barium Nitrate, Mercury Fulminate, Potassium Chlorate, etc.

7. 2.Propellant (gun powder) It is so called as it projects the projectile forwards. It is present in between the Primer and the Projectile. 1) The classical gun powder is known as Black powder , it produces a lot of smoke and some powder is partly burnt or not burnt at all, and it is composed of- Charcoal -15% (as fuel) Sulphur- 10% (adds density) Potassium nitrate- 75% (supplies oxygen)

8. 2) Smokeless gun powder , in addition to black powder contents, it has nitrocellulose (single base), or a mixture of nitrocellulose and nitroglycerine (double base) or adding nitoguanidine along with it. (triple base). It is more effective than black powder, it is more efficiently burnt and less smoke is produced. Smokeless powder is used in all modern cartridges. It produces less blackening and tatooing of the injury when the weapon is fired from close range. 3) Semismokeless powder, has 80% black powder and 20% nitrocellulose.

9. 3. Projectile (Missile) The projectile is known as pellets/shots; Hence the name ‘Shot-gun’. Here the projectile is small, round , made of lead. The weight is around 1-1.5 ounce. Pellets may be Soft (Lead) or Hard (Lead hardened with Antimony)(Chilled Shot). A rough idea of the number of pellets in a cartridge can be had from the marking on the top wad. I. In Shotgun It is the object that is propelled out of the muzzle end of the gun.

10. The number of pellets may vary from one to a few thousand, and accordingly they are classified as- If 1: Ball cartridge If 6: LG (large game) If 8: MG (medium game) If 10: SG (small game) If 2-20: Buck Shot If 200-400: Bird Shot If 2000-3000: Dust Shot

11. Here the Projectile is single, known as bullet. The anterior part of the bullet is outside the cartridge case and the bullet is kept tight in the cartridge case by a grooving called cannelure . The weight of the bullet may range from 2-33 gms . II. In Rifled Bored Weapons

12. Mechanism When in a loaded, cocked firearm the trigger is pulled, a firing pin is released that strikes the percussion cap and detonates the sensitive components in the primer. The detonation in the primer ignites the main propellant charge and results in rapid formation of expanding hot gases at a very high pressure. The pressure of these gases build up to an optimum level and forces the projectile out of the barrel with substantial velocity. And then the fired cartridge case is manually removed or ejected automatically.

13. Dum-dum bullet : These are bullets that are designed to expand or fragment on impact. Tandem bullets- This phenomenon is observed when 2 bullets are fired in one shot, there is only one entry wound but 2 bullets are found in the body. Souvenir bullet- These are bullets that are present in the body for a long time without causing any complications. Ricochet bullet- These are bullets that change their normal path before hitting the target. Bullets-

14. Thank You….!!!