1. guns

2. Simple version-cannon
A= fuse hole
B = cannonball
Orginally stone
Soon metals for better destruction
C = gunpowder
Gunpowder appeared in Europe in 1247
Cannon introduced in 1327
Hand cannon in 1364
bore
breech

3. Matchlock Lock = ignition mechanism Stock = wooden handles
Barrel = metal tube that holds bullet and gunpowder
Lock = ignition mechanism
Light rope
Use trigger to move rope into place

4. Flintlocks—flint and steel
Flint = very hard rock
Steel = iron alloy
Additives to make it harder
Used to light fires
When flint strikes steel
Flakes off iron
Iron is hot and immediately oxidizes
Hot sparks ignite fuel (gunpowder)

5. Flintlock – put flint and steel in gun
Hammer = holds and accelerates flint
Mainspring = powers the hammer
Frizzen = holds the steel that flint strikes
Pan = holds small quantity gunpowder waiting for spark
Frizzen spring = holds cover attached to frizzen over pan to make flintlock weatherproof

6. Flintlock – mechanism to move hammer
Tumbler = holds and releases power of mainspring
Sear and sear spring = engage tumbler and release with trigger

7. Flintlock – firing 1- Half-cock hammer
2 – pour measure of gunpowder down barrel
3 – wrap lead ball in cloth or paper and ram down barrel on top of gunpowder
4 – put small amt of gunpowder in pan
5 – snap frizzen in place over pan
Half-cock position

8. Flintlock-firing part 2
6- fully cock hammer
7- pull trigger to fire gun
When you fire the gun, the flint strikes the frizzen and shaves off iron to create sparks. The hammer's blow also snaps the frizzen back to expose the gunpowder in the pan. The pan's gunpowder ignites, and it flashes through a small hole in the side of the barrel to ignite the gunpowder inside the barrel. The gun fires!
Full cock position

9. Flintlock - rifling Smooth bore = sides of barrel are smooth
Rifling = engrave groves down inside of barrel in spiral
Typical: one twist in 48 inches
Hard to load without being caught on grooves
Rifling improves accuracy
imparts spin to the bullet

10. Percussion Cap—the next step
Replace flint and steel with percussion cap
Mercuric fulminate
Hg(ONC)2
Made from mercury, nitric acid and alcohol
Shock explosive
What the percussion lock does not have is the flint and frizzen. Instead, there is a nipple that accepts the cap, and this nipple contains a tube that leads the flame from the cap down to the main charge of gunpowder in the barrel. The hammer is shaped to strike the cap on the nipple and cover it so the nipple does not get blown off.

11. Bullet design –internal ballistics
Issues
Form a seal with gun’s bore
(or gases leak instead of propel)
Engage rifling but not
Damage the bore
Distorting the bullet
Without excessive Friction

12. Bullet design—external ballistics
Shape
Spherical
orientation doesn’t matter
Forward center of mass
keeps orientation
Rotation
imparted by rifling
Stabilizes bullet
Removes (or magnifies) asymmetry

13. Bullets-materials Lead (Pb)—a classic Jacketed Lead Cheap/available
Simple to fabricate by many forms
Low melting point
Easy to work
High density (KE = ½ mv2)
soft
Make fabrication easier, but fouls grooves/rifling
Alloy with Sn or Sb to increase hardness
Jacketed Lead
Add hard metal to outside
E.g, Cu/Ni, Cu, steel
Full metal jacket
Completely encase
Soft point/hollow point
Tip not jacketed
Deforming of bullet increases stopping power

14. Let’s combine: gunpowder, ball and ignition bullet cartridge
1 -- bullet = projectile 2 -- case = holds all parts together 3 – propellant like gunpowder 4 -- the rim, which provides the extractor on the firearm a place to grip the casing to remove it from the chamber once fired 5 – primer = ignites propellant