Tarea

Gun Design
There are exactly two major factors that you need to account for when designing a firearm to hold a controlled explosion in the chamber. First there is pressure, second is recoil impulse.Recoil impulse is pretty easy to deal with, and is the basis for semi automatic firearms everywhere. Manual action firearms such as bolt action, falling block, radial lock, or revolver aredesigned to keep the brass in place. There are a lot of different ways to stop the rearward movement of brass, and a couple different ways to allow it to move rearward in a controlled manner. Recoil impulsebegins when the brass begins to expand from pressure and ends after the projectile leaves the bore and the gas pressure equalizes with the ambient atmospheric pressure.

The other major factor ispressure. Pressure is what causes guns to go "kaboom" and turn from functioning machines into scrap metal in the blink of an eye. Pressure is your best friend for reliability and worst nightmare forbarrel life.

For example, a few "low pressure" rounds, the 30-30 Win and 416 Rigby. Now one is a "marginal deer round" and the other is a classic "stopper" cartridge. How can they both work at lowpressure? Surely the one that pushes more energy has to work at a higher pressure?

Not necessarily true. Pressure is what pushes the bullet down the bore, nothing more. The faster the bullet needs togo then more pressure is needed for the same bullet. Comparing the working pressure of the 416 Rigby and the 416 Barret shows that the Barret works at a higher pressure than the Rigby. 

The "watercapacity" of a cartridge has a lot to do with how much pressure it can generate by how much powder it can store. The burn rate of a powder has a lot to do with how pressure is generated. The fasterthe burn rate the quicker the pressure spikes and then drops off as the projectile travels down the bore. The slower the burn rate the slower the pressure will spike as the bullet travels down the...