1Hobie said:
...Please explain how 473 pellets hitting at the same time, slightly dispersed, wouldn't have the same mass as a solid?...
Because penetration will be a function of sectional density. Sectional density is the ratio of a projectile's mass to its cross sectional area. It is a factor in determining how efficiently it can overcome resistance, and therefore how well it can penetrate. The greater the sectional density, the greater the projectile's ability to penetrate.
In measuring sectional density, we would look at each projectile individually. And a pellet of, for example, #6 shot, has a very low sectional density of about 211 grains/sq. in. with a diameter of 0.11 inch for a cross sectional area of 0.0095 square inch and a mass of about 2 grains. In contrast, a 230 grain, .45 caliber bullet has a sectional density of about 1,447 grains/sq. in.
1Hobie said:
...If I shot a solid 1 ounce load at something, it would penetrate how ever far. But, if I took that 1 ounce and spread it over a 3 inch area, would it not still have the same mass but affect a larger area with less penetration?...
Well yes, but what you want is penetration, not necessarily affecting a large area. Or, looking at it another way, trading penetration for area is counter productive. Bullets don't work in the same way as blunt force trauma.
There are four ways in which shooting someone stops him:
- psychological -- "I'm shot, it hurts, I don't want to get shot any more."
- massive blood loss depriving the muscles and brain of oxygen and thus significantly impairing their ability to function
- breaking major skeletal support structures
- damaging the central nervous system.
Depending on someone just giving up because he's been shot is iffy. Probably most fights are stopped that way, but some aren't; and there are no guarantees.
Breaking major skeletal structures can quickly impair mobility. But if the assailant has a gun, he can still shoot. And it will take a reasonably powerful round to reliably penetrate and break a large bone, like the pelvis.
Hits to the central nervous system are sure and quick, but the CNS presents a small and uncertain target. And sometimes significant penetration will be needed to reach it.
The most common and sure physiological way in which shooting someone stops him is blood loss -- depriving the brain and muscles of oxygen and nutrients, thus impairing the ability of the brain and muscles to function. Blood loss is facilitated by (1) large holes causing tissue damage; (2) getting the holes in the right places to damage major blood vessels or blood bearing organs; and (3) adequate penetration to get those holes into the blood vessels and organs which are fairly deep in the body. The problem is that blood loss takes time. People have continued to fight effectively when gravely, even mortally, wounded. So things that can speed up blood loss, more holes, bigger holes, better placed holes, etc., help.
So as a rule of thumb --
- More holes are better than fewer holes.
- Larger holes are better than smaller holes.
- Holes in the right places are better than holes in the wrong places.
- Holes that are deep enough are better than holes that aren't.
- There are no magic bullets.
The bottom line is that a lower power cartridge with a smaller caliber bullet will make smaller holes and may not be able to as reliably penetrate to where those holes need to be to be most effective.
