The 4 basic rules remind us of this...
"Rule 4. Be sure of your target and what is beyond it."
The second clause of the sentence is there for a very good reason.
It isn't just that a bullet could hit someone and go through them and hit another person, (which does happen annually the shooting incident records for the NYPD, LAPD, and many other major police departments are on line and show these as annual occurrences, rare but they happen), but that bullets that miss, occasionally hit someone else or vehicles, homes etc. Bullets routinely penetrate exterior walls of homes.
No shooter, even the very best, can guarantee that a shot at a moving target will not pass through a limb, pass through fatty tissue, pass through a non-vital part of the body, glance off bone, etc.
These are good reasons for using jhp bullets in defensive situations. They lesson the probability of damage to what is beyond the target.
On the Underwood Ammo: I watched the vid. Not all of it though.
[I
]The concept is not new, neither are the results[/I].
This is a light weight bullet of 90 gr. +P+ moving at over 1500 fps with 21" of penetration with a bullet that remains intact, meaning the bullet does not mushroom. Up against that we have a Fed. HST jhp 124 gr. bullet moving at 1150 fps or there abouts that does expand.
No one should be surprised that the ball ammo (in this case shaped like a philips head screw driver) out penetrates the jhp. The latter is designed to expand, create a bigger hole and
limit the penetration of the bullet to a set depth. Ball ammo always out penetrates jhp ammo.
Light weight fast ball ammo (or philips head ammo) however often breaks up on impact, creating a bigger wound cavity of limited depth. It does this either because the ammo is going faster than the bullet was designed for, strikes a bone, or by intent as in the case of Glazer Safety Slugs, etc.
In the case of this Underwood ammo the intent is to not break up but to act like ball ammo. Though the philips head shape leads me to believe it could break up more easily than ball if striking a hard object. But I'm not sure of that.
A lighter than normal round like this one at, 1500 fps and 90 gr.s
always loses it's energy fast on impact. The lighter weight means it has less momentum to assist in penetration and so more energy is expended in penetration, sometimes explosively so. So it is no surprise that the first 12" or so reveal a large temporary wound cavity, possibly larger than the 124 gr. HST round.
However, also notice that the permanent wound cavity of the expanding HST round is larger.
The temporary wound channel of both bullets is significant and is damage that can't be discounted and is some times very significant. However, because the variables of the temporary wound channel are so, well variable, they can't be counted on to stop anyone or as a measure of actual damage. The permanent wound cavity can be. It is larger for the HST.
Let's look at something else here:
At about 3:30 into the vid Sturm fires the 90 gr. +P+ at 1500 into the block. At about 5:50 he fires the 124 gr. HST at 1150 into the block. Watch the movement of the blocks in slow motion.
Note the jump and wiggle. Which round hits harder? Go back and forth to convince yourself. Both the greater momentum of the HST, the bullet shape and it's expansion impart a stronger blow and the 10% gel reacts and shows that. It's only a 35 gr. difference but that and the expansion of the bullet make a difference. The expansion of the bullet slows it down and means that the
time the bullet is in the body and doing damage is longer. This is why the block of gel jumps higher and shakes more. It's why the jhp is more deadly and "hits harder".
It has more stopping power.
Look at the vid again.
https://www.youtube.com/watch?v=ClJcJ8LQFbQ
When Sturm shoots the 90 +P+ into the dead hog he aims at the shoulder blade and in line to penetrate both. But the 90 gr. pill only penetrates one shoulder blade and Sturm cannot find an exit hole. Sturm says that this is a good thing.
But is it? Not so much i think either for hunting or self defense. You want a bullet that will break bone if you can get it.
tipoc