FMJ Ball For Self Defense?

[jaybet]

I'm just a guitar player, but if a cue ball transfers energy to another ball by hitting it, why doesn't a bullet transfer energy to flesh and bone when it hits?  Impact transfers energy. Not ALL the energy in a round or it would stop dead (pardon the pun).

[ZombieTactics]

I'm just a guitar player, but if a cue ball transfers energy to another ball by hitting it, why doesn't a bullet transfer energy to flesh and bone when it hits?  Impact transfers energy. Not ALL the energy in a round or it would stop dead (pardon the pun).

It's probably splitting hairs ... like noting that Newtonian physics is actually wrong, but still using it because the equations for relativity are frikkn' HARD, and Newton's stuff is as accurate as you need it to be for what you are describing or calculating.

The point is that - other than expansion and penetration - there isn't anything else of note happening.

[Solus]

It's probably splitting hairs ... like noting that Newtonian physics is actually wrong, but still using it because the equations for relativity are frikkn' HARD, and Newton's stuff is as accurate as you need it to be for what you are describing or calculating.

The point is that - other than expansion and penetration - there isn't anything else of note happening.

No heat generated?  I'd guess that really isn't of note...but it will be happening.  There will also be energy used to create the temporary wound channel, which I guess can be thought of as a function of penetration and expansion...

[PegLeg45]

Regarding expansion vs. penetration ... my comments stand. The ideal round would be one which expanded completely and reliable in all or most cases, penetrating enough to pop out the other side and plop neatly on the ground, and doing so at that point with insufficient energy to further wound or kill. A round which does not adequately penetrate does not "dump" some kind of energy to the target ... it simply runs out of energy to do any more work. Inadequate penetration is a larger problem than lack -of-expansion ... a fully expanded round which does not penetrate to vital structures is not an effective round.

The problem is that there is no way to design round which will reliably penetrate to vital structures in some cases which will not over-penetrate in others. It's not as though we have a static model for our design, with only one target type and composition, and always being shot at a single distance at a particular angle.

I have made similarly-based statements in past conversations at my range.

Hard to have a "one size fits all" SD round.
Ammo makers are basically trying to provide what will work in "most" cases.

[ZombieTactics]

No heat generated?  I'd guess that really isn't of note...but it will be happening.  ...

I mentioned heat in an earlier post:

...  If you wanted to get really picky, any residual energy is expressed (with handgun rounds) as slight elevations of temperature, but no actual wounding effects.  ...

[Sponsor]

[jaybet]

I don't know...the energy statistics on rounds... a thump on your kidney or liver and then a tearing wound right through the organ?  The natural bruising from the transferred impact energy coupled with broken blood vessels...that's additional damage.

I"m just not buying the minimalist approach..there's so much data out there that a round entering the body transfers energy, and the transfer occurs as an IMPACT- damaging, PLUS a gaping wound if your round is large enough and expands enough? Sounds like there are factors in that equation you might want to enhance. It's not "all the same".

[tombogan03884]

You're right Jay, if it were "all the same" then ammo companies would not have spent the last 110+ years on research and development of soft point and hollow point bullets.

[ZombieTactics]

I don't see where anyone said anything about "they're all the same". Did I miss it? Seems like a strawman to me.

[PegLeg45]

Things (as usual,   ) kinda got tangentially sidetracked from the original topic.....which was FMJ for self defense.


IMHO, the bottom line on that is FMJ is better than nothing at all.....and pretty anything else is better than FMJ.
Heck, I think a wadcutter is better than FMJ...but that's just me.


Laying all the technical and physics aside, and like I alluded to earlier, there is no 'magic bullet' for SD. They might have a few 'one-size-fits-most-cases' rounds on the market..... but nothing is going to work 100% of the time in every situation.... just too many variables...... But every ammo maker out there, as Tom was getting at, is always trying to come up with the next better thing.

Like Zombie said, the perfect SD round would open up fast, to maximum diameter, penetrate completely through, while destroying as much tissue as possible and stopping in the first layer of clothing on the opposite side......
Probably never happen.
Maybe some day they will get close.....but until then, we have debates like this, which is good, and continue to carry what we feel is the best round we can carry.

[kmitch200]

The "transfer of energy" would be the equivelent of getting high fived by a 10 yr old. About what you feel when you shoot a handgun round.
The main difference being that the energy hopefully is used tearing up vital stuff if you hit where you intended.

I use JHPs because I want that energy to expend heat, shock, or whatever in expanding and hopefully not exiting. If it does and hits someone innocent, (after using a bunch of that energy in whatever form is the current parlance), it may not have enough energy to penetrate to be fatal.
I will also hopefully have an attorney that is well prepared to explain how JHPs are used by the police because they are safer.

That's a lot of hoping which is a product of using a gun for SD.