FMJ Ball For Self Defense?

[jaybet]

Having tuna breath doesn't make you a bad person.

[TWillis]

The main reason no is the over penetration of FMJ they just don't shed energy. HP's will of course pass through the human body but a significantly higher percentage of energy is imparted to the person being shot lessening the chance of someone being injured by that bullet after pass through.  Understand that the foot lbs of energy created by your cartridge is only as relevant in so much as it can effectively transfer the energy created to the medium being shot. This applies to HP's also. A good example of this the 357 mag Vs the 357 Sig both are loaded to the same velocity from near the same barrel length yet the Sig hasn't matched the stopping power of the original Mag. Why? It's been found that the soft lead nose HP's of the 357 mag opened quicker and transferred energy better than the copper jacketed bullets of the Sig.
Also on why some trainers have advocated hardball. As velocity drops HP's become less reliable and more prone to failure to open. Until the advent of powerball, critical defense and low velocity designed HP's many did carry hardball ammo in 45acp depending on weight and diameter to impart energy. This is not a good idea with higher velocity rounds like the 9mm & 40S&W.

A final point every bullet you send out into the world has a personal return address to you. If you have to shot someone to protect yourself and you kill someone behind them or paralyze or brain damage a kid your not going to have Daddy Bloomberg standing behind you to settle with the victims like those involved in the NYPD Shooting. A jury may or may not be sympathetic to the fact that your life was endangered when they see some innocent person who has been impacted by your actions.

[tombogan03884]

The main reason no is the over penetration of FMJ they just don't shed energy. HP's will of course pass through the human body but a significantly higher percentage of energy is imparted to the person being shot lessening the chance of someone being injured by that bullet after pass through.  Understand that the foot lbs of energy created by your cartridge is only as relevant in so much as it can effectively transfer the energy created to the medium being shot. This applies to HP's also. A good example of this the 357 mag Vs the 357 Sig both are loaded to the same velocity from near the same barrel length yet the Sig hasn't matched the stopping power of the original Mag. Why? It's been found that the soft lead nose HP's of the 357 mag opened quicker and transferred energy better than the copper jacketed bullets of the Sig.
Also on why some trainers have advocated hardball. As velocity drops HP's become less reliable and more prone to failure to open. Until the advent of powerball, critical defense and low velocity designed HP's many did carry hardball ammo in 45acp depending on weight and diameter to impart energy. This is not a good idea with higher velocity rounds like the 9mm & 40S&W.

A final point every bullet you send out into the world has a personal return address to you. If you have to shot someone to protect yourself and you kill someone behind them or paralyze or brain damage a kid your not going to have Daddy Bloomberg standing behind you to settle with the victims like those involved in the NYPD Shooting. A jury may or may not be sympathetic to the fact that your life was endangered when they see some innocent person who has been impacted by your actions.

That's the point I was trying to make with my earlier comment that a HP might fail to expand but FMJ never would.
TWillis said it much more clearly than I did.

[2HOW]

The FMJs I carry are 230 gr ball and 165 TMJ. I doubt the TMJ would over penetrate any more than the ball. Anyone worried about over penetration should carry frangible s. Although the new line of EFMJ bullets seem to be a good round..

[fatbaldguy]

Having tuna breath doesn't make you a bad person.

Depends if you're the tuna or not!

[Sponsor]

[tombogan03884]

The FMJs I carry are 230 gr ball and 165 TMJ. I doubt the TMJ would over penetrate any more than the ball. Anyone worried about over penetration should carry frangible s. Although the new line of EFMJ bullets seem to be a good round..

I would have left them out of the discussion for 2 reasons,
First, they are neither fish nor fowl, while they are FMJ they are designed as an expanding bullet and should be considered in the generic " HP" category since they are a perfect example of "what a difference 100 years can make".
Secondly the OP's buddy's primary reasoning is price, he's a cheap skate who if he won't send the money on regular HP's sure won't pay for EFMJ.

[2HOW]

I would have left them out of the discussion for 2 reasons,
First, they are neither fish nor fowl, while they are FMJ they are designed as an expanding bullet and should be considered in the generic " HP" category since they are a perfect example of "what a difference 100 years can make".
Secondly the OP's buddy's primary reasoning is price, he's a cheap skate who if he won't send the money on regular HP's sure won't pay for EFMJ.

LOL, yeah, Im still hoarding Black Talons, and I buy no name rounds by the bag, but they do have Gold Dot HPs for bullets. MY thoughts on rounds are like my thoughts on guns, better to have some, than none. 

[ZombieTactics]

The main reason no is the over penetration of FMJ they just don't shed energy. HP's will of course pass through the human body but a significantly higher percentage of energy is imparted to the person being shot lessening the chance of someone being injured by that bullet after pass through.  ...

Ummm ... in a word ... no. There is no "shedding" of energy or "imparting" of energy to a body. Energy is only used. In the case of FMJ, no energy is used aside from that used to penetrate. JHP ammo does not dump, shed or impart energy. It simply uses energy to penetrate and possibly expand. Expansion causes a bigger wound track, but results in - comparatively - little loss of energy as a result ... assuming we are talking about the standard kinds of duty/defense loads in common use.

Almost any bullet which over-penetrates retains enough energy to injure/wound/kill another person. The physics are such that almost any case of an FMJ over-penetrating would over-penetrate with an analogous JHP as well. The danger of over-penetration is almost (statistically speaking) mythological in comparison to the documented danger of failing to hit what you are shooting at. A flyer or miss represents a much greater chance of killing an innocent.

The original intent of HP designs was indeed an attempt to make "safer bullets". It just didn't work out that way. Any  design which potentially expands enough (with a given amount of energy) while not over-penetrating, does so with the trade off of not penetrating sufficiently when expanded. Any round which meets FBI standards for expansion/penetration does so with the trade off that it will in fact over-penetrate in a high percentage of cases. That's just how the physics work out.

At any rate, JHP designs do not expand as reliably as many think in real-world shootings. You often end up with essentially a FMJ anyway. The choice to use JHP should based upon the potential of larger wounds, not on any false notions regarding the dangers of over-penetration.

[tombogan03884]

Ummm ... in a word ... no. There is no "shedding" of energy or "imparting" of energy to a body. Energy is only used. In the case of FMJ, no energy is used aside from that used to penetrate. JHP ammo does not dump, shed or impart energy. It simply uses energy to penetrate and possibly expand. Expansion causes a bigger wound track, but results in - comparatively - little loss of energy as a result.

Almost any bullet which over-penetrates retains enough energy to injure/wound/kill another person. The physics are such that almost any case of an FMJ over-penetrating would over-penetrate with an analogous JHP as well. The danger of over-penetration is almost (statistically speaking) mythological in comparison to the documented danger of failing to hit what you are shooting at. A flyer or miss represents a much greater chance of killing an innocent.

The original intent of HP designs was indeed an attempt to make "safer bullets". It just didn't work out that way. Any  design which potentially expands enough (with a given amount of energy) while not over-penetrating, does so with the trade off of not penetrating sufficiently when expanded. Any round which meets FBI standards for expansion/penetration does so with the trade off that it will in fact over-penetrate in a high percentage of cases. That's just how the physics work out.

BS.
Larger frontal area ( what causes the "bigger wound track" in your previous paragraph ) means increased drag .
Of 2 objects at the same velocity the one with the larger diameter,IE the greater drag, will stop first .
Where does the velocity generated energy go ?
Into the medium through which the object is traveling. .

[ZombieTactics]

BS.
Larger frontal area ( what causes the "bigger wound track" in your previous paragraph ) means increased drag .
Of 2 objects at the same velocity the one with the larger diameter,IE the greater drag, will stop first .
Where does the velocity generated energy go ?
Into the medium through which the object is traveling. .

You're doing a good job of (re?)defining the terminology, but not really countering the case I made. In standard physical terms, energy is either transferred from one object to another, or is used to "do work". A good example of transfer would be a cue-ball striking the 8-ball ... energy is transferred from one ball to the other. After the transfer ... the 8-ball has energy it did not have before, which it then uses to "do work" ... i.e. moving. Once the ball has stopped moving there is no energy left in the ball.

In the case of terminal-ballistic effects, there is no "transfer" of energy from the rounds to the target, the energy is simply used to (do work) penetrate, crush and move tissue. You could argue that energy is "transferred" to the body, and that the energy is used to "do work" ... expansion and penetration, creating a wound channel. In a practical sense, terminal ballistics are never described that way, nor do any of the various formula acknowledge such an effect. 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.  But let's be honest with each other here ... whenever someone is talking about "energy dump" or "energy transfer" in the gun world, they are almost assuredly talking about some kind of magical secondary wounding effects aside from those created by the wound channel itself. My comments are/were meant to counter exactly such a notion. If there is any misunderstanding between any of us on this point, let's just have that cleared up right here.

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.

The better duty and defense rounds are designed to roughly match the IWBA/FBI standards. Any rounds meeting those standards must reliably penetrate (with or without expansion) sufficiently to reach vital structures, through large enough sections of body mass at oblique angles (i.e. "sideways"). This means that such rounds would almost certainly over-penetrate at square-on angles with enough energy left to wound/kill another individual. Designing a round which would not over-penetrate at square-on angles would mean it could not penetrate sufficiently at oblique angles. You can't have it both ways, as there is always a trade off in any systems which has to balance these kinds of performance characteristics.