Velocity vs. Energy

[SureShot]

Howdy all,
New shooter here, and new to the forum. Been lurking around here for a-while, but this is first thread.

Not wanting to start a caliber war. I just would like everyone’s opinion on velocity vs. energy in a self-defense round. In my way of thinking the thump at the end of the shot is what’s important. Is there anything I’m missing? I would be very interested in every one’s thoughts.

Stay safe
Paul
Proud NRA & TSRA member

[ericire12]

Put me down for energy up to a certain point.

I see it as velocity is a means to achieve energy. In other words.... if you get it going fast enough, even a 55gr projectile (5.56) can be a worthy means of self defense.

With regards to personal defense handgun ammo, I would prefer the best balance of energy as well as expansion. With some handgun rounds often times as velocity increases, the ability of the round to expand decreases. I'd rather sacrifice some energy for a round that I know will expand consistently.

There is also the factor of shootability and the debate about how much energy is enough and/or too much. I personally would take a .38 special in a snubbie rather then a .357 or even .38 + P

[TAB]

Just like when it comes to motors...


there is no replacment for displacment.


big heavy bullets for me. 

energy is useless if you can't effectivly transfer that energy,

[ellis4538]

I'll relate a story FWIW... I was shooting an IDPA match and they were using a "Pepper Popper" that was made of thicker steel than is usual (probably 1/3 thicker thus heavier).  A popper is normally calibrated to fall with a good hit from a 115 gr. 9mm.  I was shooting hard cast 200 gr. lead SWC in .45 loaded to 900 fps or so which is a stout load.  I kept hitting that D..N popper and it wouldn't go down!  Finally had to reload and double tap it to get it down!!!  WTF!  The RO wasn't impressed when I returned for a reshoot with a .38 Super shooting 147 gr. JHP loaded to between 800 and 900 FPS until the popper went down with one similar hit.  Shouldn't have gone down so easy but it did.  Go figure.

Like I said FWIW

Richard   

[Paraguy]

As you know, you also have to take what is beyond your target into consideration.  Rob did some really interesting experiments with drywall on TBD and showed some defense rounds from pistols as well as from a .223 rifle.  If you are looking for SD round I agree with most of the others, you want to trasfer as much energy as possible to the target, and if it can stay there or not destroy everything beyond it so much the better.  I am, however, not an expert, just my $.02.

[Sponsor]

[twyacht]

Ah, the philosophical quandry:

"If a bullet expands and penetrates 6" and another bullet does not expand, but penetrates 12", which one does more damage?"

Shot placement accounts for effectiveness. Bullet technology has improved, but the need for combat accuracy will always be required. Yes "thumping" with a larger caliber, has appeal, but is not always practical for concealed carry or comfort.

Everyone's mileage varies. I would love to carry my Glock 21 all the time, but I live in the swampy humidity of S. Fl. So a pocket pistol, or snub is fine, and I don't think I'm undergunned for my situation, and comfort level.

3 well placed shots with a .380, should stop/ or severly change a threat dynamic.  A bad shot or two with a 45 may not. Keep practicing, as we all do, and welcome to DRTV.

Availability [You have to have it with you.]
Reliability [It has to 'go bang.']
Penetration [It has to reach important bits.]
Placement [You have to hit important bits.]

[Timothy]

3 well placed shots with a .380, should stop/ or severly change a threat dynamic.  A bad shot or two with a 45 may not. Keep practicing, as we all do, and welcome to DRTV.

Availability [You have to have it with you.]
Reliability [It has to 'go bang.']
Penetration [It has to reach important bits.]
Placement [You have to hit important bits.]

I'll add one TW if it's OK..

Conviction [As in, are you willing to do what's neccessary?]

If not, carry a flower!

[twyacht]

I'll add one TW if it's OK..

Conviction [As in, are you willing to do what's neccessary?]

If not, carry a flower!

+100  (but it's Springtime)

[PegLeg45]

TW & Timothy, I like that, thanks.....rearranged it to make it easy to remember:

   Conviction
   Reliability
   Availability
   Placement
   Penetration
  


Also, like Eric said, you have to find balance....and the best way to do that is test, test, test for yourself. It's expensive, but necessary. Know the weapon and what ammo will work in it.

For example, I would prefer to use a .45 acp in 230 gr JHP at around 900-1000fps.....however, of all the ammo I've tested, my gun shoots the 'standard' self-defense 185 and 200 grain Cor-Bon JHP +P's more accurately and reliably in my gun than any other. I go with the 200's...they are lighter and and a little faster than what I initially wanted, but I know they work in my gun and I can hit where I want to with them (that hasn't been tested in a gun-fight).


http://www.corbon.com/

[m25operator]

Good replies here Sureshot, Velocity is part of energy, but not vice/versa, velocity and mass = energy, but it is much more complicated, mathematically, you can google " bullet energy formula " and find it, but it does not stop there, formulated data is not factual application. Diameter of the unexpanded or expanded bullet has quite the effect on stopping performance and/or applied versus wasted energy. The 7.62x39 in FMJ format is a great penetrator, but a lousy stopper, if treatment is found quickly, as has been said before, that same round square to the pump station or thought processor, will work completely, as it passes unrestricted through them. Those shots work for everything, poachers use 7.62x51 nato FMJ in Africa to one shot bull elephants, 1 behind the ear and they fall down. As has been said here, you need to reach the sweet spot, hit the sweet spot, and it is nice if it does not go through the sweet spot into someone else's sweet spot that was unintended.

I like factual data, coming from actual usage when ever possible, but a lot of that data, does not apply to the occasional 400 lb bad guy, 8 - 10" of penetration is great for most SD efforts, but this guy needs up to 18".