Slushee question for June-July: Velocity v. Weight

[molonlabetn]

This was a discussion at least as old as WW1...

I'd say it's older than that...

I can see the Ancient Sumerians arguing with each other over whether a big, heavy club was better than a light, fast-swinging club...

There would always be the fellow who would come knock their heads together and tell them to use whatever they had, just make sure they made contact!

Or, perhaps the Scots arguing with the Persians about whether a huge Claymore was better than a Scimitar...

[The Rabbi]

The information on this debate is all over the web. There have probably been thousands of pages on discussion boards as well as articles covering it. There is little point in reinventing the wheel.

And yes, as a matter of fact I DO know all the answers....

Next topic, in a SHTF situation would you prefer an AR or an AK?

[BimmerFreak]

And yes, as a matter of fact I DO know all the answers....

Im going to go ahead and quote this for prosperity.

[dcloudy777]

You have all the answers???

Oh it's you... I'm sorry I didn't recognize you... I trained with your unit... or read your book... or took your class... Oh yeah, NONE of those things happened because you aren't the all-knowing gunstud for which you've obviously mistaken yourself.

DanO

[Mike.357]

I don't know that I understand the physics of cartridges but I believe I prefer I larger slower travelling load. I worry about over penetration. Less than 1000 fps is what I looked for. Of course I am just speaking of self defense rounds that I assume would be deployed in close quarters.

[molonlabetn]

This is an excerpt from a similar thread on PDO, which I submitted earlier this year:

Posted Jan 4, 2007 @ 2:22:22 pm CST

Good Dialogue...

greenmountainboy wrote:

molonlabetn wrote:

greenmountainboy wrote:

Military combat and personal defense are two very different critters. I too would choose a .45 acp over a 9mm for a combat situation, but this is apples and oranges. FMJ ammo serves pretty much one purpose, and that is combat. I carry 165 +p CorBon PowRball- peace of mind feeding (despite my only FTF being cheap ball ammo in my 1911) and reliable expansion.... very reliable. Seen it with my own eyes. And seen how unreliable Hydrashocks are (230 gr anyway). No cavity to plug with heavy clothing or whatever. Even if penetration is an issue due to heavy clothing, I'll take the speed and therefore higher energy that it will deliver. The faster, lighter load will not be worse off. It HAS more energy to deliver. Period. The only time a lighter, faster load becomes inferior to a heavier bullet is WAY down range (like rifle range down range) where ballistic coefficients become more of a factor. It will then be losing speed and energy faster becoming less effective - only relevant in rifle applications. At ANY handgun range, especially personal defense range, energy delivery (a factor of total energy and bullet performance/ expansion) rules all........all besides shot placement

From what I gather from your statement, I basically agree with you in that the kinetic energy of a projectile, and it's surface area are the largest contributors in terminal effectiveness (all else being equal).

I would submit, however, that defining the total damage which a given projectile type is capable of to be proportional to its kinetic energy alone, is very one-dimensional. There is more at work, just based on physics.

In the case of terminal ballistics:

Kinetic energy (KE) defines the RATE that 'work' is performed by the projectile, on a medium. Depending on the medium, this energy is mostly dissipated in a short period of time. (i.e. Temporary hydraulic shock/cavity stretch)

Momentum (MV) must also be considered, in most cases, because it defines the potential for permanent change to the medium (i.e. displacement of a certain volume of the medium)

Light & fast projectiles generally have high KE, and low MV, which dissipate large amounts of energy very quickly... The extent of the damage it creates is entirely dependent upon the elasticity and density of the medium struck. (i.e. low elasticity materials are more likely to be penetrated without severe deformation, while high elasticity materials transmit the exerted force readily to extremities)

Heavy & slow projectiles generally have a relatively low KE, but a high MV, which will readily displace a proportional amount of the struck medium, based on it's mass. The extent of damage is far more dependent on the MV of the projectile, not on the characteristics of the medium itself.

Just ask any hunter if they would be more confident dispatching a large animal with a MagSafe 68gr .45 ACP at 2300fps (798 ft-lb KE, 22 lb-ft/s MV) or a 300gr hard-cast at 1100fps, out of a .45 Long-Colt (798 ft-lb KE, 47 lb-ft/s MV). How else could killing with a bow & arrow ever be feasible?

In choosing the correct load for a particular job, consider the mass of the target, as well as its material & physical construction. A load which disrupts a large area of tissue very violently is of no use if it fragments and dissipates its energy only a few inches past the interstice of the medium.

Federal Hydra-Shoks have mixed history, they penetrate just fine, but don't disrupt tissue as violently as others. Cor-bon, on the other-hand, consistently fragments at high velocities and rarely penetrates as much as others, though it does introduce destructive energy to the media, in a violent manner.

From what I have seen, the mid-weights in the traditional JHP spectrum, which are of bonded-jacket construction (Speer Gold-Dot, Winchester SXT, Remington Golden-Sabre, etc...) seem to fare the best when pushed to high-KE-levels.

250-300gr .44mag & .45rimmed (colt +p, casull, etc)

185-200gr .45autos & .44special

165-180gr 10mm

155-165gr .40s

125-150gr .357sig, .357mag & .38super

115-125gr 9mm & .38special

Using lighter loads than these is really only useful when used as a trade-off because of a short barrel being unable to provide sufficient velocity for the expansion of JHP under controlled circumstances (real-world variables can prevent expansion, regardless of velocity).

But, that's just my take... It makes sense to me.

molonlabetn

I think I agree with you, for the most part. I just think of momentum as more of an indicator of penetration potential. Of course way down range (with a rifle) that momentum would now translate to more energy and velocity. I just don't feel as much concern for that at point blank range where I think a personal defense handgun would be used. Of course you need adequate penetration, but you also want rapid energy delivery and don't want over penetration. Rapid energy delivery could be perceived as the opposite of penetration. Rapid energy delivery, in my mind, would result in more "stopping power" (if I dare to use such a vague and indefinable term). I want that hydrostatic shock to stop an attacker as opposed to the penetration, organ/tissue damage and lethality (as I would want hunting). Being a hunter, I understand your hunting analogy- I just see the two situations as needing a different set of ballistic characteristics to be ideal (just as I would see military combat as requiring yet another set of characteristics).

I follow your use of the term 'stopping-power', and as long as this rapid, localized energy dump takes place within effective proximity to a vital organ which will ensure the target's incapacitation, the purpose has been successfully accomplished. I agree. It is also further evidence why shot-placement truly is paramount.

On the other hand, I don't subscribe to the opinion that hunting, personal defense or warfare are exclusive of one another... At least not in terms of the most effective application of terminal ballistics for the job. Humans are animals too. A priority of a successful hunt is the swift incapacitation of the prey. In this area, Hunting and Warfare are most alike, in that lethality is desireable. On the other hand, in terms of personal defense it is just as desireable for the target to merely lose the will to fight, in this area personal defense and warfare are very similar. Ball ammo is only used in warfare because it is mandated by international law, cheap, and also because it enhances penetration of hard-targets. Even though elk don't wear body-armor, the point of shooting them is the same. We need them to be dead or taken out of action quickly. Exotic loads are legal for hunting, and body-mass dictates bullet-weight for given cartridges. Un-armored human predators don't require as much penetration as medium-sized game, but require more than varmints and pests... But it all boils down to being able to penetrate sufficiently while carrying destructive energy to vitals. Just having lots of destructive energy, or just having lots of penetration is inefficient and imbalanced... ultimately a waste of energy (at the very least )

The whole purpose of 'dum-dum' bullets, such as JHP, JSP, and such, is to dissipate the bullet's momentum in a shorter distance through greater surface area, by displacing more material per unit of distance traversed... Provided that there is sufficient kinetic energy to overcome the elasticity of the medium and initiate expansion of the projectile. Very high-velocity, light projectiles don't expand reliably either, since they usually carry more energy than can be absorbed or retained by the structure of the projectile, depending on their construction. The Sierra bullets mainly used by Cor-bon in their pistol-ammo have low structural-integrity, thus fragmenting easily. Fragmentation reduces penetration, since the mass of the projectile is lost rapidly, and momentum along with it. The newest kid-on-the-block, Barnes Solid Copper hollow-points (Cor-Bon uses them in their DPX line), have excellent structural integrity. I eagerly await more companies loading them in their ammo.

Under-penetration is far more of a problem than over-penetration, in any situation.

IMHO

molonlabetn

[molonlabetn]

The information on this debate is all over the web. There have probably been thousands of pages on discussion boards as well as articles covering it. There is little point in reinventing the wheel.

And yes, as a matter of fact I DO know all the answers....

Next topic, in a SHTF situation would you prefer an AR or an AK?

Rabbi,

I understand what you're saying, that rehashing this topic frustrates you. Please believe me when I say that the main reason for having this discussion, is because we enjoy it... it makes us think. None of us are trying to force you to agree with us, or even listen/read.

[BimmerFreak]

In a SHTF situation would you prefer an AR or an AK?

I would love to hear your opinion on this.

[dcloudy777]

But fragmentation is also an excellent wounding mechanism. Reduced momentum of the bullet fragments is somewhat offset by the greatly reduced frontal area of said fragments, which are often razor sharp and still carrying prodigious energy. Multiple fragments also open multiple wound channels, which greatly increase the odds of striking vital organs or CNS tissue. Fragmentation is the primary wounding mechanism of military 5.56mm FMJ (M855 and M193), which, armchair commandos notwithstanding, performs very well against human targets.

DanO

[molonlabetn]

But fragmentation is also an excellent wounding mechanism. Reduced momentum of the bullet fragments is somewhat offset by the greatly reduced frontal area of said fragments, which are often razor sharp and still carrying prodigious energy. Multiple fragments also open multiple wound channels, which greatly increase the odds of striking vital organs or CNS tissue. Fragmentation is the primary wounding mechanism of military 5.56mm FMJ (M855 and M193), which, armchair commandos notwithstanding, performs very well against human targets.

DanO

Indeed it does. At rifle velocities, fragmentation is one of the most efficient ways to prevent over-penetration, and enhance energy dump inside of a human-sized target... At regular handgun velocities, however, fragmentation generally cuts effective penetration in half... much like a load of bird-shot from a shotgun... causing a wide area of devastation, albeit shallow.

The problem with fragmentation, however, is that the velocity and individual structural integrity of both the projectile and the target are both critical in determining whether there will be success or failure in the effective delivery of the projectiles' energy. Too low of a velocty is usually the more common culprit in overpenetration... This is almost the opposite the problem with expansion, since JHPs can be rendered inop by non-elastic barriers (clothing, construction materials), but will otherwise expand reliably across a wider velocity range.

If I had my way, I'd carry a pistol which fired 200gr 3/4" wadcutters at 1000fps... No need to worry about expansion, since the projectile is already 'expanded' to the full diameter which most .45 JHPs achieve, and carries the same energy.

[dcloudy777]

If I had my way, I'd carry a pistol which fired 200gr 3/4" wadcutters at 1000fps... No need to worry about expansion, since the projectile is already 'expanded' to the full diameter which most .45 JHPs achieve, and carries the same energy.

In a pocket holster, no doubt, with a backup twin on your ankle

DanO

Wow, just calculated the ballistic coeffecient for a 200gr .75" WC... a really nice .045.... hope your target is close...

[The Rabbi]

I would love to hear your opinion on this.

My opinon is one thing, a rehash of the issues is another.

Personally I wouldnt have a problem with either one.

On the one side (AK) you have

-Reliability

-Few moving parts

-Little maintenance needed.

-Heavier bullet

Negatives are:

-Lack of accuracy

-Difficult balky safety.

-Larger felt recoil

On the AR side:

-Good accuracy

-More available ammo in western countries

-Less recoil

I'm sure I've left stuff out. If I were just buying one, price no object, I would take the AR since I would just personally get more enjoyment out of learning to shoot it well than I would out of the AK.

[Guest Greentimber]

All of this is meaningless.

Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement

Mindset

Tactics

Skill

Equipment

[fury2neon]

I like the 1911's and CZ's for their shot placement. The glock sights just don't seem to "fall" into place the way I wan them to. 45, 9mm are ok with me they will both do the job.

But then I prefer the 308 to 223 because 223 is all about shot placement and it has to be near perfect like with a 22 but the 308, 30-06 makes an impression even on a glancing hit.

BTW Hero Gear, you are all about small and fast in rifles why the switch in pistols? Just to stir up the conversation.... ;-)

[molonlabetn]

All of this is meaningless.

Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement Shot placement

Mindset

Tactics

Skill

Equipment

We know...

But at some point, terminal effectiveness does come into play. That is what we are discussing. To say it is 'meaningless' merely avoids the question.

[The Rabbi]

The other issue is that you dont always have control over shot placement but have to take what you can get.

A larger heavier caliber might make the difference between effective and ineffective.

[molonlabetn]

The other issue is that you dont always have control over shot placement but have to take what you can get.

A larger heavier caliber might make the difference between effective and ineffective.

Very true, especially if there are barriers which must be penetrated while still carrying some energy through them.

[Guest Terry J]

Im a light an fast person myself. Not sure if it really makes a difference as alot of people have stated i just know that growing up with my dad and reloading for years and years this is what we both prefered. Mostly because of accuracy at a distance. just my 2cents.

[dcloudy777]

Of course its meaningless... that's why all of the serious operators carry .177 air rifles into battle...

[TGO David]

Mindset

Tactics

Skill

Equipment

For me, I want the biggest damn projectile with the most kinetic energy behind it that I can carry into battle and fire with the most accuracy. But what that means to me means something else to the next guy... but as long as I'm up-range of the next guy, I really don't care.

[The Rabbi]

Very true, especially if there are barriers which must be penetrated while still carrying some energy through them.

But that seldom, if ever, happens in a private citizen type shooting.

I dont think anyone is saying caliber is unimportant. But it is a definite second to shot placement for effectiveness.

Ultimately it's a silly argument that each side can take to extemes.

So we have the "why doesnt everyone just use a .17HMR" to "You can shoot a cannonball at someone but if you miss what good is it". Balance. Balance.

[Marswolf]

Mindset

Tactics

Skill

Equipment

Capability to execute the above

[TGO David]

Capability to execute the above

For only $499 and one weekend a month...

[Guest Hornet Handler]

For only $499 and one weekend a month...

Let me guess, ditch diggers union dues and meeting.

[TGO David]

Let me guess, ditch diggers union dues and meeting.

Or you could get paid to run around with a gun, travel to exotic distant lands, meet interesting people and kill them. Hmmm. Pay to train, or train and get paid...

It's too late for me to do it all over again, but I think I'd choose the latter.