Here we go again! i am not a leo, but but have close association with them on different levels, and since i AM a "gun freak" (no offense intended" they respect my opinion for the most part. here is the challenge: although i admit to the fact that the 40 cal IS a good round, there is absolutely NO advantage over the 45, furthermore, it is simply a "compromise" due to the fact that 9 is a "whimp" and 45, OR 10mm, is too much to handle, OR not politically correct (which i simply DO NOT understand AT ALL!!!) somebody convince me that there is a good reason for the existence of the 40caliber round! you can`t do it!!! if you think you can, SUPPORT IT....[heavy]

spent .40 brass makes perfect earplugs, whereas a 9 is too wimpy (small) and the .45 is simply too much and the 10 sticks out too far and makes ya look "dorky".

The .40 was developed to try to get a bigger bullet out of a 9mm size (wimp gun) frame.  Didn't work so the guns got bigger.  Where's the sense in that?

Go .45

Norm

Good so far, where are the 40 guy`s?...[pissed]

Norm, you are absolutely correct. 98% of the 40 cal handguns, are "overbored" 9mm`s...

If you are not a LEO I see no advantage to the .40.  If you are a LEO you can have about two more .40 in a full size 1911(16) than the .45 (14).  Seriously, we as civilians are mostly limited to ten rounds so why not make them ten dang big ones.

But more to answer your question my wife had a Browning Hi-power .40 and found it easy to shoot and loved it...that is till I got Kimber Compact Stainless 1911 in .45 then she said "I think I will let you sell my .40."  Which I did.  

She has since gotten a Taurus .38 Titanium revolver because she felt it would be safer for carry in her purse but that is for another thread.

Well geeeze glazer, that`s exactly WHAT this thread is about....where are all the 40 people? will you please respond so i can trace your fingerprints.....[smash]

Have shot the .40 have a 9mm will stick with the .45 acp. Buddy of mine is a LEO for a Sheriff Dept Kali. they carried a nine wanted .45's got .40's alot switched once they were ok'd  for a .45 they all went that road. Go figure!

38-40, a cowboy shooter...God bless...you hit the nail on the head.....so then does the seals and sp. forces (force recon) stay with the 45???????.....[pistol]

OK guys I'm game.  After carrying a .45 and a 9MM in service.  I can vouch that the 9MM definitely has the longer range; however, you sacrifice the take down power of the .45.  The .40 is suppossed to get the benefit of both worlds.  I recently purchased the Glock 23 and am quite pleased with my choice.  The FBI in fact adopted this pistol and same calibre for the same reasons that I mentioned.

since i run a little on the short side w/matching hands,i went w/a glock 22 instead of the 1911 fullframe.fits well in hand and i can handle the recoil better.[x]

I have a Beretta .40 and a Kimber .45 both full size and both shoot very well. I like the .40 better.

I chose the .40 because it was easier on my hands than the .45. The grip on a .45 double stack is way too fat for me, kinda like holding a Desert Eagle. I also like the option of going from a 135 grain .40 supersonic to a 180 gr. subsonic. I keep mine ready with 180's for indoor home defense use. The 135 grainers are for outside and equals or even slightly surpasses the ballistics of a .357 magnum. The 180 duplicates a 180grain .45 but with higher sectional density. The only .45 that I ever liked shooting was a SIG 220, and that only holds 7 rounds compared to the 10-12 in my .40's. I also hate the saftey thingy on the 1911 grip, it just doesn't feel solid.

HK USP's are not over bored 9mm's, they were designed around the .40 to begin with. Other calibers were added later. The USPC .40 is now my favorite pistol.

I've owned both, and like both.  I just feel safer with a .45 I'm sure either will kill a bad guy dead.  In a .40 I like bullets weights from 135gr. to 155gr. in the .45 I prefer 230gr.  Geez, black&green I thought for sure there would be at least one fanatical .40 defender, maybe that S&W behind it scared them off?

My choice is the 45.preferibly in a 1911 model.A 40 cant equal the knockdown power of the 45

I have heard that the .40 S&W was developed because lady cops couldn't handle the .45 or .357 but could handle the 9mm.  Sad thing is that with proper training I think almost anyone can be trained to fire .45.

GunLvr

You must be willing to BE convinced, but, you've stated that is not possible, so what do you want to hear?

I chose the Beretta .40 Centurion and a 96FS as it's back-up for my two .40 "Smith&Wesson" pistols.  
It turned out to be a good choice, as the Border Patrol and the Postal Police also have these (Beretta .40's) as their issue weapons, which in my case is really good because I live in an area where if it were necessary to exchange parts or ammunition, they would be close by.  Also, the local Police Dept. uses the .40, except they use Glocks.  All this made for great "Y2K" scenario justification when that was going on, yet, the fact remains that IF something were to happen, I have the ammo, and maybe, the gun commonality factor to my advantage.  In my case, here, etc.

As far as the viablity or reason for existence of the .40 S&W (Ruger calls it the .40 Auto; Beretta called it the Cal. .40, for a while), it was INTENDED to be a "compromise" in power, capacity, platform size, bullet weight, etc.

Most .45's were of the 1911 variety at the time of introduction for the .40.  That changed, but the usual capacity of 7 or 8 didn't.  Eventually, that, too, changed, but the guns were a bit large and most Law Enforcement Agencies didn't condone the cocked-n-locked 1911 platform as a duty gun, ALTHOUGH it is without a doubt the BEST COMBAT HANDGUN ever devised.  That said, the LEO isn't in combat.  And, it IS disconcerting for the average UN-gun citizen to see the hammer back on the nice officer's gun...
The 9MM Parabellum cartridge, being available in distinct levels of power, can be a wimp or not. Standard; +P; +P+; NATO; Sub-machine Gun; probably a couple more we don't generally know about or acknowledge.  Some guns can handle the hard stuff, some can't.

The .40 was pushed hard into Life after the "Miami Shootout", where the 9MM was officially crowned as a wimp.  After testing the 10MM and declaring it to be TOO much of a good thing, and too much for most available handgun platforms to handle, an equivalent "lighter load 10MM", aka, the .40 Caliber was decided upon as just right.  Short enough to fit into the existing 9MM platforms, and the springs and sometimes slides, were beefed up to accomodate the higher intensity cartridge, which threw a heavier bullet, and maintained a satisfactory capacity for LE.  Not as many bullets to "spray and pray" (I HATE THAT TERM, BTW...), yet more capacity than the .45, in some cases, double.
We ought to consider the environments in which each caliber may excel.  Depending on the situation, any one of the 9MM, .40, or .45 may be the right choice.  Either for a civilian, or LEO.  
Most of you guys already have read the gunwriters' opinions to death and beyond.  Most of you already know the story.  Most of you have made your choices for whatever reason you have conjured up.
Whether or not you are convinced of the superiority of one cartridge over another is best left to your own judgement of your circumstances.
 I have my own reasons for choosing the Beretta 96 platform as my "fun guns".  What IS important, if you must be convinced of anything, is that it works for ME, I can SUPPORT that statement, and that IS the advantage over the .45 in MY case.
IT IS WHAT IT IS. Live with it.

P.S.  NEENER-NEENER-NEENER!!!  

Sodie, while I chose the .40 for a similar reason (Glock 22 was just about max for concealed carry, .45 Glock was just too big), I have to take issue with some of your points.

You say that you have the 180gr for indoor home use?  Very illogical.  Forget the noise.  If you have to shoot someone, you'll never even hear it.  That 180gr slug is liable to end up in the neighbor's house.  The lighter bullet is a much better choice for inside home defense.

You also mention that the .40 has a higher sectional denisity (comparing 180gr to 180gr) than the .45  While this may be good when HUNTING, it is not good when shooting humans.  The .40 is more than adequate when it comes to penetration on humans.  A 180gr .45 will penetrate less than a 180gr .40  This is a good thing as we are trying to dump all the energy in the target, not leave a blood trail to track for the bar-b-que.

I really think the 165 or 180gr +P .45 is the ultimate semi auto handgun round going, but I still chose the .40 since it will be for a carry gun.  Do I worry about my .40 cal 150 gr Cor-Bon cutting the task?

[img]http://albums.photopoint.com/j/View?u=1579439&a=12205457&p=43472441[/img]

[IMG]http://albums.photopoint.com/j/View?u=1579439&a=12205457&p=43472439[/IMG]

Hell no!

I think there is a nitch for each one.

I have both the 40 and 45 but I do prefer the 45. I wanted a small handgun in addition to my 1911, so I got a Glock 27. I feel that the 40 is ideal for smaller guns like this whereas if I choose a full size gun the the 45 is my choice. Each one, if shots are well placed, is capable of stopping an attacker.

I may be wrong here, but I thought the spec-ops guys had to use ball ammo, so that is why they went with the .45 (logical). In my duty gun, I am issued 155gr JHP (.40) and have heard that this is a hot round. It was designed to replace our .357's. As far as CCW, I would rather carry a Glock 27 than a Glock 30.

Wow that sucker is almost an inch across!

I like the 180 gr. because it is well under subsonic, 950fps or so. I also have a back up 158 grain .38 for the same reason. I have some constant ringing in my ears due to the many years of Magnum shooting and heavy metal concerts. I don't want hearing aids until I'm well into my 80's.

I definately can hear/feel the difference between the two while shooting indoors. I always wear ear plugs and head gear with my .44 1365fps and I still got some ringing afterwards. The 180 grain black talons that I have in my .40's were quite mild with just ear plugs alone. The lighter rounds did have an additional "crack" that I didn't like. As for neighbors, I just hope my O.G. Black Talons do what I've seen them do to gel and phone books. They go in and stay in. [frag]

Busmaster007...what I "wanted to hear" was exactly what you said! purpose of this thread was to raise opinion/experiences, as to WHAT WORKS FOR YOU, as you stated. thank all of you for your interesting responses. I will tell you what "works" for me.....primary pd,officers model w/165hy-shk or mdl 36..depending on where etc...otherwise, i own em all shoot em all (9-40&45 i mean also 10 38 357 44magand22lr) my nephew who is leo, also has officers model, was forced to use 40 as max, ended up with a barreta and likes it more. i like it also, but i already had a glock (an offer you couldn`t refuse deal) it may be leaving soon (usp45 in sight) i will admit that i have "worked over" all the 1911`s i`ve had, but am always very happy with the results. also true for the 659 smith, that was a pos when i got it (beautiful condition outside) but now it clicks em off without a hitch. but i never feel comfortable with it, even though it`s hicap. inside the house, j frame38 outside,#4 high brass,works for me...delta as a side arm when shotgun hunting..(44broken) anybody got a 4" model 29 for sale? take care.......[:)]

Have had both but I like the 40 better.  Its smaller in size and the rounds pass the "car door" test. i.e. will pass through a car door with the window glass down.  Back when that test was done...the 45 that was used did not.  However, with ammo technology on the rise, I see some pretty hefty specs on 45+p stuff and have considerd the "compact" Glock 45 as a future acquisition.

here`s what i "like" about 40`s; one of my buddies got hold of a 4006 ( i talked him into it) we both shot a 76chevy impala scrapper, through the back window at an easy 100 yards. both bullets penetrated the front seat,(first shot shattered back glass) passed completely through dashboard and buried somewhere in engine block (couldn`t actually recover the bullets) i still love 4006 sw, not as much as before, but i know from that experience what a 40 is capable of. these were std fmj bullets, nothing special (umc`s or olins can`t recall)

Within the last year one of our local police officer fired four rounds into a stolen car that he claimed the offender was trying to back over him.  He was using 45 cal Glock with Black Talons.  One round broke out back glass and bullet lodged in the headrest.[This poor peformance bothers me]  One round entered left rear quarter panel at a 40 degree angle and bullet followed path of panel and didn't exit.  Others entered side glass and lodged in dash.  Not very impressive..but it sure cost a bundle to have car repaired...By the way he missed the offender.

This is kinda like...Ford or Chevy or Dodge?
Being an auto mechanic car gun nut? I have always held to the slogun "There is NO replacement for displacement" if you want to make horsepower!! I feel the same way about my self defense bullets. There is no replacement for extra mm, inches, etc.
165 grain Cor-Bombs will do the trick every time! There is no reason for me to carry a 9 mm or a 40 S&W for the extra capacity unless I need to "Spray the neighborhood!". That would only happen if I were set upon by a large number of assailants.
My .02 worth,
Lynn   [pistol]

.45 ACP is definitly better. Most LEO gunfights are close quarters and thus the mere mass and knockdown power of the .45 is not to be questioned in such a combat situation. With the .40  and 9mm you have to always worry about over penetration, even if you hit your target...and the the law suit afterwards. Nothing but the best .45 ACP.

I like my Ruger Mk II with CCI stingers!

First off the real reason for the .40 S&W was the 10mm was too much for even the gun it was ment for, the Bren 10. After not even 1000 rounds the Bren 10, Colt Delta, S&W's were breaking parts, wearing, etc. S&W worked up the .40 to get the FBI contract (as apposed to their loaded down 10mm load).  So you get a very versatile round.  135 gr to 185 gr loads, velocity from 1200 fps to about 850-900 fps.  It shoots flatter than the .45 and is about as good in stopping power if you choose the right load.

Every .45 acp I've ever shot did not like one load or another.  Some will not feed 185's, some will only feed ball! Browning designed the .45acp for ball loads in 1911's that is it.

But, if my life depended on putting a man down with one shot, 230 gr hydra-shocks make big holes.

There is no such thing as bullets from small arms "knocking people down" by mere kinetic energy. If this were true then the recoil of the gun would also knock down the shooter. See the video called "Deadly Weapons" where actual bullet effects on different barriers are demonstrated. The one segment showing what happens when someone wearing a level 3 vest is shot at 3 feet with a .308 will dispel the "knockdown" myth.

well i think the 9 loaded properly will penetrate car doors. when it comes to stopping power, any hunter knows that the size(weight) of the projectile and the energy it contains is what stop faction or "knock down" formula is all about.....[uzi]

Ive talked to several different instructors from different schools and i think i like the way clint smith from thunder ranch said it best
" Officially you should carry the largest caliber you can safely and efectively control.....unofficially you should practice until you can safely and effectively carry a .45"
Thats my line and ima stickin with it!

Everyone talks about ammo capacity. Who cares?
Just take another clip.
My .45 HK Tactical with three mags of different +P ammo should handle any situation.
[pistol]
If it takes more than 30 rounds, I am either a bad shot and don't deserve to live or there are 5 guys out there and one would have popped me in the back.

Imbroglio you should go back to high school and give physical science another try.  When you shoot a gun, the bullet and the firearm have an equal and opposite momentum.  According to you're logic every time I my ar15 I should experience a recoil great enough to turn my shoulder into gelatin.  Knockdown power is a function of the medium being shot, the area of the tip of the bullet, and the energy the bullet contains.  This is why a .45 is a great round: high energy, large frontal area. The bullet is able to transfer its energy to the target.

Are you guys serious!? I am sorry but none are better. They are all WEAK! If you think a bad shot with a 45 is better than a good shot with a 9mm you isa crazy!

So what do you get when you compare a 9mm, a 40, and a 45? Nothing but 3 weak handgun rounds! There is alot of people out there that need to practice more, then say that they can pee farther than the next guy because if they use it its got to be better.

The three rules of a gunfight, as I understand them, are:
1.  shot placement;
2.  shot placement; and,
3.  shot placement.

I once read that a firearms trainer said he'd rather go up against an untrained gang-banger with an UZI than a highly skilled operator with a .22.

And, when all else fails and TSHTF, I'll fall back on Clint Smith's advice when he said something to the effect of:  "A handgun is only good for fighting your way to your rifle."  And I'll give you 3 guesses what that will be....  [:)]

Sorry JacRyan, you forgot the #1 most important rule in a gunfight:

1.  Bring a gun.
2.  Shot placement.
3.  Shot placement.

When I worked at Brinks, I can think of two shootings that exemplify this.  In one case, the guard was ambushed by two men, one in a wheelchair, the other pushing.  Both men drew their guns on the guard, he was quick on the draw also, fired one shot, hitting the suspect in the forehead.  2nd assailant fled with brains and skull in his eyesight.

One shot fired, robbery ended.  While it was Brinks policy to fire for center mass, EVERYONE practiced chest tap followed by head tap, or just a well aimed head shot.  This since many robbers wore vests.  

In this case, that practice paid off.  BTW, while I never saw the pictures, the guys said that the bullet opened the back of the guy's head with a 6" vertical split, clean entry hole.

The mere energy transfered from a bullet impact does not have enough force to knock a human over. Again, this was clearly demonstrated in the video "Deadly Weapons". The host was wearing Level 3 body armor and was shot at 3 feet with a round of 7.62 Nato and did not get "knocked down". He even stood on 1 foot and when shot again still didn't fall over.

Here is a Tactical Brief about the "Myth of Energy Transfer" by the Firearms Tactical Institute.

[URL]http://www.firearmstactical.com/briefs3.htm[/URL]
"The two most important factors in stopping a bad guy are: 1) where you place your bullets, and 2) what organs your
         bullets penetrate and damage."

There are many other items of interest on their site:
[URL]http://www.firearmstactical.com/tactical.htm[/URL]

Ah, I see another of us was with the "Big B".  That was the most fun I've ever had on the job.  No kidding.  The comraderie was the best part.  
I went to the range yesterday to excercise my Beretta .40's.  I enjoyed myself thoroughly and was reassured that I made the right choice for me in the Beretta/.40 platform.  LOVE that snappy recoil. Felt good!  Nice to know it'll do well on auto glass and car doors, too.

If it weren't for the forum, I might have waited too long to get out and enjoy what I have.
Hey, guys, don't spend your time wasting air; take whatcha got and go get better with it!  If we were all at the same place at the same time in a bad situation, we wouldn't be concerned with what the other guy had, we'd wanna know if he could shoot it.
Thanks for the prompting.  Now, go have some FUN.

Ha ha ha!!!!!!  Imbroglio you're a riot, "The host was wearing Level 3 body armor and was shot at 3 feet with a round of 7.62 Nato and did not get "knocked down". He even stood on 1 foot and when shot again still didn't fall over."   If you believe this I pity you, and you're fireamstactical stuff is bogus, no research provided, all pulled out of someones butt.  Sure LEOs walk away from getting shot in vest, but a lot more get nasty bruising, broken ribs, and internal bleeding, from impact.  And comparing knife wounds to gunshots wounds is bogus (ask any hunter who uses both firearms and bows).  If anyone actually got shot from 3 feet away wearing any level III, plated, heavy tactical armor, is going to end up dead from impact.  Imbroglio if there was no such thing as knock down power why would cops need anything other than .22lr.

All i want to know is, how did this thread get from a handgun subject to a rifle subject? I think half of you guys are sitting back, half informed wanna-be`s, that have some kind of personal problem, probably sexual related, that causes you to go off on a tangent,about what you wish you could do, about what you wish you WANT to do, and the only thing you can REALLY do, is ARGUE about it with whoever is willing, most likely because the lake is froze and you can`t go fishin` right now!....WELL! LET`S HAVE IT!..some of you guys never even shot a 45!!!![smash]...[pyro]

It is obvious you only want to stick to your own ignorant beliefs. I see none of your research except what you have pulled out of YOUR butt. It is obvious you only read the first paragraph of the article.

Here is another article for you to ignore:

Newgard, Ken, M.D.: "The Physiological Effects of Handgun Bullets: The Mechanisms of Wounding and Incapacitation."  Wound
         Ballistics Review, 1(3): 12-17; 1992.

              This article examines the physiological mechanisms of the human body to provide a medical answer to the question: How many
              times is it necessary to shoot an assailant before he is incapacitated?

              Newgard reviews the physiological mechanisms of gunshot wound trauma incapacitation:

                   "The only method of reliably stopping a human with a handgun is to decrease the functioning capability of the
                   central nervous system (CNS) and specifically, the brain and cervical spinal cord. There are two ways to accomplish
                   this goal: 1) direct trauma to the CNS tissue resulting in tissue destruction and 2) lack of oxygen to the brain
                   caused by bleeding and loss of blood pressure."

              Newgard discusses the body's blood loss sensory and compensatory mechanisms (venous constriction, increased cardiac output
              and vascular fluid transfer), and the degree in which these mechanisms respond to, and compensate for, hemorrhagic shock. He
              reviews clinical tests of human tolerance for blood loss, which "demonstrate that adequate blood pressure can be maintained with
              minimal symptoms until a 20% blood deficit was reached." Newgard provides the following example:

                   "For an average 70 kg (155 lb.)* male the cardiac output will be 5.5 liters (~1.4 gallons) per minute. His blood
                   volume will be 60 ml per kg (0.92 fl. oz. per lb.) or 4200 ml (~1.1 gallons). Assuming his cardiac output can double
                   under stress (as his heart beats faster and with greater force). his aortic blood flow can reach 11 liters (~2.8 gallons)
                   per minute. If one assumes a wound that totally severs the thoracic aorta, then it would take 4.6 seconds to lose
                   20% of his blood volume from one point of injury. This is the minimum time in which a person could lose 20% of his
                   blood volume.... This analysis does not account for oxygen contained in the blood already perfusing the brain, that
                   will keep the brain functioning for an even longer period of time.

                   "Most wounds will not bleed at this rate because: 1) bullets usually do not transect (completely sever) blood
                   vessels, 2) as blood pressure falls, the bleeding slows, 3) surrounding tissue acts as a barrier to blood loss, 4) the
                   bullet may only penetrate smaller blood vessels, 5) bullets can disrupt tissue without hitting any major blood
                   vessels resulting in a slow ooze rather than rapid bleeding, and 6) the above mentioned compensatory
                   mechanisms."

              Newgard investigates the survival times of persons who received fatal gunshot wounds to determine if the person who was shot
              had enough time to shoot back.

(continued)
He concludes:

                   "Instantaneous incapacitation is not possible with non central nervous system wounds and does not always occur
                   with central nervous system wounds. The intrinsic physiologic compensatory mechanisms of humans makes it
                   difficult to inhibit a determined, aggressive person's activities until he has lost enough blood to cause hemorrhagic
                   shock. The body's compensatory mechanisms designed to save a person's life after sustaining a bleeding wound,
                   allow a person to continue to be a threat after receiving an eventually fatal wound, thus necessitating more rounds
                   being fired in order to incapacitate or stop the assailant."

Hey pcf, is the Firearms Training Unit of the FBI in Quantico pulling this out of their butt too?

Handgun Wounding Factors and Effectiveness

Special Agent UREY W. PATRICK

         FIREARMS TRAINING UNIT
         FBI ACADEMY
         QUANTICO, VIRGINIA

         July 14, 1989


[URL]http://www.firearmstactical.com/hwfe.htm[/URL]

"Psychological factors such as energy deposit, momentum transfer, size of temporary cavity or calculations such as the RII are
         irrelevant or erroneous. The impact of the bullet upon the body is no more than the recoil of the weapon. The ratio of bullet mass
         to target mass is too extreme.

         The often referred to "knock-down power" implies the ability of a bullet to move its target. This is nothing more than momentum
         of the bullet. It is the transfer of momentum that will cause a target to move in response to the blow received. "Isaac Newton
         proved this to be the case mathematically in the 17th Century, and Benjamin Robins verified it experimentally through the
         invention and use of the ballistic pendulum to determine muzzle velocity by measurement of the pendulum motion."29

         Goddard amply proves the fallacy of "knock-down power" by calculating the heights (and resultant velocities) from which a one
         pound weight and a ten pound weight must be dropped to equal the momentum of 9mm and .45ACP projectiles at muzzle
         velocities, respectively. The results are revealing. In order to equal the impact of a 9mm bullet at its muzzle velocity, a one pound
         weight must be dropped from a height of 5.96 feet, achieving a velocity of 19.6 fps. To equal the impact of a .45ACP bullet, the
         one pound weight needs a velocity of 27.1 fps and must be dropped from a height of 11.4 feet. A ten pound weight equals the
         impact of a 9mm bullet when dropped from a height of 0.72 inches (velocity attained is 1.96 fps), and equals the impact of a .45
         when dropped from 1.37 inches (achieving a velocity of 2.71 fps).30

         [B]A bullet simply cannot knock a man down.[/B] If it had the energy to do so, then equal energy would be applied against the shooter
         and he too would be knocked down. This is simple physics, and has been known for hundreds of years.31 The amount of energy
         deposited in the body by a bullet is approximately equivalent to being hit with a baseball.32 Tissue damage is the only physical
         link to incapacitation within the desired time frame, i.e., instantaneously."

Okay, some people have obviously been watching waaaaayyyyyy too much TV.  People, handgun bullets do NOT knock human beings down.  "Knockdown power" with a handgun is a joke.  You have to hit the central nervous system, the skeletal system, or let out enough blood to depressurize the circulatory system in order to stop someone with a handgun bullet.  Or, be lucky enough to shoot someone who just gives up.

PCF, you're an idiot.  I've seen the video, and the guy does really get shot with a .308 AP round from an FN FAL at close range.  He's wearing a rifle-resistant vest with ceramic plates designed to stop rifle bullets.  You can see where he gets hit, but he's not hurt at all.  The vest has padding to prevent injury through backface deformation (look it up). Even a .308 doesn't have enough energy to 'knock someone down', it has to stop through the same mechanisms described above, and elaborated on through Imbroglio's post.  Imbroglio has done his homework, all you seem to have done is watched too many movies.  You're assuming it is simply the momentum of the bullet that does the damage, but that's just plain wrong.  Your shoulder doesn't turn into gelatin when you shoot your AR because there's far more than simple momentum doing the damage to the target.  The guy who took the .308 on the vest will no more die from just the impact than the shooter will from the recoil on his shoulder.  Study up on fluid dynamics and bullet performance in a fluid medium- you'll find it very enlightening.  I doubt you'll see anything about it on 'Miami Vice', however.  

If anyone really wants to know about this subject, get Evan Marshall and Ed Sanow's book "Street Stoppers".  For those of you who aren't familiar with it, they gathered data on how various rounds performed in actual gunfights.  The 115-grain +P+ 9mm loads outperform many .45 loads, and the best .40 loads beat them both.  The mid-weight (155 grain) .40 loads have more energy than almost all of the .45 loads, and they are NOT more likely to over-penetrate.  The lighter, faster .40 loads actually penetrate about the same as the .45's.  Their data is by no means conclusive, but it does indicate strong trends.

I love my 1911, but I hate to tell you, guys, it's not a bloody ray gun.  The .40 can deliver significantly more energy and, because of its smaller cross-section, much better penetration through barriers than a .45.  With modern hollowpoints this does not translate into over-penetration in humans because the bullet expands early and dumps all of its energy into the target, most of it in the first 6-9 inches.  Many of the .45 loads expand slower, dump their energy too late and waste it by over-penetrating.  There's nothing wrong with a .45- with the right load, it's an excellent self-defense round.  As is the 9mm, with the right load.  Pick a gun you like, research ammo and pick a good load, then practice your butt off so you can get good hits.  

And I have to say it again, just to make sure I make the point:  pcf, you really are an uninformed idiot.

Sparky, so then my 10, w/180gr hyshks, is probably the most effective, overall???

100 watt bulb gives off the energy of a triton quik-shok .45acp every 36 seconds, my hairdryer gives off that same amount in probably 3.6 seconds, a shotglass full of this 7up I'm drinking right now has more energy than that. this is fun...well not really but I'm bored almost finished off my battle-pack of crisp and clean and no caffeine

Black&green:  I believe the Federal 180-grain Hydra-shok is a medium-velocity 10mm load, which makes it just a little warmer than a 180-grain .40 S&W load.  The heavier .40 loads are not as good as the light, fast loads.  The first generation of .40 loads were all 180-grainers at about 950 feet per second, and they did fairly well.  The later generation of 165, 155, and 135-grain loads at higher velocities seem to be doing much better.  They dump their energy faster, which seems to correlate to quicker neutralization of human threats.

If the recoil doesn't bother you, consider switching over to Cor-bon's 150-grain full-power load or even the Winchester 175-grain Silvertip.  The ballistics are better than any medium-velocity load, and they tend to be more accurate because there is less air space in the case, so you get more consistent powder burn.  The 180-grain Hydra-shok MV load is fine, though.  It's not the best load available for the 10mm, but it should give you good service.  If you don't like the recoil of the full-power 10, you might want to consider switching to a .40.  There are lots more loads available in .40 than in 10mm medium velocity, not to mention more models of concealable pistols.  But, if you have a good, reliable 10 that shoots those Hydra-shoks well and you feel good carrying it, leave it be.  There are certainly  worse combinations out there!

This is from the Georgia Arms website.  The only .40 faster than the fastest .45 is the 155gr, which is 30 gr lighter.  Where the idea that the .40 hits as hard or harder than the .45 is beyond me.  I don't believe that the facts bear that out.  I will stick with the .45.  I also have some 9mm's for the following reason.  If the SHTF, and I am not one who worries about it, 9mm and .45 will me readily available, whereas .40 and 10mm might become scarce.

CAL                 FPS

40 S&W 155gr JHP+P 1200
40 S&W 180gr JHP+P 1050
40 S&W 165gr JPH+P 1100  

45 ACP 185gr JHP+P 1100
45 ACP 230gr JHP+P 850

From the aforementioned "Street Stoppers" book:

Federal .45 ACP 230-grain Hydra-shok (highest rated .45 load in the study):  850 fps/369 foot pounds of energy, 12.0 inches penetration in 10% gelatin.  Average stretch cavity 28.4 cubic inches.  Average crush cavity 5.73 cubic inches.

Winchester .40 S&W 155-grain Silvertip:  1205 fps/500 foot pounds of energy, 13.5 inches penetration in 10% gelatin.  Average stretch cavity 46.8 inches.  Average crush cavity 5.2 cubic inches.

So you can see the .40 load has considerably more energy, has a permanent crush cavity darn near as large as the .45 and a stretch cavity considerably larger.  Bullet weight and velocity are only two factors to consider.  Contrary to what a lot of die-hard .45 fans believe, the evidence seems to indicate that the stretch cavity IS relevant to the round's ability to stop threats.

My service weapon is a .45, but I also carry a Glock 27 in .40 for backup. In both cases the ammunition is Federal Hydrashock (not my choice) There are obviously many opinions on this subject. The Ohio State Highway Patrol carries the .40. Many of the municipal depts carry the .45. I like the .40 because it does allow more rounds to be carried. On the other hand the .45 is tried and proven. I would not carry a 9mm unless I had no other choice. My choice would be the .357 SIG if I could carry whatever I wanted.