For use inside a building...

[strambo]

CraigC, it is also accepted that a .22 will kill any deer that walks as well. Lethality is one thing. Odds of immediately incapacitating an armed threat at close quarters in low light shooting at high speed under life or death stress, is another thing entirely.

I'll take the terminal effectiveness of a good 5.56 round in the latter case over a .45cal hole all the way through the body. I don't hunt but it seems pistol hunters are in the minority with the vast majority favoring rifle rounds for deer and again, the deer aren't even shooting back.

 

[dogmush]

Strambo:

Not really a great comparison. There are a lot of regulations covering when, how, and with what you can hunt. It's not really a great indicator of actual effectiveness. In many places, for example, 5.56 is not a legal hunting round. And yet it's very pervasive in use on humans.

Also, PCC (and their SMG ancestors) have proven to be adequate man-stoppers for almost a century. All the people killed by Thompsons, Uzis, Scorpions and MP5's aren't coming back to life because tactical teams have shifted to 5.56. That's another thing people overlook. Just because a rifle round is ballistically better doesn't mean the pistol round is suddenly inadequate.

Both weapons bring advantages and disadvantages to the table. And while it makes for a boring internet argument the actual answer is both a PCC or a 5.56 carbine in trained hands is adequate to defend and/or clear a dwelling. As for which is actively better in a given situation? That will depend on many variables that are hard to predict in advance, and can change mid engagement.

So like every internet gun argument the actual answer is: "Pick an adequate weapon, train to proficiency, and it will likely serve you well.

 

[dogmush]

why spend a bunch of money on a pistol caliber carbine? If I was buying such a carbine, it would definitely shoot my pistol's rd and preferably, use my pistol's mags. I wouldn't buy such a gun myself. I've got way too much time and money invested in the AR's handling and controls to mess myself up with something that is different. Under heavy stress, you'll do what you've practiced the most. That could mean reaching for a safety lever in the "wrong" place.

I think my post number 75 covers that quite nicely.

 

[d2wing]

You pay your money and pick your poison. If I was really in need of stopping an intruder I would use a shotgun or rifle if I had one at hand. My preferred handgun is a .357 revolver. All of these are proven man stoppers. The .45 ACP is also proven. But anything you have is better than relying on 911. None of the PPC come in cartridge that is powerful enough for my tastes. Might be slightly better in a carbine over a pistol but not enough to give up the handiness of a pistol. If you think a PC Is good enough it's your money and your fight. Too many instances of people not being stopped by pistols to suit me. If you intend to shoot an attacker, you should probably shot him or them with something that has a higher percentage of stopping them. I would.

 

[strambo]

I find it interesting most of the PCC advocates in this thread are completely ignoring the actual OP and instead answering whether a PCC is a good HD choice.

I would go so far as to say a PCC is a very good HD choice when properly set up with a quality RDS, light and sling. But that isn't what he asked.

He asked (in the context of use inside a building):

why would a pistol caliber carbine not be superior to an AR in 5.56 NATO?

Because the massive increase in terminal performance of the rifle round is worth the smaller penalty of size/flash/noise/blast.

The fact that the top hostage rescue units world-wide, military and LE, have near universally abandoned SMGs for 5.56 M4s and SBRs shows that the ones who do CQB the most think it is superior.

I like the poster who took both to the range on a shot timer. Taking his results...what if we go the other way? If the PCC is 15% faster on splits and 10% faster for transitions...would it not be reasonable to assume a .22LR SBR would be at least the same percentage faster than the PCC? Why wouldn't the .22 SBR be superior to the PCC as it can be smaller and lighter still, has way less blast, recoil and muzzle flash and way less noise?

The MP5 was the undisputed king of CQB from the late 70s up through the mid-nineties. From the mid-nineties through the mid 2000's the M4 and SBR variants really came into their own and supplanted them. Pre-M4 there was the Colt Commando/CAR 15 (in small numbers) and not a lot else other than full size rifles and SMGs.

 

[Balrog]

The fact that the top hostage rescue units world-wide, military and LE, have near universally abandoned SMGs for 5.56 M4s and SBRs shows that the ones who do CQB the most think it is superior.

Do the top hostage rescue units really have the same mission and needs as the average homeowner wanting a self defense weapon in his home?

 

[strambo]

Do the top hostage rescue units really have the same mission and needs as the average homeowner wanting a self defense weapon in his home?

Does the threat level posed by armed threats in a building raided by LE or the military differ from the threat level posed by armed threats inside your home?

Do the mission based needs of LE and the military differ enough that the best small arm for individual use in a building would differ from the ideal for a home owner (in general terms) or do those needs pertain more to ancillary gear and tactics?

 

[Balrog]

Does the threat level posed by armed threats in a building raided by LE or the military differ from the threat level posed by armed threats inside your home?

Do the mission based needs of LE and the military differ enough that the best small arm for individual use in a building would differ from the ideal for a home owner (in general terms) or do those needs pertain more to ancillary gear and tactics?

I tend to think the answer to both questions is yes.
The average home break in is by 1 or 2 poorly armed poorly trained common criminals. Thats a bit different than what a Hostage Rescue Team should be prepared to encounter.

 

[strambo]

The average home break in is by 1 or 2 poorly armed poorly trained common criminals.

And this differs from the threat level on a typical SWAT raid how?

So, you are willing to deliberately choose a less-capable small arm because the odds are the deadly threat posed in a home invasion are typically "poorly armed" criminals?

I guess we just look at the same problem and threat level and come to very different conclusions. If all the following were practical and affordable, here is what I would want to protect myself and family against an armed home invasion:

5.56/6.8 SPC/300 BLK suppressed SBR,
night vision w/ IR laser,
RDS, light, sling,
body armor,
flash bangs,
at least 2 friends similarly armed.

I have as much of the above list as is practicable/affordable for me right now. I'm working on the wife as far as training goes, so far she has attended a 2 day defensive handgun course at a well-known school. Adding another well-trained person to the team is a way more massive increase in capability than the difference between .22 short and 300 Win Mag to say nothing of PCC vs. rifle caliber carbine.

I am enjoying the discussion either way, too cold and rainy to do much shooting (I guess I'm not "hard" anymore ).

 

[Balrog]

And this differs from the threat level on a typical SWAT raid how?

I didn't think we were talking about a typical SWAT raid. You had referenced "top hostage rescue units world-wide, military and LE" in Post #80.

Thats a whole lot different that the typical SWAT raid, which is the county deputies dressed in black kicking down the door of a stoner selling weed.

 

[d2wing]

I think the answer is it takes just as much fire power to stop an untrained druggy as a well trained insurgent. The point is to stop an attacker or group of them. To assume an attacker is not competent is foolish and often wrong. In fact your best defense is ability, training and determination to defend yourself. Any weapon is useless unless you can use it under pressure. I read an article about a gunfight in a small garage where 3 men fired 28 rounds and nobody had a scratch. You might not be that lucky. That said a carbine may have the advantage of being easy to point in the right direction and control.

 

[Balrog]

I think the answer is it takes just as much fire power to stop an untrained druggy as a well trained insurgent.

So if that is the case, what is the point of training?

 

[B!ngoFuelUSN]

I am not really thinking house clearing by Navy SEALS. I am thinking more along the lines of civilian home defense. The ability to engage targets beyond the effective range of a pistol caliber carbine would seem not to important to me in that situation.

Civilian home defense is the junior version of SEAL house clearing. That is, many of the same challenges, constraints and issues come to bear.
I have an AT94 (H&K MP5 style MP94 PCC) as well as a AR's and a Tavor and the PCC is definitely less loud. But that's the key word. Though not as loud, indoors it is absolutely deafening. After the first round is fired, without a suppressor or e-phones, you will not function as well for the rest of the confrontation.
But the biggest diff is what was cited earlier. The AR round, so long as it's shot out of a reasonably sized barrel (e.g. 14.5" or greater) is a far more devastating round than a pistol caliber round. More damaging, more energy and less likely to penetrate parts of the structure behind which may be friends and family.
BTW, my personal preference would be a 300 BLK with an 8-9" barrel and a brace. Here in CA, there are no SBR's allowed so the brace would have to do. But suppressors are not legal either, so e-phones would be necessary for any indoor use. However what I do not know is whether the 300 BLK bullet (shot either sub or super sonic) would have similar 'barrier safe fragmentation' as the 5.56. My suspicion is 'no' but I'd like to hear (if this is a thread hijack, please let me know and I'll open up a new one).
B

 

[Balrog]

So I guess I am crazy if I think a handgun would be considered acceptable defense by any of you guys?

 

[B!ngoFuelUSN]

The closest thing I have to a pistol caliber carbine is my old Ruger 44 Carbine chambered in 44 Magnum. The tube magazine holds 4 but I can get 5 putting one in the chamber and adding one to the magazine. There are also a few AR types laying around.

My choice for home defense is one of my traditional 45 ACP guns in 1911. I can go 7+1 or 8+1 which for my purposes should be more than adequate. I know the width of the largest room in my home and I know what is beyond my home in any direction and for me the simple 1911 is what I see as my best choice.

As to noise? I do not keep hearing protection on my night stand. If God forbid I ever need to use a gun for home defense my last concern is the bang. Never wore hearing protection hunting?

Everyone's mileage will vary as I figure you choose a home defense gun based on your specific circumstances and I doubt we all have homes with identical floor plans.

Ron

I would reconsider the hearing protection decision. Acknowledging that you may not have the opportunity to put them on, but modern electronic muffs will give you better aural acuity while walking the premises and obviously protect your ears. But in addition to preventing hearing damage (which as you note, would be an acceptable trade-off to protect family and yourself) you will instantly become less effective in the fight after the first shot if you don't wear them.
The sound of an AR round isn't loud. It's overwhelming, disorienting, and long-lasting. You may not retain your balance, you clearly will not hear the perp or the screams of your family or armed help arriving, and your overall performance is grossly hindered. It's really really bad. If the first shot is guaranteed to be your last shot, then you're only sacrificing your health. Anything more and you've got bigger problems.
B

 

[strambo]

So I guess I am crazy if I think a handgun would be considered acceptable defense by any of you guys?

Why the constant extremes? The OP didn't ask what was acceptable for HD, but rather why a PCC is not superior to a 5.56 AR.

What level of risk one is willing to accept and what risk mitigation measures are considered "acceptable" will vary widely with the operational environment, training and mindset of the individual, resources available, risk tolerance, and mostly how much they decide to even care.

A thought in the back of the mind about calling 911 is considered acceptable home defense by probably 80% of the population.

I certainly think a handgun in properly trained hands is acceptable, as is a shotgun, PCC, AR, lever action...

The more training and suitable equipment you have, the better your chances will be, but that doesn't mean your chances aren't very good even with a .22 pistol, odds are you'll be OK based on the raw statistics.

 

[Nom de Forum]

Balrog established the following weapon characteristics for comparison and asked if the comparison indicates the Pistol Caliber Carbine (PCC) is a superior weapon to the AR15 for use inside a building: The PCC is quieter, has less flash, has the same useable accuracy, is quicker for follow-up shots, and possibly shorter and consequently easier to navigate inside than the AR15. The answer to the question may vary depending on the building construction materials, who is inside the building, what is inside the building, and the size of the building. There is quite a range of difference between a typical home and an aircraft hanger.

Here are some questions and answers I have for you and everyone else:

Are the differences in noise, flash, follow-up shots, and length significantly great enough to change the outcome in what for most of us on THR what would most likely be a once in a lifetime event in our homes? My opinion is it does not.

Could the terminal ballistics of a 5.56 bullet result in incapacitation fast enough to save your life in some scenarios that the terminal ballistics of a pistol bullet would not. My opinion is it may.

Does a pistol bullet have a greater possibility than a 5.56 bullet of penetrating a wall to hit an innocent person? My opinion is that it does.

When I consider the possibility that in my home I may only have one chance to make a shot before being shot at, and may be under fire before I can make a shot, I want my shot to have better terminal ballistics than a pistol bullet. When I consider the possibility of missing shots penetrating walls and killing innocent people I want to use bullets that have great terminal ballistics and low potential for penetrating walls. I think it is wiser to accept and cope with the consequences of the greater noise, flash, slower follow-up shots, and length of an AR15 than the consequences of slower incapacitation time and greater possibility killing innocents of a PCC. If you don’t what to use an AR15, pick-up a PS90 or AR57 as a better alternative than a PCC.

So I guess I am crazy if I think a handgun would be considered acceptable defense by any of you guys?

In some situations a pistol is not just acceptable but the best choice, but a PCC is far less likely to ever be a better choice than an AR15.

 

[Balrog]

Why the constant extremes? The OP didn't ask what was acceptable for HD, but rather why a PCC is not superior to a 5.56 AR.

So if a pistol caliber carbine is inferior to a 5.56mm carbine for home defense because of terminal ballistics, is a 7.62 NATO carbine superior to the 5.56 carbine?

 

[strambo]

So if a pistol caliber carbine is inferior to a 5.56mm carbine for home defense because of terminal ballistics, is a 7.62 NATO carbine superior to the 5.56 carbine?

Because there is a point of diminishing returns at both ends of the spectrum. The .22 SBR has the fastest follow up shots and least blast, noise etc. of all but poor terminal effectiveness.

The 7.62 carbine's blast, recoil and size put it at the other extreme where those downsides begin to eclipse the increased terminal effectiveness over a good 5.56/300BLK/6.8SPC. OTOH, a strong case could be made for a light 14.5" 7.62 running 110-125g ballistic tip rounds. But then, it wouldn't be that much more than what the 300 BLK/6.8SPC can deliver.

 

[barnbwt]

"It would be convenient to leave ballistics completely out of a discussion of whether a PCC or rifle caliber carbine is more effective! But shouldn't terminal effectiveness be one of the primary considerations when choosing something to stop a deadly threat? Especially in a home where the ability to conveniently carry it is N/A?"
1) Since a portion of the discussion hinges on whether PCC's offer any advantages over a carbine (sounds like a strawman, but there are actually a good number of folks here/elsewhere who claim this), focusing on something other than that one clear-cut facet of the choice seems totally valid. More valid than claiming nothing else matters so long as the 223 is so much more powerful, or that the very power differential itself doesn't carry with it significant costs/drawbacks
2) I disagree that terminal ballistic effectiveness is a primary consideration, since any service pistol caliber is fully capable of immediately stopping a threat with an acceptably high rate of success. But even before you get to those kinds of worries, you have to consider personal preferences for various tactics/beliefs, with some folks opting for multiple accurate shots, others for very few devastating shots (certain wisdom underpinning both schools of thought, btw). The rapid double/triple-tapping folks would be wise to choose a 9mm carbine over a 223; there's simply no question your follow up shots will be faster with a less powerful round. But if you think you'll only have time for one or two shots, the rifle class rounds are more desirable, since there's a slightly greater chance an off-optimum hit will still incapacitate the threat rapidly enough.
3) Comfort of carry in a home is hardly non-applicable. You can carry a pistol with you everywhere in your home, an AR or PCC is far more cumbersome (with the latter being capable of being only slightly less cumbersome). If it ain't on you when the action starts, it doesn't matter.

"The reason ballistics aren't a deal breaker in practical HD is the same reason it isn't on the street for civilians...statistically, criminals will disengage from an armed threat more often than not."
I would also argue that hits from anything 9mm and above have proven to reliably stop threats quickly enough, which is why they stay in use for exactly that job. Guns of all calibers do carry a very real deterrent factor for a threat when they are making that split-second fight/flight calculation in their lizard-brains; but it's good to be able to make good on your end of the bet if their math is wrong. 380 and above has shown capable of that, 9mm and above has shown to reliably be capable of that.

"The FBI advises to plan on having to fight for 15 more seconds after shooting someone through the heart with a handgun."
Do they advise for rifles? I'm curious if it's any different (15 seconds isn't all that long to keep a very close eye on the threat, and you should really be continuing to fire on them if possible until they present a threat no longer, 15 seconds be damned. Regardless the bullet you're shooting)

"If you have a PCC and can use it well, it will be good for HD, but take advantage of its superior shootability to precisely place your shots (heart or mid-brain) to make up for the lower terminal effectiveness."
So you wouldn't need to hit these same areas with a rifle round to reliably stop a threat? I had no idea a 223 to the gut or shoulder (or pinkie toe, to use the cliché) would drop someone without question. Sure seems like you need to hit the upper chest or heat, regardless, with the AR's results being far more dramatic if successful. That extra "drama" can make all the difference in a borderline shot, but a hit to the head/heart means the shooter has done about 95% of what can be done, already (again, regardless of caliber). Is the additional damage done to the area you had to hit in the first place really an advantage over being able to make follow up hits faster and more accurately? I think it's just a philosophical/experiential question more than anything that can be hashed out definitively online. Which is why I take exception to the notion that ARs be universally recommended over PCCs reflexively. We don't even do that with shotguns, which are proven time and again to be terribly risky defense items (in several ways; misperceptions about needing to aim & difficulty of doing so with just a bead in the dark, very slow follow up shots & severe recoil, and the worst over penetration characteristics of any option out there (and the fact your projectiles' wound paths are narrow/linear, even if there are likely multiple hits)

"First, a pistol caliber carbine may not be quieter than a short barrel AR."
I wanna see some numbers from a legit source before I'll buy that. Sorry, but unlike the "223 BTHP rounds not penetrating as deep as buckshot" un-intuition, I don't see any physics-based reason for how a higher-pressure cartridge with far more powder/power could possibly be quieter when uncorked than a lesser alternative with the same length barrel. A PCC could sound louder to human ears if it operates in a different vocal register (pitch), but there is simply more energy being dissipated in the form of sound by a 223 than a 9mm/45acp. Again, unless I'm missing something backed by solid physics.

"There's obviously a lot of rhetoric here by folks who have never fired a PCC, indoors or out. The difference between the same cartridge fired in a rifle versus a pistol is HUGE."
Until I'd fired a 16" barreled Uzi, I wouldn't have thought it so stark, myself. But the gun practically sounded suppressed with only a set of earplugs in. ARs are painfully loud through my face (independent of muffs/plugs) unless I am squarely behind the barrel or there is no muzzle device attached. Much worse if there are any hard/flat surfaces nearby to reflect sound (which is why I don't buy the "linear comp makes it quieter" argument; maybe at the range with the bullet trap 25yds away, but not in your bedroom)

"Funny how in a hunting discussion, it is accepted that a 250gr .45 at 900fps will fully penetrate any deer that walks and kill it deader than fried chicken but when shooting people you need a rifle. Further proof that perception is everything."
Funny how a lot of folks claim hunters have no valid opinion on defense issues, too. Especially in light of the fact that hunters have as much incentive to rapidly drop their target (so it can't run/get lost, rather than so it can't keep being a threat), and also have the benefit of generally having more time to make their shot (and since it's their only shot, this generally means bringing "overkill" to bear on their target with exceedingly powerful rounds). If a hunter desiring a DRT deer, with plenty of time to line up a shot, with the tendency to use more powerful rounds than necessary in order to guarantee a rapid kill, still finds 40cal/45acp/10mm/357mag to be sufficiently effective on large-ish animal targets (smaller but tougher than us)...it stands to reason they'd do alright in the home defense capacity against garden-variety unarmed foes.

"The PCC was:
Quieter.
Had less flash.
Quicker between shots. (about 15%)
Quicker between targets. (about 10%)
More accurate on second and third shots. Well it would be better to say easier to be accurate with on follow up shots."
So pretty much what the physics of shooting a less powerful round would indicate. That leaves the remaining "figgering" to be whether or not additional power on that first shot meets or exceeds the effectiveness of delivering a second shot. Anyone here willing to make a guess at how much more effective a 223 would be at disabling than a 9mm given a torso/head shot? Is it more than double the 9mm?

"There are the obvious ballistic differences between the two, but if you think 9mm is sufficient ballistically then the PCC makes sense. Or to look at it another way: Would you rather tilt your shootability equation towards speed and accuracy, or energy/round? In reality either are probably good choices, and with training will serve you well."
At last, some even-headed advice . I, personally, see rifles as too far towards the "all eggs in one basket" approach, wherein a massive barrage is unleashed at a target. Since worst-case dictates that multiple hits are required to stop an opponent, you are now at a disadvantage than if you had a faster follow up shot. If the unsuccessful first hit is assumed to be the situation regardless the weapon chosen (and no one assumes their first hit will be the only one needed, after all), you will need at least a second, and as fast as possible. After two or more successful hits of something as powerful as 9mm or higher, the likelihood of needing additional becomes astronomically small, and simply having magazine reserve fulfills the obligation of preparedness, there.

I know "planning" a shootout is pointless/counter productive, but planning to hit the target solidly, then having to hit them solidly at least once more when the first is unsuccessful, seems pretty universal to all possible altercations.

TCB

 

[Balrog]

Because there is a point of diminishing returns at both ends of the spectrum.

Is this subjective?
Could 1 person find the blast indoors from a 5.56 unacceptable, but be able to handle a PPC ok?

Could another find the 7.62 acceptable, and opt for it over the 5.56?

 

[RustyShackelford]

SIG Sauer MPX.....

For CQB or close quarters, Id opt for the new MPX line with a SIG Sauer sound surpressor & compact barrel.
An officer or agent could use a SIG P226R/P229R/320 in .40 or 9x19mm or .357sig then have a compact MPX with a red dot & sound reducer in the same caliber. .
SIG's new carbine with a internal sound surpressor in .300aac blackout is impressive too.
The MPX with a sight & surpressor can be useful for low noise areas(hostage rescue) or drug lab raids: where muzzle flash or blast could cause problems with the chemicals(flame, fire hazard, fumes).

In my metro area, a police officer is now facing multiple felony charges for firing his M4 Bushmaster 5.56mm a reported 23 times.
The police officer was shooting the rifle at a fleeing subject in a parking structure. He hit neither the subject or the vehicle.

A SBR(short barrel rifle) or SMG(select fire) with a red dot scope & surpressor would be the way to go.
The newer .300aac blackout is now more popular with SWAT & SRT units but it's still not as common as the 5.56x45mm(5.56NATO).

 

[barnbwt]

"Also, PCC (and their SMG ancestors) have proven to be adequate man-stoppers for almost a century. All the people killed by Thompsons, Uzis, Scorpions and MP5's aren't coming back to life because tactical teams have shifted to 5.56. That's another thing people overlook. Just because a rifle round is ballistically better doesn't mean the pistol round is suddenly inadequate."
The proliferation of body armor among their opponents actually did change the calculus considerably. Until 9mm +P+ Penetrator rounds came out, those weapons could practically be mag-dumped at point blank without effect against the higher-rated protective gear. I would buy into this argument if two-bit hoods suddenly started working with high-end bullet-resistant gear, but away from active conflict zones (our border is increasingly becoming one as the cartels militarize and Federales seem to operate more lawlessly in collusion with them) these guys would be far more likely to sell their bullet-proof gear at the pawn broker, than to use it to club a gun owner over the head, steal their weapon, then come to your house and menace you/yours with impunity. 223 deformable point bullets would probably be pretty ineffective against such gear as well, btw (soft armor not so much, though)

"Could 1 person find the blast indoors from a 5.56 unacceptable, but be able to handle a PPC ok?

Could another find the 7.62 acceptable, and opt for it over the 5.56?"
Depends on how loud they yell "What?!" at this point, and how much louder they wish to yell it after a shootout . What's that line from Archer? "This is just like bubble wrap to me, at this point; but it's gotta be killin' your ears. I can do this all day..." (he's using close range gun-blast as an interrogation "aid," if memory serves )

TCB

 

[Nom de Forum]

So if a pistol caliber carbine is inferior to a 5.56mm carbine for home defense because of terminal ballistics, is a 7.62 NATO carbine superior to the 5.56 carbine?

Not really. Even with bullets designed to readily fragment on impact with building materials to reduce penetration through walls, the terminal ballistics of 7.62 NATO power have reached in my opinion an unacceptable point of diminishing returns to justify the greater bulk of a 7.62 NATO carbine. However that bulk would still be preferable to the terminal ballistics of a pistol caliber carbine. I prefer my 16" SR-15 5.56, but would prefer the terminal ballistics of a 16" SR-25 7.62 to a 9/40/45 PCC. Sure you can put frangible pistol bullets in a PCC to reduce the possibility of penetrating a wall but they have terminal ballistic qualities that most people familiar with them think are unacceptable.

 

[strambo]

Is this subjective?
Could 1 person find the blast indoors from a 5.56 unacceptable, but be able to handle a PPC ok?

Could another find the 7.62 acceptable, and opt for it over the 5.56?

Sure, on an individual basis, anything is possible and those choices are made all the time. But military, civilian and LE training experience has shown that the average shooter can run an AR very fast and accurately in a CQB environment.

As to shot placement, the poster above talked about the extreme straw man argument of how I said you better hit the heart or mid-brain with a PCC for quick stop, then asked if a gut shot with a rifle is OK? Um, no...

Handgun rounds only damage the tissue they touch. That is why you better punch a hole through something vital for rapid incapacitation. Miss the heart by 1/4" and you get lung. Big deal, even though a solid vital zone high chest (A zone-whatever) hit, a person can fight for many, many minutes become succumbing to a tension pneumothorax.

OTOH, miss the heart by 1/4" with a good rifle round and you might as well have hit it. Not only do you get tissue damage from the permanent wound channel, you also get tissue damage from the temporary stretch cavity taking tissue past its elastic limits. Same for a brain shot, a lot more tissue damage.

This won't make a poor shot with a rifle good, but it can make a less than perfect shot with a rifle an immediate stopper.

The 15 second heart shot statistic has to do with how long they can keep trying to kill you as if they weren't hit at all. It is just an approximation, I've heard it expressed as 7-30 seconds as well. The heart is just a pump, damage the pump's ability to get oxygenated blood to the brain and they will eventually lose consciousness. Damage the pump a lot more with a rifle and they will lose consciousness faster. The difference between pumping some, less, or none.

Only instant stop will be a mid-brain (3x5-ish), brain stem/medulla (golf ball) or high spine (good luck doing this deliberately) hit.