Terminal ballistics of rifle rounds

[marine6680]

I've yet to see a ballistician recommend it.

Thats because as civilians, we have a much wider array of options, ones that perform better.

That does not erase the fact that for a FMJ, the 55gr load was very effective, even by standards of non-FMJ.

Not as good =/= Not good at all.

Well, we've made some progress

I've never disputed that bigger/more powerful rounds are not more effective.

I am just stating that 223/556 is effective enough when good bullet selection is considered. And that it would probably be the better choice for defensive use due to to factors other than "I need that thing dead right now".


I postulated that effects like hydrostatic shock, make rounds that penetrate less than the 12-18in range most quoted, as still being viable threat stoppers. With the caveat that the rounds at least get 8-10in in gel tests.

I have read a report that during an autopsy, that bleeding in the brain was found as a result of a shot to the abdomen. The reasons for this were cited as being the force of the pressure wave caused by the bullet impact, created high pressure in the blood vessels that caused rupturing of smaller vessels and capillaries in the brain. (any other bleeding located elsewhere in the body was not mentioned, probably as the statement was meant to highlight the fact of how far away in the body the effects of the shot were felt... further mentioning of bleeding would be redundant, and likely not as important as bleeding in the brain would be)


Light weight fragmenting rounds are very good at dumping energy quickly and causing a lot of cavitation in a target. So it stands to reason that they would create a lot of hydrostatic shock as well.

Now this all hinges on hydrostatic shock being an actual thing, but many sources point to it being an actual phenomenon in bullet wounds from rifle rounds.


We also have an anecdotal account in this thread, of how light weight bullets are effective stoppers of game in the 200lb range. Results that are claimed to be from several hunts of live animals.


Given all that, I would venture that the prevailing thoughts and opinions on the suitability of lighter weight 50-55gr ballistic tipped 223 rounds, as being ill suited to effective defense use, to be incorrect.



I of course do not have means to directly test this myself. I must go by the information available, and my knowledge gleaned through study of the subject.

Right or wrong about all that... I am pretty certain that while using the handgun testing criteria methodology (gel, clothing, barriers...) as a way to evaluate rifle round effectiveness is a good way to go; using the same standards used to evaluate for actual performance and effectiveness, (12in minimum penetration, maximum weight retention...) are probably not valid. At least not fully...

 

[Llama Bob]

factors other than "I need that thing dead right now".

If I'm in the unfortunate situation where I'm shooting at someone, getting them to drop RIGHT NOW is most definitely the important thing in my world. In the case of rifles that typically also means killing them, but that's not the goal per se. That is, killing them without immediately stopping them (which is very possible) is not a very good outcome.

All factors other than achieving an immediate, complete stop really pale in comparison as far as I'm concerned. And to the extent that cartridge and bullet selection can help that happen, I'm going to take advantage of them.

 

[emcon5]

Well, we've made some progress

So you really have nothing of value to add to this discussion aside from "223 SUX 308 RULEZ!!!!"

That pretty much it?

The OP has what I think is a valid question, does the minimum penetration standard often quoted as necessary really matter if you use better bullets.

Your answer to "How can I chose effective ammo for my rifle" is "Buy a bigger gun". That is a pretty dumb answer.

If I had to use a rifle for home defense, I would much rather use something with less risk of going through 5 walls in two houses and killing the kid down the street, and I would be willing to trade some penetration for that.

All factors other than achieving an immediate, complete stop really pale in comparison as far as I'm concerned. And to the extent that cartridge and bullet selection can help that happen, I'm going to take advantage of them.

So 50BMG for everyone.

Everything is a compromise, and most folks have to make do with what they have.

 

[SHR970]

The FBI protocol is only valid for the constraints that it was developed for. That was Handgun performance vs. a variety of barriers and NO barriers to perform a desired result in a LAW ENFORCEMENT APPLICATION.

If you do not know where they dug up their magical 12" - 18" penetration requirement.. look up the cluster that was the FBI Miami shootout!

If I take a 30-06 with a 110 gr. varmit bullet @ 3400 fps and shoot someone and it only penetrates 4"... it still is going to dump 2800 ft. lb.s into the target. It will most likely STOP the attacker due to wound effects that aren't present in 1300 fps pistol ammo hits. Same reason a load of #8 bird shot from a 12 gauge may not kill an attacker but will most likely STOP the attacker from a close range hit.

 

[Llama Bob]

So 50BMG for everyone.

Nope. Once again:

What Llama Bob actually said (not what emcon5 pretended he said):

I recommend something suitable for game animals of similar size.

 

[emcon5]

So "223 SUX 308 RULEZ!!!!"

Thanks for clearing that up, and for the valuable insight to this discussion.

 

[Tucker 1371]

They were trying to fix the poor terminal performance of M193 while retaining low grade armor penetration in the M4. They more or less failed at the first goal, and succeeded at the second.

Wrong and right. Terminal performance was not a consideration when NATO adopted the M855. I say NATO because it was a NATO decision. The M193 is perfectly lethal at common combat distances. The 62gr M855 drops the velocity of the 5.56 and partially due to its construction doesn't fragment or yaw as reliably. NATO was looking strictly at penetration of a Soviet steel pot helmet at a certain range (can't remember specifically) when they adopted the M855. Terminal performance was an afterthought. M855 tends to pencil punch people at nearly any range but will sometimes fragment at close range, it's terminal performance is highly inconsistent. M193 generally flys apart when it hits soft tissue at ranges 200yds and under and has an added benefit of not over penetrating.

Don't get me wrong, I love my M1A and the SCAR-H is a cool piece of gear, but if you want someone in the military carrying a battle rifle with enough ammo to last a firefight with a plate carrier, armor, water, batteries, and maybe a metal detector and 40lbs of C4... You volunteer for it. I like the M16A4 and I love the M4, just not the ammo we are issued.

 

[Art Eatman]

Tucker, my recollection is penetration of a helmet at 600 meters.

 

[Tucker 1371]

Thanks Art! I would've guessed something shorter.

Honestly with most major powers running some type of Level III armor we need to be looking at a combination of ammunition or theatre specific ammo. M995 black tip 5.56 AP needs to be put back in the rotation.

*edit*

Getting back on track with the OP...

I'd think you would be hard pressed to find a centerfire rifle round that doesn't penetrate at least 12" of ballistic gel. I'll admit I don't have any evidence to present but I'd be fairly surpised if you could find a 5.56/.223 round that doesn't at least penetrate 12" of ballistic gel. I'd be interested to see one.

As for hydrostatic shock I would definitely think that a pressure wave of sufficient force could potentially disrupt heart function and burst small blood vessels.

 

[emcon5]

Yup, 3.5mm of mild steel out to 600 meters.

http://www.dtic.mil/ndia/2010armament/WednesdayLandmarkBPerArvidsson.pdf

 

[marine6680]

The 50-55gr tipped rounds tend to fragment quickly and... "Violently" would be an accurate description.

That fragmentation limits penetration, a the pieces have low mass, and high drag.

Here is a video that shows what these bullets do.

 

[themalicious0ne]

I think that explosively violent smaller, aka 223, rounds do have merit. Of course bigger rounds cause more damage but you can't discredit the advancement of bullet technology or the effects that they cause.

http://www.ar15.com/ammo/project/Ballistic_Gel_Experiments/BTAmmoLabsTest6/Test6.htm

Edit: it is also pretty common knowledge that the brits would put cork or aluminum in the tips of their 303 bullets because they discovered in the world wars that when their bullets tumbled, they cause far more devistating damage.

 

[Sharkbite]

You'd be hard pressed to find a centerfire rifle that does less "massive" damage. There's always the .222 I guess. Small caliber plus a projectile that doesn't expend and frequently just punches a .224 hole is not a recipe for effective terminal ballistics.

But, when you change that recipe to the same ctg USING expanding/fragmenting bullets the effect is dramatic. Hornady TAP ammo is being used to GREAT effect in 223 chambered rifles. Even out of shorter 10.5/11.5" guns the wound channel is impressive to say the least.

All the agencies i know that have used lightweight ballistic tipped bullets have had pretty much the same experience on people. Bang-Flop. Most have been shot more then one time, but thats based on the training of the shooter. We just dont fire a shot and wait to see results.

But the MASSIVE destruction to vitals in the thoracic cavity leads me to think 1 would have been just fine.

 

[emcon5]

I think that explosively violent smaller, aka 223, rounds do have merit. Of course bigger rounds cause more damage but you can't discredit the advancement of bullet technology or the effects that they cause.

http://www.ar15.com/ammo/project/Bal...est6/Test6.htm

Agreed, but that test is not really indicative of advancements in bullet technology, it is a 77 grain match bullet, where terminal performance was not a design factor.

Also, while that bullet appears to do quite well in the gel, it looks like it goes ~5 inches before it yaws and does the big damage. Compare that to the videos of the 55 Sierra Blitzking posted by marine6680 above, or the Hornady Vmax posted by me a couple days ago. The damage is more severe (especially when you consider the Vmax test was done at 200 yards), and happens much earlier. For the 77 OTM you have a ~6" of icepick would followed by ~5 inches of hamburger, for the varmint bullets the first 6 inches is hamburger.

How thick is the average tweaker home invader?

I would be interested to see a professional assessment of the various 55-60gr varmint or frangible bullets.

It does look like Honrnady is marketing something like this, their 55gr TAP (Tactical Application Police) appears to be loaded with a varmint bullet. Video here, https://www.youtube.com/watch?v=u7S3p6pe8as

The results don't look all that much different than the Vmax video I posted earlier.

 

[marine6680]

The 55gr Blitzking, having a similar intended use design as the 55gr V-max, I am guessing it has similar drywall test results... though I could not find any actual tests.

Carbon used blitzking for its defense loads at one time, from my reading.

Sme reading of older threads stated that Hornady Tap was loaded with blitzking... If true, I am guessing that is before they developed their own version in the vmax.

I had half a box of 55gr Tap that I have sitting over some 55gr blitzking. The Tap has low flash powder, so that is why it's on top. I am confident in this arrangement to be effective should it be needed.


Here is a video showing the gel test of 55gr FMJ for anyone interested.

 

[SHR970]

Why are so many of you obsessing over the 223? That's not what the ORIGINAL QUESTION was about!

Substitute 3000+ fps 17, 243, 25-06, 250-3000, 30-06, etc. Same thing different delivery system.

How about 7.62 X 39? 2100 fps FMJ? Sure over penetrates by the FBI Criteria and few will doubt the efficacy of that round. 12 Gauge Brenneke slug? How about 458 Win Mag Solid?

The FBI criteria is GARBAGE when used outside of the forgone conclusion that it was developed around. Even when used within the parameters it was developed around; it is a GUIDELINE... not GOSPEL!

 

[Sharkbite]

Why are so many of you obsessing over the 223? That's not what the ORIGINAL QUESTION was about!

Maybe you should re-read the OP. It asks about rifles used against human tgts. The caliber quoted is 556.

 

[SHR970]

Sharkbite.. read two lines down!

 

[Theohazard]

Will a bullet really break up hitting drywall?

Yes. 5.56/.223 hollow- and soft-points tend to fragment rapidly in drywall. As a result, they tend to penetrate through fewer walls than most defensive handgun or shotgun loads.

 

[themalicious0ne]

Emcon5, I agree it wasn't the intent for 77gr otm to fragment so violently and the intent was for better long range stability. I was only using it as an example that rounds besides your standard fmj can be devistating even in a small bullet. Also as stated, rounds that fragment, yaw or tumble cause more damage than simply putting an ice pick hole through. That seems to be the main reason that they are simply not discredited. That is why m855 is considered a poor performer, not ineffective, but why people prefer bigger rounds and or the rounds stated above.

I think that lot of us that do not feel undergunned using 5.56 given the correct ammunition. If I had a choice between 5.56 in m855 or a 308, I think I would choose the latter.