Terminal ballistics of rifle rounds

M

marine6680

New member
I was thinking about rifle round terminal ballistics after watching a few gel tests.


In the tests, and pretty much every gel test of rifle ammo that I seen that had a self defense slant to it... All used the FBI pistol round testing to discuss effectiveness of the round. With the 12-18 inches of penetration being considered key.


Now, for pistol rounds, it has always been stated that due to the fact that they only really do effective damage through direct contact destruction of tissues... That was the reason for the minimum penetration of 12 inches. You needed the penetration to reach vital areas, as there is no secondary wounding present in pistol terminal effects.


People doing gel tests on rifle rounds, and people on forums also use the 12-18 inch range to determine the worth of rifle rounds for defensive use.

But with rifle rounds we also talk about things like cavitation and hydrostatic shock... Secondary wounding methods present in rifle rounds.


To me it seems that if we hold those two effects as relevant to the round's performance, then maybe the 12 inch minimum is not as important with a rifle round.

The 18" maximum might be a good thing to consider, for the same reasons as it is with pistol rounds.


So am I off base thinking that a round that does not meet the 12" minimum could still be very effective in defense use?

I'm not saying a round that only penetrates 5-6 inches is good, but maybe one that can do 8-10 inches, especially if it dumps a lot of energy and causes large wound paths. These do tend to be 223/556 rounds in the 50-55gr range, hollow point or ballistic tip type.

It may even be worth considering due to the much lowered chance of over penetration, definitely not of any fragments that would continue to pose mortal wounding capabilities.

I have noticed that rounds in this range of penetration, when tested for barrier penetration, tend to break up quickly when passing through typical interior walls, to the point of being several small fragments by the time it passes through one wall.


So are we using the FBI pistol standard of 12-18 inches simply because we have no comparable standard for rifle rounds, or because it is actually important/relevant?
 
If it's just an individual assailant in light clothing at 10 feet even 12" is unnecessary. I guess the FBI is allowing for a car door or other light cover.
We all know the story of the 45 acp - a highly-motivated attacker, possibly fortified with a locally produced stimulant, brandishing an edged weapon which he definitely knows how to use. Death is immaterial - he needs to be put down, the harder the better. I'm not sure about 223. Will a bullet really break up hitting drywall?
 
My experience with various critters with various center-fire rifles is that worrying about "data" is not worth the effort. A hit in the heart/lung area = dead.
 
With a rifle for non-dangerous game or humans, I want to know four things:
1) Is it of suitable caliber for the animal (6mm+ for deer and humans, .277+ for elk, large black bear and moose)?
2) Does it expand?
3) Does it hold together?
4) Does it have enough sectional density/penetration to produce an exit wound at any reasonable shot angle?

And then the obvious follow-on is out to what range will 2) and 4) still be true?

If those three requirements are met, I'm 100% happy with the ammo. Rifles have sufficient energy at short ranges that I expect and want the bullet to exit. Good exit wounds bleed big time.

The FBI handgun protocol doesn't have a thing to do with it.

For dangerous game, I want large caliber, a flat meplat with sharp corners for maximum wound track width, minimum wound track deviation due to striking bone, and as deep a penetration as possible.
 
Seeing what modern varmint bullets can do, I see your point. Does it really matter if it only penetrated ~8 inches, if those 8 inches are a crater the size of a beer can.

Here is an example, at ~200 yards with a Hornady Vmax

https://youtu.be/aCqmclsRQmM?t=2m

At home defense ranges, it will be better(worse?).
 
And people wonder why I like a .30 Carbine shooting Soft Point ammunition. 18" of penetration (often 24"-30"). Tissue disruption is excellent!. If you put a carbine-length barrel on an "Advisor" handgun, a 30-round M2 magazine will handily take care of any situation. (It doesn't require a $200.00 NFA tax stamp)!

It works.
 
From a hunters perspective you often have to take shots from less than ideal angles. You may need 20"-25" or even much more for the bullet to reach vitals. If presented with a perfect broadside shot you may only need 12" of penetration or less in order for the bullet to reach vital organs.
 
From a purely defense perspective, you've got two choices. You can treat it as a hunting problem, and use a cartridge/bullet combination suitable for up to 300lb game, and be confident you'll have no problems. Or you can try to get away with something smaller, in which case you find yourself challenged in terms of terminal ballistics and end up doing what the US government has done for the past 45 years - monkeying with the ammo over and over again in the hopes of finding a magic bullet. Of course there isn't one.

When you get right down to it there is almost no difference in physiology between humans and many similar sized game animals of light build. The only meaningful difference from a terminal ballistics perspective is that we wear clothes. Plus of course the fact that in the time it takes a mule deer to run 50 yards before it drops, a human can shoot you back. So DRT overkill is arguably more important with humans.
 
The military is concerned about terminal ballistics on out past a couple of hundred yards. I'm concerned about them within what I consider probable self/home defense distances of within fifty yards or, more likely, within twenty yards.

.30 Carbine, .223, whatever. '06 with 110-grain varmint load. I figure most anything in that range will do just fine. Some cartridge/bullet combinations are better for turning cover into concealment, of course. :)
 
A "real" big game round from a rifle is DEVASTATING compared to a handgun round. There's simply no doubt or question that the wounding capabilities of most any centerfire round using non-FMJ bullets is a higher rated fight stopper than most any handgun round.
Unless faced with body armor clad aggressors, I'd go for relatively quick expansion and not worry about the penetration since the human torso isn't well protected by lots of heavy muscle/bone(flabby fat layers maybe). A rifle bullet that penetrates 2-3" before expanding violently is adequate for the purpose.
The trauma caused by a fast expanding rifle bullet is going to be massive. A fast expanding bullet hitting an arm or leg is going to be more debilitating than a bullet that passes through w/o much expansion.
 
FWIW: Stats from "Under The Gun" by Wright/Rossi/Daly showed that of those shot with handguns, one-third dies; two-thirds live. For rifles, the reverse.
 
Fast expanding bullets equal more energy transfer which equals more stopping power. Several years ago a young man was in the wrong place at the wrong time. A man shooting a 270 with nosler partitions missed a deer and hit the other man walking thru the woods with no orange on. The bullet hit young man low in the front shoulder basically thru the arm pit. Believe it or not the young man thought a wasp or something stung him. Several minutes went by before he ever started bleeding. The young man was a college football player and what I see as heavily muscled. No bone was hit so no expansion occurred. I do believe that if that had been a varmint bullet like the Amax or something similar the results would have been much different.
 
Just an observation, watching most of the hunting shows on TV the hunters/shooters wait a while for the animal to stop and bleed-out. It appears most animals are not 'dead' immediately and need to bleed-out. If these were armed human aggressors then they have to opportunity to continue the fight even though the initial reaction might be to go down to the ground. This happens even with well placed shot location. Quite a few soldiers have been hit with rifle rounds and are still around to tell about it. For home/self protection shot placement is key to ending things. I would figure the majority of rifle and pistol rounds will stop things when properly placed. Even when an assailant if hit with a high power rifle round, if the round doesn't hit the 'game-over' spot you may still end up dead or injured. Your rifle round may have provided mega damage and the assailant may die (hours later) but you may be dead sooner. You need a weapon you can hit the 'game-over' button with repeatedly.
 
"Quite a few soldiers have been hit with rifle rounds and are still around to tell about it."

Unless a FMJ bullet tumbles, there's not as much tissue damage as an expanding bullet. Even a fast expanding bullet will not cause immediate death as it's often loss of blood that kills-not direct bullet effect. Even hitting the brain or spine doesn't cause immediate death but does break the muscle control chain.
This why I want a bullet that causes as much tissue damage as possible as quickly as possible. Causing debilitating peripheral damage is as good as killing in the action of stopping the aggressor.
 
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I agree with Mobuck.

The damage to the human body when hit by a rifle bullet is massive. It is in an entirely different league from any handgun. This doesn't necessarily mean he is going to instantly drop over dead. It doesn't necessarily mean he is going to instantly sttop fighting. But, there is only so much you can do with a reasonable hand held weapon.

IMO, no, the same criteria does not apply to rifles.
 
I shot a lot of pigs, in traps and on hunts. I tried different calibers, guns and bullet types. What I learned through these several hundred pigs was light, fast ballistic tip type bullets incapacitated the animals the quickest. I settled on .223. I was doing this on active farms mostly in the dark. Every shot was taken with upmost care as livestock was always in the area. I took every precaution, but I still wanted to minimize bullet exits. There was an occasional exit wound but not many

This is only my experience, is in no way scientific. I tend to shoot them at short ranges.
 
So, taking the testing results of 50-55gr varmit rounds, of 8-10" of penetration with massive amounts of fragmentation and subsequent large wound channel.

Most reasonable shot angles (discounting angles from far bellow or above) into center mass would put that as sufficient to reaching the heart, and those that do not would be passing through the lungs and other important areas.

As far as clothing is concerned, ballistic tip rifle rounds are going to treat even heavy clothing as pretty much nonexistent. It would have little effect on the penetration.

Thinking about an assailant pointing a weapon, assuming they are actually holding it as a competent shooter would, meaning both hands... If the bullet first strikes an arm, it has about 6" of travel, as it will likely be going through at an angle, which increases the length of material to pass through. Knowing the amount of damage the rounds due, and even more so if striking bone, any arm struck would no longer function. It won't simply be injured, it's likely simply unusable, incapable of function.

If we also subscribe to hydrostatic shock as being relevant, then a complete energy dump of the round is likely to cause more damage than simply that of the wound path.


So while the wounding characteristics may not fit the traditional model of ideal... It seems like those rounds would or should be effective at stopping threats, even determined threats.


So does that seem plausible, or is traditional ideas on wounding the way to go?



One of the things that prompted this, was the general desire for a defensive rifle load that was both effective at stopping a threat, but also have as low as possible risk of over penetration, and misses posing a danger to bystanders in other rooms.
 
While Rickyrick's experience is antidotal, and not scientific, per his admission...

It does stand as good evidence that the lighter ballistic tip rounds are effective on larger animals than varmits/coyotes.

Pigs are very similar to humans, in size, mass, and biological layout. They are not perfect stand ins, as they often have thicker/tougher skin, and denser bones... Meaning they are a bit tougher overall.


So I am definitely inclined to think that using the FBI handgun testing standards for evaluating rfle rounds is not the best way to go about it.

The testing methodology is fine, but the interpretation of results is not going to be the same.


So I think overall that rounds that expand and penetrate deeper into the 12-18" range are probably better stoppers. (Think rounds designed for deer, and how they perform, but not necessarily actual deer rounds) But they will be more hazardous as far as misses and potential over penetration is concerned. Depending on the situation, they may be the best choice. Depending on your desired performance, barrier penetration may be desirable.

Rounds that rapidly expand and reach the 8-10" range seem to be no slouch at stopping the target, while being much safer to use in a home or area where penetration into adjoining rooms or buildings would be considered undesirable.


If that is the case, then it leaves us with a wide variety of rounds we could choose from.. Some that may be deemed unsuitable by the traditional ways of thinking, or the handgun standards some use.


Before I get too far ahead of myself... Rickyrick... Are those light weight ballistic tipped rounds varmit type, or simply light expanding type... Meaning ones that hold together and mushroom rather than fragment?
 
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