Archive for the 'Ammunition' Category

Reader =BCE56= links Ballistic Pressure Wave Contributions To Rapid Incapacitation In The Strasbourg Goat Tests.

Chamberlin observed damage remote from the wound channel he ascribed to the hydraulic reaction of body fluids [CHA66]. Tikka et al. showed that ballistic pressure waves originating in the thigh reach the abdomen. Wounding and delayed recovery of peripheral nerves have been reported [LDL45, PGM46]. Pressure waves cause compound action potentials in peripheral nerves [WES82], and ballistic pressure waves have been shown capable of breaking bones [MYR88].

This shows that, all other factors being equal, bullets that produce pressure waves of greater magnitude incapacitate more rapidly than bullets that produce smaller pressure waves. The Strasbourg test data convincingly supports the pressure wave hypothesis and allows (perhaps for the first time) the fast response time to be modeled as a function of peak pressure wave magnitude.

[ … ]

The trend in bullet design over the last decade has drifted toward bullets with little fragmentation and a higher percentage of retained mass. Bullets that both fragment and meet minimum penetration requirements create larger pressure wave magnitudes and offer improved incapacitation potential.

There is much more at the link.  I find it especially interesting that the authors use a 4*pi()*r^2 model for pressure wave solid angle (as with sound, light and radiation, unattenuated [or scattered] and unreflected).  The pressure wave isn’t forward peaked.

I often claim I have the best readers on the internet.  I really mean it.  This is a good example of that.

And this analysis goes to the heart of the design of the 5.56mm round, which is to induce a pressure wave due to high velocity (KE = 1/2 * m * v^2) and then fragment into shrapnel with multiple wound tracks.

Thanks to reader =BCE56= for that great read.

Remus notes something he calls astonishing.

I’ve seen a lot of pistol shootings, much more than US police would ever see, and much more than experienced by most medics deploying solely with US personnel. And yet, I have zero, not one single experience, where a single gunshot wound from a 9X19 NATO round killed someone prior to them being able to return fire or flee. This includes people shot in the chest, back, back of the head (one hit behind the left ear) the neck and the face. None…

Unfortunately, the same goes for the 5.56 NATO round. I have yet to witness a single shot quick kill with this round… On the flip side, having a patient who was shot by a 7.62X51 NATO or larger round was a rarity. Dead people aren’t patients, they are a supply issue.

That isn’t so much astonishing as it is just bizarre to me.  First of all, I dislike it when someone begins their post with bona fides.  The data is the data, the analysis is the analysis, regardless of your bona fides.

But then the claim makes no sense.  My youngest son had absolutely no complaints about his weaponry when he deployed to Iraq, not did he when he came home.  He was quite pleased with the lethality of the 5.56mm round in CQB and urban combat (MOUT).  He used both his SAW and an M4, and actually both during room clearing operations.

Then there is the issue of what we know about the lethality of the round even at distance.  Everyone recalls the video that made Travis Haley famous, and it’s worth watching again just to demonstrate that in the hands of a competent individual, the round can be lethal out to 600 yards or beyond.

Then there is this picture of an insurgent who was shot with a 5.56m round in Afghanistan at 200 meters.

You think he was able to mount a counterattack?

One final video demonstrates what the 5.56mm round is capable of in the hands of a qualified marksman.

Wirecutter has this video up on barrel twist rate.  Go to his place to see it.

I don’t think the author of the video understands the basic concept and what’s going on here.  This is a screen shot of the video I linked on barrel twist rate.

Bullet tractability is the degree to which the nose of the bullet follows the trajectory.  In the screen shot above, it doesn’t.  This can indeed happen if the bullet is overstabilized, something we concluded in our assessment of this.

In the video (screen shot above) it is explained that this doesn’t usually happen at closer distances, but rather towards the end of the flight path.  In the case of the 5.56mm flight path, we’re looking at around 500 yards effective distance.

The author of the video Wirecutter gave us is shooting at 100 yards.  Basically, I’m saying he has proven nothing at all.  He’s a decent shot, but he hasn’t tested what he thinks he has tested.

And by the way, the twist rate, if you’ll remember, of 1:7 was meant to stabilize the tracer round.  But most twist rates for common ammunition should be fine.  The testing conducted by the Army on both older and newer 5.56mm ammunition involved 1:8 accurized barrels.

Prior: AR-15 Ammunition And Barrel Twist Rates

Via BRVTVS, this is an interesting video.

I have to say that I do have one problem with it.  Mr. Johann Boden speaks as if the only important factor in the high velocity from rifle ammunition (and here he’s speaking of the 5.56mm AR, which is an important distinction in the conversation) is the hydrostatic shock from velocities greater than 2200 FPS.

That simply isn’t so.  We’ve learned over the years that the tendency to tumble and yaw (even in flight, but especially in tissue) and break apart into multiple pieces is one of the defining characteristics of the lethality of the ammunition, in no small part yielding its massive success on the battlefield.

As we’ve discussed before, see Small Caliber Lethality: 5.56 Performance in Close Quarters Battle.

This is an interesting commentary on whether to use JHP or FMJ for personal defense.  It’s situation-dependent, but this memorable quote sticks out.

With these factors in mind, hollow points, with their limited capacity for penetration and greater chance of performing in a way that will stop the attacker with fewer shots, start to sound attractive. When one remembers “there’s a lawyer attached to every round you fire,” and the greater possibility of FMJ rounds traveling through the target and beyond, HP sounds like the more responsible choice.

He also mentions the Lucky Gunner gel testing, which I think is still the go-to spot for data.  Then there is this article from Shooting Illustrated.

I call those who live in this world “Jell-O junkies.” They’re folks who believe that ordnance gelatin holds all the answers. Hell, the FBI has all but said so. At one time I was a card-carrying member of this fraternity, and I, like many who still are, was of the opinion that reliable predictions about incapacitation could be made by looking through those urine-colored blocks of squishiness.

[ … ]

Gelatin testing and the results from it are only tools to be used. If you consider either anything more than an indication of terminal performance or lethality potential, you might be a Jell-O junkie—Don’t be a Jell-O junkie.

Whatever.  Thanks for an uninteresting waste of my time.  I learned nothing from your article except that you want to be smarter than everyone else.  The most informative data comes from one of the comments.

Cartridge; Percentage of stops; Ratio of stops
.32 ACP—65%—–11 out of 17
.380 ACP—–70%—–83 out of 119
9mm—–83%—–224 out of 271
9mm +P—–88%—–170 out of 193
.357 SIG —–94%—–45 out of 48
.40 S&W—–94%—–292 out of 311
.45 ACP—–96%—–142 out of 148
10mm—–too new to include but said to approach 100%

HANDGUN AMMUNITION STOPPING POWER UPDATE
By Evan Marshall

I haven’t read it and cannot vouch for the information.  I do know this.  I carried FMJ when I was in bear country, and I usually carry JHP when I’m around the threats of the two-legged kind.  If I don’t happen to have .45 JHP in my guns at the time and have FMJ (let’s say I’ve been to the range recently), I don’t sweat it.

John Basilone said it was okay.  I trust him more than I do Shooting Illustrated.

Glomming off of Wirecutter’s hard work (WiscoDave sent this our way), here is a very good video of 300 BO Q&A by someone who sounds like an experienced practitioner.  I don’t shoot 300 BO, but if I wanted to start, I’d begin with his video.

From a reader, news from Virginia.

Though one of the men in the group was ineligible to buy a gun — and had been previously convicted of making a false statement on a firearm consent form — he made the purchase without a hitch.

Police took the video footage from the gun store in the course of investigating a homicide, according to search warrants filed in Danville Circuit Court.

Days after seeing the video, police found the man riding in a Buick with a Glock 45 tucked under his seat — a round in the chamber — and a magazine on him. Court records show police arrested and charged him with possessing a gun as a non-violent felon, carrying a concealed weapon and felonious possession of ammunition.

Though federal and state laws prohibited him from possessing ammo, there were no background checks required to buy it, as there are when purchasing a gun at a store.

In fact there is no background-check infrastructure in the state to stop a felon from purchasing ammo, Virginia State Police public relations manager Corinne Geller said.

The state police handles background checks for firearms purchases, referring applications to the Virginia Firearms Transaction Center in Richmond. The center combs through four state databases and one national database maintained by the FBI to check a buyer’s criminal history, mental health history, protective orders and other disqualifying factors when they go to buy a gun.

But of course.  Instead of reversing the unconstitutional gun sales background checks, since they don’t stop crime, just expand it to ammunition as well.  When a process fails, double-down on it, the progressive way.

They are eventually going to implement a new AWB, and they will eventually come after ammunition too.  Without ammunition, a gun is a paperweight.  Get it now while you can.  Otherwise, red flag laws may sweep you into their net.

By the way, I fear that the good folks of Virginia are going to fall victim to the progressives in Northern Virginia, just as North Carolina has to Mecklenburg and Wake Counties.

Shooting Illustrated:

Nothing particularly appeals to me about either cartridge, but if you’re into one or the other, or both, it would seem that the sweet spot is 110-gr BO, with the best accuracy coupled with about the highest muzzle velocity.

Outdoor Life:

After more than a century of flattening the world’s biggest, meanest, and tastiest game animals, the .30/06 Springfield remains an incredibly well balanced, versatile, affordable hunting cartridge. With modern ammo it shoots 100- to 200 fps faster than it used to. If it was good enough to stop lions, rhinos, buffalo, and elephants 100 years ago, it’s probably good enough to stop deer, elk, and moose today.

He makes his case with unction when comparing the ballistics to 6.5 Creedmoor, .270 Winchester, and other cartridges.  The 300 Win Mag comes out on top in just about every category which is expected, but just by a little.

But when comparing ballistics, he looks at energy (ft-lb), and hydrostatic shock is important as well, so I’m not entirely convinced.

My conclusion is that the cartridges are closer than one might think, but one interesting thing is that the 270 Winchester beats the 6.5 Creedmoor in carried velocity at distance, energy, and bullet drop.

While he says makes the case for the .30-06, I might conclude that he really makes a better case for the .270 Winchester.

Continuing with the conversation we were having a few days ago on new cartridges that answer questions nobody has asked, this new cartridge may be the next in line to fail.

Nosler was the first company to launch a new super .22 with the release of the 22 Nosler. It boasted “close to .22-250 velocities” in a short case that could fit into a standard AR magazine. This cartridge was soon followed by Federal’s release of the .224 Valkyrie, which took on a bit of a different appeal. You see, the 22 Nosler was designed as a super-fast varmint caliber with 1-in-8-inch twist or 1-in-10-inch twist barrels offered to stabilize bullets closer to those of the .22-250. This provides a distinct advantage over the 5.56 with similar weight bullets. The Valkyrie addressed more of the long-range interest with its attempt to push 70-90 grain bullets past 2,800 fps.

These velocities are respectable, especially considering that neither has an overall length of more than the standard .223 Remington. There will be many who point out that the .220 Swift was the original king of small-bore magnums, but it really needed a fast twist barrel and long action to make it shine. We have finally seen the shooting sports embrace long, heavy-for-caliber bullets. It has been long awaited, but as I am writing this, Hornady Manufacturing is pushing to get yet another super-cartridge through the Sporting Arms and Ammunition Manufacturers’ Institute process, just as the sport has been chasing smaller, lighter calibers to perform further down range.

The 22 Creedmoor is the newest of the overbore magnums to hit the market. With the capacity of the now famous 6.5 Creedmoor, the 22 Creedmoor is just a necked down variation on the same cartridge. So, what can it do that the others can’t? To be honest, it is not that much different than, say, the .22-243 or the .22-250 AI, but what all but a few custom builds have lacked, the 22 Creedmoor has embraced. It was never designed to shoot lightweight bullets at 4,000 fps. Though it will do that easily, the 22 Creedmoor was built with long, heavy .224 bullets in mind. The 22 Creedmoor will come standard with a 1-in-7-inch fast-twist barrel, and combined with the increased volume inside its case, you can push those long pills over at 3,450 feet per second! This is a distinct step up in performance.

Oh, I don’t know.  Maybe it’s just the ticket if you want the rifling blown out of your barrel.  I don’t see this as stiff competition for the 224 Valkyrie, but who knows?