Oversimplifying Ammunition Ballistics
BY Herschel Smith6 years, 11 months ago
Via Say Uncle, this comes to us from Tam.
Super Vel Ammo: I have to vent.
What kills me is how they’re hyping 90gr +P .38 Spl & 9mm and 185gr +P .45ACP bullets as if the last thirty years of accumulated terminal ballistics knowledge hadn’t even happened.
Flying dimes with no sectional density moving at Warp Factor Six are how we got Miami and then wound up spending twenty years wandering in the .40 caliber wilderness, and the shit is being pimped by people who should goddam well know better because, I dunno, Cameron Hopkins is a nice guy or something and the boxes make older gunwriters feel nostalgic.
Oh dear. The lady doth annoy me sometimes. So let’s discuss this a bit. She’s referring to sectional density, which is technically calculated as the ratio of mass over the cross sectional area, or SD = M/A. The gun community simplifies that by ignoring the value of Pi in the computation of area, and converting mass in grains to pounds with the conversion of 7000 grains per pound. Like this.
SD = M / (7000 X r^2)
The resultant value is dimensionless and totally meaningless unless in the context of comparison to the sectional densities of other bullets. So for instance, the 230 grain .45 ACP bullet has a sectional density of 0.162, while the 185 grain bullet has a SD of 0.130.
But in reality, the lighter bullets aren’t travelling at “Warp Factor Six,” and a 185 grain .45 ACP isn’t a “flying dime” compared to any handgun round on earth. And as for that matter, the 45 grain 22 magnum round has a SD of 0.128, which is reasonably close to that of the 185 grain .45 ACP. Does that mean we should all dump whatever we currently shoot and adopt the .22 WMR?
No it doesn’t, because SD isn’t the only thing on earth to consider. If it was, then Lucky Gunner would show that the penetration and expansion of 185 grain rounds sucked, while the 230 grain rounds succeeded. Oops. Guess she got that one wrong.
There are multiple things to consider, like (a) velocity, (b) consistent expansion, (c) penetration depth, (d) wound track, etc. I’ve pointed out before that while I shoot the .45 ACP and I like it, I also like much higher velocity rounds. Let’s rehearse what we saw with the FN 5.7 shot at Fort Hood.
The FN 5.7 pistol is constantly maligned or underestimated in many gun forums and articles, often by people who have never experienced shooting the pistol. Subjective comparisons with the .22 magnum or categorization as a sub-par .223 round create confusion about the effectiveness of the FN 5.7.
Enough time has passed after the terrorist attack at Ft. Hood. The shooter, Nidal Malik Hassan, has been arrested, tried and sentenced. The media has moved on. Now we can begin to analyze the impact of the FN 5.7 and address the question of lethality.
Using SS192 and SS197SR ammunition (common commercial 5.7×28 ammo), several 20-30 round magazines and an FN 5.7 (shooter also had a .357 revolver but did not use it), Hassan killed 13 and wounded 32 people.
Many armchair ballistics expert criticized this result as proof that the FN 5.7 platform is not lethal enough because of the proportion of the fatalities to the wounded. Others have proposed that had Hassan use another type of pistol, 9mm or .45, there would have been more fatalities.
If you look at this Wikipedia link and look at the list of casualties, one can come to a very eye-opening conclusion.
Fort Hood shooting – Wikipedia, the free encyclopedia1. 11 people were shot center-of-mass (COM), one was shot in the stomach and one was shot in the head. All 13 died. All 11 victims who were shot COM did not survive.
2. 3 of the 13 people who died, tried to charge Hassan, but he stopped them with COM shots.
3. The 32 people who were wounded were hit in the arms, legs, hips and shoulders. None of the wounded survivors were shot COM.The following conclusions can be drawn:
1. The FN 5.7 is a very lethal round CQB because all 11 victims who were shot COM died. No survivors for those hit COM.
2. The FN 5.7 is a real stopper, because 3 tried to charge Hassan at close range and were stopped by COM shots.
3. One of the fatalities was shot in the stomach, and died. The fragmentation of the SS197R round can create a hail of metal shards that can cause serious internal organ damage and bleeding in the stomach.
4. None of the 32 people who were hit in the extremities, hips and shoulders were able to muster a counter-attack because the FN 5.7 must have shattered or broken bones. The high rate of wounded vicitms to fatalities was the direct result of the shooting ability of Hassan (or lack thereof), and not because the 5.7×28 round is not lethal.
5. Sgt. Kimberly Munley (base civilian police), one of the first responders, was immediately disabled with 5.7×28 bullet shrapnels to her wrist and a second 5.7×28 bullet broke her femur. The light 5.7×28 commercial ammo showed that it can shatter large bones due to its velocity
6. According to medical personnel, there was so much blood in the room that it was difficult to get to the victims because the floor became very slippery. One can conclude that the commercial 5.7×28 rounds can fragment or tumble, causing immense blood loss.
7. It took five bullets (which I assume was a 9 mm) from Sgt Mark Todd to stop Hasan. And he survived his wounds (no available info on where he was hit, except that one of the bullets paralyzed Hasan).In conclusion:
1. The FN 5.7 is definitely a very lethal round. 100% fatality for COM shots.
2. The FN 5.7 is a man-stopper. Three military men tried to charge Hasan, and all three were stopped.
2. The FN 5.7 is a very incapacitating round, if extremities are hit, because it is powerful enough to break the femur (which is the largest bone in the body)
3. The fragmentation or tumbling effect of commercial ammo can cause a lot of blood loss.The FN 5.7 is a very effective weapon. It is as effective as, or arguably more effective, than any military or civilian pistols in the market.
It is unfortunate that the jihadist Hassan used this weapon against U.S. soldiers.
I have an FN 5.7. You don’t want to be shot with that round, especially not the ammunition travelling 2200 FPS (the red box ammunition versus the blue tip sporting rounds). Velocity isn’t everything. If it was, I’d carry a 6″ barrel .357 magnum with me everywhere. There is the issue of weight, shape, form, and so on the list goes.
But oversimplifying this to some idiotic rant about turning back the hands of time on 30 years of research is silly and does nothing to serve the gun community.
By the way, there is nothing wrong with the .40 S&W, even though she likens it to wandering in the wilderness for 20 years, any more than there is anything wrong with the 10 mm (which is similar). The notion of high velocity round to which she refers can be studied here. The comments are laughable. There is this one.
In the ’60’s I was a cop in a moderate size PD in Texas, an officer shot a suspect in the chest three times with .357 Super Vel 110 grain bullets. Even though the bullets were traveling 10,000 miles an hour none of the three penetrated past the ribcage and they expanded well and destroyed his ribcage he almost knocked the officer down running passed him. The next day Super Vel was removed from my revolver.
If you believe that someone shot someone else with three .357 magnum rounds, or even one of them, and it failed to penetrate past the rib cage (in other words, it only penetrated the clothes and skin), then you’re dumber that a box of rocks. That cop missed. Or the person was lying about what happened. He was fabulating.
Be careful what you read on the interwebz.
On January 11, 2018 at 10:53 am, Fred said:
I don’t read or watch anyone or anything that uses the gratuitous cussing of God as an exclamation. She cusses that which does not know but rest assured, she knows that evil is real.
On January 11, 2018 at 2:15 pm, AZwild said:
I got into firearms after college, when I could buy my own.
Ruger SR40 an 40c we’re my first two striker fired pistols. Wife likes the 40c, and generally likes the 40S&W more than 9mm.
Bought a Glock 20, love the 10mm an would gladly sell the SR40 to get a G29 for CCW.
Caliber rants are interesting to me only as a view to how people think regarding bullets and their perception of ballistics. The YouTube channel, Active Self Protection shows just how criminals respond when shot….all of them stop thinking about the crime they initiated.
On January 11, 2018 at 2:34 pm, Herschel Smith said:
@AZwild,
Yea. Shoot what you’re good at, what you’ve been trained to, and what you like. If you want lighter faster ammunition, then shoot it. If you want lead ball, then shoot it.
I find trying to herd gun owners into a single narrative for what’s “best” based on what so-and-so said to be amusing and stupid.
On January 11, 2018 at 6:00 pm, Tam said:
Your ideas on terminal ballistics are cute. Don’t quit your day job to talk guns with grownups. :)
On January 11, 2018 at 6:11 pm, Herschel Smith said:
@Tam,
At least as cute as your incoherent rant.
On January 11, 2018 at 9:13 pm, DonM said:
Rule of thumb. Tam knows a lot about Guns. “Captain” Morgan doesn’t make up for ignorance.
On January 11, 2018 at 9:27 pm, Ned said:
Oh thanks Tam. When anyone I don’t want to talk to anymore asks for terminal ballistics information, i’ll refer them to your post.
On January 11, 2018 at 9:30 pm, Herschel Smith said:
@DonM,
Mmmm … okay, then that settles it. As for Captain Morgan, I don’t know anything about him. You’ll have to take your issues with him up with him directly.
Thanks for your visit though.
Herschel Smith, P.E.
On January 12, 2018 at 11:56 pm, jajaja said:
Hey Tam, you should open comments on your website.
What’s a matter? You only like to dish it out? Thought so…
On January 13, 2018 at 12:01 pm, Tam said:
“jajaja”*,
I don’t have comments on because I don’t care about your opinion. You specifically.
If something I write gets your panties in a twist, like it did Herschel’s, you can bitch about it on your own blog, like Herschel did. I don’t owe you a whining corner.
Have a great day!
*(I’m sure that’s your given name. Being lectured about cowardice by someone hiding behind a pseudonym is always amusing.)
On January 13, 2018 at 3:09 pm, Joshua Smith said:
@Tam,
I like .40 S&W very much. I have even shot it at criminals, although I have only been shot at with .38 and 9mm.
I also think that when you shoot a person with almost any handgun in existence, they are very likely to either die or become incapacitated. Extreme idea, I know. But I like trying to push the envelope with my opinions.
I find it curious that you would go to the Internet to post an inane rant at a time where you’re clearly put off (by what, I haven’t the slightest idea). That’s not something I’ve ever done, and I would advise anyone against it.
His day job is working as a Professional Engineer.
I’m not sure if you’re just slow, angry, or jerking yourself off over “MUH FLYING DIMES!!!”, but I find it all very amusing. :)
On January 13, 2018 at 8:23 pm, Ned said:
Looks like the Tam fan bois posting here are as coherent as Tam. Nice that they all understand the same language.
On January 15, 2018 at 2:36 am, Jorge said:
High velocity pistol rounds can be really vicious. I remember reading something by WE Fairbairn (a big .45 proponent) mentioning a 7.63 Mauser pistol round doing a number on someone’s arm/wrist, shattering the bone.
As for .40… it was marketed as the Goldilocks round, most of the performance of .45 ACP and most of the capacity of 9mm. All the tests that I’ve seen suggest that this was a rare case of honest marketing.
On January 17, 2018 at 12:09 am, jajaja said:
Tam’s triggered…A simple observation is classified as “being lectured about cowardice”. That’s what happens when you are insular and fragile.
On January 18, 2018 at 12:30 pm, raz-0 said:
I’ve been following Tam off and on for seems like forever. I find her an interesting and amusing blogger, but I’d argue she only fairly recently started taking the shooting thing seriously, or at least talked about such. As for how much she knows about guns, well from what she has posted over the years, the level of technical info is moderate, and the density of info over time is low.
So…
1) discounting 185gr +P .45acp as ineffectual is just stupid. Sorry, but there’s a ton of work that has been done on many, many cartridges as well as case studies, and 185gr .45acp isn’t a slouch in any form.
2) WTF does it have to do with the miami shootout? They bought 2″ snubby .357 revolvers loaded with .38 special to a rifle fight. Also the terminal ballistics of missing suck. The +P loads if my googling is right were 158 gr. They didn’t give up mass they gave up velocity, twice. Once going from .357 to .38+P, a second time by relying on 2″ barrels.
3) Criticise 90gr 9mm and 38+P all you want, but how the hell is it nostalgia from the 80s where lessons were forgotten? About the only thing that light I recall from then were glaser safety slugs. Which is a whole different kettle of fish than say a 90gr solid copper. Supervel was before my time, but hey go look around, it hits the FBI 12″ in gel result from new old stock. They were out of business by 74 and I was probably jsut about walking by then. IT certainly wasn’t FBI issue during the miami shootout.