10mm Advocacy Article

By Thomas Martens, thomasrmartens@yahoo.com
please contact the author at the above e-mail address with any
questions or comments

(For those of you who have sent me so many kind emails on this article, I'd like to thank you.  I have moved it to my personal website due to the "Calibers" site being down for so long.  I'd like to thank Todd for being the first one to post this article.  Check back on occasion, as I will updating this article, and adding a TON of expansion pictures, and more data from Double Tap ammo.  Tom)

If you have read this article, and just want to see the new expansion pictures, there are links at the end of the article.

Last updated 14 May 2007

This article deals with the 10mm automatic pistol cartridge, sometimes called the 10mm Norma. I’ll dispense with the history of the cartridge; there are enough articles around about that.  My purpose is to expound upon the merits of this round, and to present some data to support my assertions.  It is my belief that this cartridge, though never really popular, has not only suffered from the poor reviews many in the gun press have given the round, especially Chuck Taylor *, (it’s generally disrespected by most of them) but also from a total lack of understanding of its strengths. Tell me, when is the last time you saw an article on any gun for the 10mm.  There are articles galore on the 1911, .40 Glocks, Sigs, etc.  The 10mm is old news.  Sexier cartridges have come on the scene like the .357 SIG and the .45 GAP.  Heck, I’d swear there are more articles about cartridges like the .45 Long Colt than the 10mm.  That’s a shame.  I don’t pretend to know why they are so anti-10mm in the gun magazines.  Every once in a while they’ll say something nice about it.  Ayoob seems to at least appreciate the 10mm, and Rauch likes it too – though neither as much as the .45.  They (the gun writers) are not the only culprits though.  There can be no question that the FBI’s lightening of the round in terms of velocity, and the subsequent introduction of the .40 caliber cartridge are also, in part, responsible for the 10mm’s lack of wide spread popularity. Still, this is an excellent cartridge - the best all around cartridge for a handgun, in my opinion. Finally, however, interest in the cartridge does seem to be on the rise at long last, and many .40 caliber shooters have either gotten the bug for more power, or have made the progression to the 10mm because they re-load the .40, and they can use the same dies and many of the same powders for the 10mm.

The approach I will take in this article is primarily to show why the 10mm beats the .45 ACP.  But I will be making a few references to other popular defense calibers as well. 

About the Author

Before I begin in earnest, bear with me, I’d like to reveal some of my prejudices and a little background information about me to orient the reader.

I joined the Marines at 17 and was fortunate enough to pass number of strange tests, and a host of other things before I received a Category I Top Secret clearance and sent to Camp David to guard President Reagan.  We carried a bunch of different weapons up there, and one of those we carried around a lot was a1911 .45.  More than a few of us owned our own, and were even known to quietly replace our issue .45s with our personal guns (and ammo sometimes) while on duty. My last 18 months or so I lived on a farm in Pennsylvania and so had plenty of land to take my .45 and train, train, train with it. But I also was curious about the 9mm, and in 1985 bought a gun few of my fellow Marines had ever heard of, a Sig Sauer P226. Though I really liked the gun, particularly its large magazine capacity, I was less than enthralled with the 9mm cartridge - save that I could shoot it fast and accurately - something I’ve since learned that can be done with any handgun with a bit of dedication and practice. I left Camp David in 1986 before a single Beretta arrived. Suffice it say we hated the idea of a 9mm anything replacing our beloved .45s. I love the .45 ACP, and I own more than one gun for this cartridge. To me, I just feel safe with a gun chambered for that round, and nothing, save the 10mm, makes me feel better. However, after a lot of thought, reading and research, a few years back I sadly relegated my .45s to back up roles for home defense, in favor of the more potent, and more effective 10mm auto.

Crowds

When it comes to ammo selection, I’m a convert from the lightest and fastest camp to the medium to heavy weight bullets. Thing is, even when it comes to heavy, I want the fastest "heavy" I can find. In my Colt Delta Elite, and my Glock 20, I load up with Pro Load’s 180 gr Gold Dot HP. In my Delta Elite this load, rated at 1200 fps, comes out nearly dead on at 1207fps, and at 1176 fps in my Glock 20. At well over 500 foot pounds of energy each, these are hot loads. I also like the Winchester 200gr Black Talons in my Glock 20 loaded up with 8.2gr. of Long Shot and the 6” barrel.  A couple of other bullets that seem to work very well at 10mm velocities is the PMC 180gr Starfire that I load up with 9.6gr. of Long Shot, or the Remington 180gr Golden Saber.  If you like carrying reloads for defense or hunting, these loads have worked well in my tests, even out of the Glock 29.  I also carry the 180gr Pro Loads in my Glock 29. All the testing I’ve done with this round show it is also a great performer out of shorter barrels; something about that Gold Dot bullet. However, I have been known to carry the Hornady 155gr XTP in this gun.  I was never a believer in this bullet as the meplat just looks like it will not open up – but looks can be deceiving.  I trust Steve Hornday’s designers.  All my (unscientific) tests have showed the XTP to be a top performing bullet design.  I load my Colt .45 with Cor Bon’s 230 gr JHP+p. My Para-Ordnance P12 gets loaded with the Hornady 200 gr +p XTP. I’m not comfortable with the heavier loads in this gun, as I do want some hope of expansion. At about 940 fps, I’m hoping for it, but not expecting it too much. I really doubt I’ll get any though with the 230 gr loadings; they’re too slow.

I abandoned the lightest and fasted crowd because I worry that these rounds, though likely to expand, will stop before they get too deep to do much damage. If your adversary is 6’2" and 225 lbs, or 5’10" and 225 lbs for that matter, of the eight or nine or inches of penetration you might get with a light-and-fast, 1/2 of it will be fat and/or muscle. Take a look at the guys who are or who have been in prison (something like 75% of all crimes are perpetrated by ex-convicts), few of them are small men. The shock value of a light-and-fast will be lost on disrupting blubber or penetrating layers of muscle. I want something that will get through the fat and muscle, and still have enough left to get to the vital organs. A light-and-fast is less likely to do that. Here, far from disagreeing with Chuck Taylor, I’m with him.

Why 10?

So let’s look at my reasons for switching to the 10mm, and my reasons for thinking it is THE best cartridge around.

I am approaching this article, and my home defense, with the intent that the ammunition I choose will at least have the possibility of expanding in an adversary. For those of you who carry .45 ball or JSPs because you trust no round to expand, and hence believe there is no point in trying, I give you your due. There is no popular self-defense round which makes a bigger hole than the .45 ACP. A 10mm auto FMJ, or JSP cannot make a hole as big a .45 ACP FMJ or JSP. The 10mm auto can’t win here. But if expansion is important to you, or energy, or momentum, or velocity or bullet weight variety, 10mm beats .45 ACP nearly every time.

Please note the attached charts.

I have attempted to give as close as possible an apples to apples comparison when it comes to the guns. I own a Colt .45 ACP with a 5" barrel and a Colt Delta Elite with a 5" barrel. These are the primary test guns. Below this chart is the backup test guns chart: a borrowed Glock 30 was used, and my personal Glock 29.

These are all the loads I’ve tested in my guns, sorry if yours isn’t here.

Energy Junkies

If you’re an energy junky, which I have found a surprising number .45 ACP lovers are, then take a good hard look at these charts. Even those of you who love the high velocity, high energy and lightweight .45 rounds need to look at the numbers the 10mm puts up. As a former member of your camp, certainly the .45 ACP 165gr JHP from Cor Bon is a screaming hot round, with lots of penned up energy to dump in the bad guy. 577 foot pounds of energy is impressive, indeed. But the 10mm wins the energy battle. The .45 ACP has but one loading, the 165gr, that reaches these energy levels, and about three different makers of this loading. With the 10mm, I have chronographed fully 6 loads (and there are more out there!) in four different bullet weights that BEAT the energy levels of the 165gr .45 ACP loads by a minimum of 20 foot pounds of energy each: some by substantially more. And these loads give a wide range of bullet weights, from the screaming hot 150gr loads, to the hard pounding 180gr Cor Bon. If you’re into light loads that create big stretch cavities you should be looking at the 10mm, not the .45 ACP or the .40 S&W or even the .357 magnum!

Momentum Maniacs

Many of the 10mm loads beat the .45 here too. Momentum basically aids in penetration, so rounds with high numbers here should get good penetration, provided that they don’t expand too quickly, like the 165gr .45 ACP loadings would. (Though I use “Power Factor” in place of momentum the charts, it’s basically the same thing.  So, a high power factor load will generate an equivalently high momentum number.)  Still, the 230gr .45 ACP from Cor Bon has a 217 Power Factor, the most in the caliber. And keep in mind this is a +p load. Your run-of-the-mill 230gr have a Power Factor of around 199. Yet, the 10mm has half a dozen loads which meet or exceed this Power Factor. If you like good penetration potential, why aren’t you shooting the 10mm?

Bullet Weight

Another area where the 10mm beats the .45 ACP, the 9mm, .40 S&W, .357 magnum or any other cartridge is in the department of bullet weight variety. Think about it, the 10mm has bullets for defensive use alone in weights of 135, 150, 155, 165, 170, 175, 180 and 200 grains. That’s eight weights! Plus the 190gr, and 220gr weights which are NON-JHP and for other shooting applications.  The .45 ACP has 165, 185, 200 & 230 grains – four different weights. 9mm has 90, 115, 124, 125, 127,130, 135 & 147 – that’s eight different weights, but I’m being nice by separating out the 124, 125 and 127gr loads. .40 S&W has weights of 135, 150, 155, 165 & 180, that’s five different weights. .357 magnum has 110, 125, 140, 145, 158 & 180. That’s six, but I wouldn’t recommend using the 180gr load for home defense – if you want heavy in .357 magnum, use the medium wt. loads. I like the 145gr Winchester Silvertip. So you see, the 10mm has a weight, and a load for every one.

Expansion

Only the lighter weight .45 ACP loads are going to open up in an adversary with any reliability. This problem is compounded in the short barrel .45s.  I don’t have sophisticated labs, nor the money to do such tests, but I’ve got meat, and big phone books to soak, and old clothes to put over this stuff, and here’s what I’ve discovered:  .45s work well in all bullet weights out of a five inch barrel.  But shorten it to Glock 30/36 length, and the heavier bullets don’t want to expand.  Loser bullets that I’ve tested in a Glock 30 are some of the most respected in the .45 crowd.  Sorry, these are my results, and I’m only sharing them with you.  The 230gr crowd:  Federal Hydra-Shok barely expands, Federal JHP Hi-Shok doesn’t expand; 200 gr. +P Pro Load (a Gold Dot HP bullet) shows minimal expansion, and was a huge disappointment to me.  185gr Remington Golden Saber opens a bit, but shoots the unexpanded core forward, leaving the jacket behind.  But the full power 10mm loads are all generating upwards of 1200 fps, well above the expansion threshold for most any decent hollow point. Perhaps only the .357 magnum achieves such results, and the new .357 SIG, but we go back to dealing with some lighter bullets, and lower momentums.

Hunting

You can hunt with a .45 ACP, though not that many people think of it as a hunting round. Perhaps only the .357 magnum is used with any regularity for hunting when it comes to the usually self-defense oriented calibers. With the 10mm you can buy some excellent hunting loads that out class any other caliber. Cor Bon offers two good loads for it and any heavy weight bullet like a 180gr or 200gr form Hornady or Cor Bon will do quite nicely on game sized animals like deer and wild pigs. Also, the 10mm is a very flat shooting round. I’ve hit man sized targets out to 100 meters with it ten for ten, and I really don’t need to use that much “Kentucky elevation”. Try shooting a 230gr .45 ACP slug at 100 meters without raising the bore up a good bit.

Cross Sectional Density

I’ve gone to a bit of trouble trying to keep the comparison between 10mm and .45 ACP similar in terms of gun types, but how about loads? This is tougher. We will certainly look at all the loads offered, but in terms of a direct comparison, we are limited to only the 200gr loads, 165gr loads, and the 180gr 10mm loads vs. 185gr .45 ACP loads. OK, so for those who must have the heaviest slug, i.e. 230gr, .45 ACP wins again. Stop reading now – quit while you’re ahead.

Let’s look at the 200gr loads first. The 10mm cartridge is limited here, for only Hornady offers a 200gr full load which could be used for defense. Note the charts above. Typically, .45 ACP standard pressure loadings of 200 gr slugs weigh in at about 946 fps in my Colt .45 ACP for 398 foot pounds of energy. Out of my Delta Elite, Hornady’s 200gr XTP averages 1099 fps, for 537 foot pounds of energy. This is a huge difference if you are concerned about a slug opening up in a bad guy. Fact is, the 200gr standard pressure .45 ACP loadings are slow, and less likely to expand. What about the 200gr +ps? However, I’ve chronoed Cor Bon’s 200gr, and Hornady’s 200gr XTP, and both are wanting compared to my beloved 10mm. In my .45 the Cor Bon’s are a disappointing 1029 fps for 470 foot pounds of energy, and the Hornady’s turn in a bit better at 1048 fps, for 488 foot pounds of energy. My Delta Elite wins this battle hands down. I’m talking winning the velocity battle by from 47 fps to 153 fps, which translates to a substantial boost in terms of foot pounds of energy.

Certainly load selection here is won by the .45 ACP; it’s just a lot easier to get ammo for it. But with the internet, and a little patience for the loads to come in the mail, you can get some terrific self-defense loads for this cartridge. Though the 200gr JHP is probably the least popular load for the .45 ACP, the three or four loads out there beats the 10mm’s one. But I’ll take that one load any day over the .45 ACP slower loadings.

What about the 180/185gr loadings? Well, let’s compare the loads. This may be the only of the three loadings where the 10mm actually has more selection than the .45 ACP. Problem is, most of the 180gr loadings now are of the –p variety, i.e., more in tune with .40 S&W loadings – about 950-1030 fps. Still, there are some good loads out there that beat the .45 ACP ballistics. Look at the Cor Bon 180gr load, pretty impressive ballistics, 1268 fps, 643 foot pounds of energy, or the Hornady load: 1230 fps for 604 foot pounds of energy. You just can’t get that from a 185gr .45 ACP. If you’ll indulge me 5 more grains, the Winchester Silvertip is a solid performer at 1240 fps and 597 foot pounds of energy. You won’t find this in a .45 ACP. Triton’s 185gr load clocks in at 1081 fps, and, once again, we’ve had to go to the well and use +p ammo to even get close. The standard pressure loads aren’t even close. Federal’s 185gr JHP gives 993 fps and 405 foot pounds of energy, the Remington Golden Saber averages 1001 fps for 412 foot pounds of energy, and the Winchester 185gr Silvertip averages 953 fps and 373 foot pounds of energy. Keep in mind that the greater cross sectional density of the 10mm allows for deeper hollow-point cavities, and it’s greater velocities give you a round with excellent expansion possibilities, a large recovered diameter, and good penetration. As for the –p loads, they mimic .45 ACP ballistics.

When it comes to the 165gr loadings, I really don’t care for them at all in a .45 ACP. Not enough mass to do the job for me, and if they open up, too little penetration. One guy compared it to shooting an empty can of tuna out of your gun; the image stuck.  The 10mm loads are out there, but I really don’t like them either. If you like light bullet weights, my .45 ACP clocks in with the Cor Bon’s at a nice 1255 fps with 578 foot pounds of energy. A pretty wicked load, but I have doubts it’ll punch a deep hole in a heavy, thick man – probably just piss him off. To be honest, the only 165gr 10mm load I’ve chronoed in my Delta Elite is the Cor Bon 165gr, which comes in slower than the .45 ACP. I get 1236 fps, and 560 foot pounds of energy. Seems if you like this load weight, .45 ACP and 10mm are about even. I think the 10mm will get more penetration here though, because the bullet is longer. It will require the peeling back of more material to expand it fully, and thus will create a longer cone of destruction and be better able to reach the organs and blood vessels deep in the adversary.

Down Loading

Reloading

I don’t down load my 10mm much, but this is one aspect of the cartridge that must be factored in to the argument for the 10mm over the .45 ACP. The 10mm “lite” or what I like to call the –p, is nothing more than the ballistic equivalent of a .40 S&W, another good cartridge, to be sure. Only available in 180gr loads, the “lite” 10mms matches the ballistics of a 185gr .45 ACP. The big advantage of this, though, is the fact that it can be done. If your looking for a round that recoils less in 10mm it is a simple process to buy one of the 180gr lite rounds. Can’t do this in .45 ACP unless you buy one of Federal’s 165gr Personal Defense Loads, a light, low energy round that I really find no use for. It’s my opinion, only, of course. In the .45 ACP, you basically have a round that you have to load UP to get near 10mm ballistics, whereas all the typical .45 ACP rounds fall short in terms of energy, momentum, expansion, penetration or whatever factor you look at (save bullet weight and non-expanded diameters). With a 10mm, you have the automatic’s equivalent of a .357 magnum type gun, capable of shooting the milder .38 specials (in .40 S&W) if need be.

It makes sense to discuss re-loading the 10mm here – though in certain circumstances, “handloading” may be a better moniker for this section. 
”Reloading” refers to range ammo, usually from brass already fired.  “Handloading” refers to virgin brass, more than likely, and that you are doing a special loading of the ammo.  A pet max load or special deer load, for example, or a load you have found to be an accurate target load.  You’ll weigh every charge, and quality control is paramount, whereas with range ammo you won’t need exact powder measures, and you are more concerned with getting 300 rounds done so you can hit the range tomorrow. 

10mm ammunition is more expensive than most other calibers – IF YOU DON’T KNOW BETTER.  If you don’t reload, you must shop the internet for your factory ammunition.  Affordable 10mm is out there, you just may have to dig for it a bit.  However, an alternative is to load your own.  There are a couple of alternatives out there for this: you can buy a progressive reloading machine, which will allow you to crank out lots of ammo at a fairly rapid pace, but will cost you more in initial set-up cost; or you can buy a single stage reloader for literally hundreds less in start-up costs (and decreased output). 

Finally, you  probably want to know how much you will save by reloading.  Truth is, you will not save a dime for the first 6-18 months.  Depending on how much you shoot, and what kind of set-up you buy, your initial outlay will preclude you from actually saving anything.  However, if you write off that outlay – and depending on the components you use, AND you don’t charge yourself for time spent, a box of 50 rounds of practice ammo will cost you about $5.50 – give or take $0.50.  Beats buying Blazers at Sports Authority for $13.00 a box.

I still have a single stage set-up.  I like the hands-on aspect of it, and being able to have quality control at every stage.  Plus, it’s a hobby for me, and I don’t mind spending the extra time.

Short Barrel Balistics

Now let’s take a look at how some loads do out of short barrel.

I think it is pretty clear that it does not matter what the barrel length, the 10mm wins this war too, and only loses the battle of bullets with non-expanded diameters.

Conclusion

One last thing. Though I have not divulged the numbers here, the .45 ACP did win in another category: that of standard deviation. I don’t pretend to know why this happens, but the .45 ACP demonstrated an average deviation of 12 fps out of the Colt, and 14 fps out of the Glock 30, whereas the average deviations from the 10mms were 20 fps from the Colt and 21 fps from the Glock 29.  If this trend is troublesome to you, I suggest purchasing Pro Load ammunition.  It is, hands down, THE best ammunition on the market in terms of low standard deviations, flash and just over-all consistency.  You won’t always get the highest velocities with Pro-Load, but you don’t always need the highest velocities.

I hope I’ve convinced the reader that, if nothing else, whatever bad press they have heard about the 10mm cartridge is wrong, and that the cartridge is not only excellent, but a worthy candidate for ANY shooter looking for a home defense gun. If you’d like to respond to this article, please, do not hesitate to e-mail me.

Footnote

He states in his excellent 1997 Combat Handgunnery book, on page 79, that the 10mm "is uncontrollable, exhibits excessive muzzle flash/blast and demonstrates massive over penetration". Certain loads do penetrate excessively, but there are so many good 10mm loads, in so many different loadings and bullet weights, that plenty of good loads are available. Also, I admit some loads flash and blast a lot. Cor Bon’s stuff does not flash much at all. And regarding the "uncontrollability" factor, I shoot IDPA, and IPSC matches and use reloads which I load to similar velocities to my self-defense ammunition; this load is a 180gr FMJ-TC, over a charge of around 9.3gr of 800x.  this usually gets me around 1150 fps.  That’s a Power Factor of 207.  I do well in matches shooting this load, which has about the same Power Factor as a .45 ACP 200 gr+p loading. So I beg do differ that this round can’t be controlled. This round is quite controllable, but you need to practice, something we should all be doing anyway.