Gather round the campfire and tell me the story of the 10mm.


April 12, 2008, 03:08 AM
Hello all, besides shooting I as a student of History enjoy learning. There is one handgun caliber that has a very hazy past, and that (you already know by now if you read the title. ;)) is the 10mm.

Here is a sampling in no particular order of what I know or have heard about them:
a) I remember seeing old Colt Delta ads, and they just went away.
b) The FBI had some, but there was some reason they don't now.
c) Glock owners seem to be happy with their reliability.
d) They have impressive gelatin results, and yet they come off as a second class caliber, compared to .357, .45ACP, .44Mag etc.
e) Certain companies like Double Tap seem to be the champion of a robust 10mm load, where others are a bit anemic.

Thats all off the top of my head, feel free to address all or none of my ramblings. I'm not looking to own one, just curious.


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April 12, 2008, 03:26 AM
And why don't you want one?

It was and is...

- Sonny Crocket's Gun--The Legendary Bren-Ten!
- An Incredibly Versatile Auto-Pistol Load!
- True .357 Magnum Power--With 16-Shots On Tap (G20)!
- Flat-Flying, High Velocity Load, In Many Weights!
- Punch Paper!
- Drop Dear!
- Great Self-Defense Ballistics!
- 1608 fps, 767 ft/lbs, 135 gr DT Nosler!
- 1120 fps, 641 ft/lbs, 230 gr DT Hardcast!
- The Math Doesn't Lie!


April 12, 2008, 10:34 AM
The problem with the 10 mm round was not the guns chambered for it or the round itself (although the watered down loads caused disappointment), it was the timing.

Try to imagine a time when all of the current big bore "bruiser" handgun calibers did not exist (except mostly the .44 Magnum). Handgun shooters (not handgunners, which are a different breed altogether) thought they had a handful in the S&W .44 and .41, and the various .357s. In truth, those cartridges were awe inspiring to the average weekend warrior. Within duty circles, the focus was primarily on high capacity 9mm semi-autos (until the FBI shootout, anyway), and the general public sort of follows law enforcement/military as that is how many shooters are introduced to handguns. Along comes the 10 mm in a handgun somewhat before its time. It's a hot load, but the pistols are very much like handguns chambered for the rounds ordinary shooters are familiar with. Of course, the muzzle blast and recoil wasn't familiar, or fun. The average shooter (certainly not the people who post on these forums) doesn't like recoil or muzzle blast. The average shooter wants to feel in control of the pistol, not the other way around. Then, of course, there were no high capacity 10 mm semi-autos. The typical handgun shooter of the time was totally enamored of the large capacity magazines touted by law enforcement and promoted by Hollywood. With the minor exception of Don Johnson's character, no one on the silver screen was using a 10. The average shooter follows the fads. The 10 mm has never been a fad.

Today, with all the different handgun rounds far exceeding the 10 mm in ballistics, it seems rather puny by comparison. If you want power and punch, therefore, why choose the 10? Go for one of the new big-bore revolver cartridges. The 10 missed its window of opportunity.

Sadly, the 10 mm came along during a period of history when typical shooters weren't ready for it. It has only been in recent years that more shooters have recognized its compatibility for various uses. Still, it will never be popular because the average nimrod doesn't like the recoil and muzzle blast. I've spent 40 years hanging around ranges, teaching people to shoot, and just watching shooters, and I can tell you that most people would rather shoot a full size 9mm or a .38 in a K frame Smith, than a pistol they know is going to give their hand a jolt.

I own one 10 mm semi-auto. I shoot it a lot have decided that for an all around outdoorsman's handgun, its a pretty good choice (if you aren't willing to carry a revolver).

IMHO, of course...

April 12, 2008, 11:47 AM
The guns were an issue. When 10mm was briefly in vogue due to FBI adoption, a lot of different pistols appeared in the caliber. Various 1911s, Parkers, the Witness, Glock, Star, S&W, some carbines....I am probably forgetting a couple. Some guns did not hold up to the hotter loads. I suspect that had something to do with the ammo of the period not being optimal in terms of pressure. Regardless, 10mm developed a reputation for being hard on guns and as mentioned above being hard to shoot. Of course some of the guns built for 10mm were extremely tough, such as the 1006. But then you had a large, heavy, single stacked pistol. LE shooters in particular did not warm up to that. I recall when a local agency adopted the 10mm (following the FBI lead), many a deputy complained about the bulk of the Smith 10mm pistols and also recoil compared to their .38 revolvers. Quite a few had been shooting 9mm autos and hoped their agency would adopt that caliber, so the 10mm was DOA in their minds. Then along came the 40 S&W...

Of course those of us who love the round know that in the right gun with the right ammo, the 10mm is no bear to shoot. When loaded down to 40 ballistics it shoots much the same--better in some guns in my experience. Coupled with a light fast bullet, the recoil is not harsh and you can still get serious energy gains over other auto cartridges.

I suppose some of us more seasoned shooters were just more patient working out the way to best use a 10mm for defense or hunting. I just recently found a carry pistol in the caliber I am happy with for CCW use. Were I still wearing a badge, a G20 would likely have been on my side or perhaps a tuned 1911 in the caliber (agency permitting). I also have a Tanfoglio Limited that I just love shooting. I may eventually get around to running that in place of my 40 at some matches time permitting.

If you take time to get to know the cartridge, it has many things to offer. I cannot think of a more versatile round for an autoloader.


April 12, 2008, 12:09 PM
As I recall, the FBI was the driving force behind the 10mm following the Miami shootout fiasco.

So S&W built them the gun they thought they wanted, and Norma for one, was loading ammo that would curl your hair and jar your fillings loose.

But they soon found out many of the newly hired lady FBI agents couldn't reach the trigger on the big S&W, and most of the other agents didn't care for the size & weight of the guns either, in addition to the blast & recoil of the early loads.

So, they detuned the ammo.

Once they did that, they soon found they could get the same ballistics in a shorter case and smaller 9mm size guns.
Thus, the .40 S&W was born.

In the meantime, Colt gave up on the Delta Elite due to cracked frame problems they couldn't figure out how to cure with the early ammo specs.

Thus, the 10mm died on the vine in police circles, and the .40 S&W flat took over the LE market by storm.

Without a law enforcement market for it, there was no longer any demand, and it became just another niche civilian caliber like the .41 Magnum.

In fact the .41 Magnum followed a very similar path when it came out and was supposed to be the ultimate LO round.

Just too big & powerful, in big and powerful guns, for a modern & very diverse law enforcement community to handle.


April 12, 2008, 12:19 PM
If Ruger would chamber a P90 in 10, I'd try it. I think the round is too much for the 1911 platform. Colt had problems with the Delta. Most of the guns are BIG and not real carry friendly if they do hold up to the round's punishment. It's not the round I even THINK about for self defense for this reason, not when I can carry a 27 ounce .357 magnum, my SP101, or even my 30+ ounce 3" Taurus M66.

I see the 10 as the autoloader guy's outdoor/hiking gun. It's as powerful as a .357 out of a 6" barrel. It has plenty for anything you'd want outdoors short of Alaska and it's the only round that powerful that's fit into a halfway light, carryable package as with the G20. However, I'd rather carry a revolver in the field for its versatility. My .357 carry weighs about 34 ounces and can shoot .38 or .357 into sub 1" at 25 yards. Not many autoloaders that accurate. It can take small game or large with appropriate loads for either. My .45 Colt Blackhawk weighs a little more, but can push a 300 grain bullet to 1200 fps easily, sorta puts the 10 in the shade. :D

SO, I really don't have a need for the 10, frankly, until they can build one that weighs 14 ounces, packs 11 rounds, and fits in my pocket. I'll keep on carrying my 9 until then. They build subcompact .40s for the big bore crowd that CCWs that, frankly, is as effect as it needs to be for self defense. Kahr and Glock both have .40s in subcompacts. The G27 ain't much bulkier than the G26, though neither is quite a pocket gun, ain't a lot bigger.

For those that like autos in the outdoors, the 10 is THE round, though. I'm just not that into autos for such uses. But, I do think the 10 deserves more popularity. It'd be nice if there were a little bigger variety of guns chambered in the round.

April 12, 2008, 02:14 PM
It is certainly true that a few of the handguns chambered for this cartridge early on could not take the pressures. Mine is a Smith & Wesson 1066 and it is a substantial, strongly-built handgun, but it is as big as any 1911, as heavy (maybe heavier--I haven't checked), and the grip frame is larger, front to back, so it doesn't fit my hand as well. I have owned many types of revolvers over the years, and still do, but semi-autos always seemed to make more sense to me. Unfortunately, until the 10mm came along, there really was no way to get magnum handgun performance from a semi-auto. Of course, magnum handgun performance isn't necessary for most of the chores a handgun is called upon to perform. As for a lightweight, concealable 10 mm, I think the recoil would be major league uncomfortable and hard to control. Muzzle flash from full house loads would be blinding. The energy and penetration of a full house 10 mm load doesn't seem necessary in an anti-personnel role, unless the tactical scenario requires you to shoot through things in order to hit the adversary. Nevertheless, I cannot remember any tactical situation I was involved in that I would not have been perfectly comfortable packing my own 10 mm instead of the .45 ACP I routinely carried.

somewhat off topic...

All other things being equal, if I had to give up all the handguns I currently own and rely on just one to do everything, it would be a .357 Magnum revolver, possibly a Ruger Blackhawk, but more likely a Colt/Smith/Ruger DA.

April 12, 2008, 03:27 PM
This may not be THE story of the 10mm. And for those who don't like verbose posts, you may want to skip this one.

But for the rest sitting around the campfire waiting for a story, here is MY story of the 10mm.

I turn thirty-eight this July. The math seems to put me about 13 when the 10mm was born. And as an eager teenager, I was engrossed by the glossy photos of a revolutionary pistol in a revolutionary caliber: The Bren Ten in 10mm. It lept from the pages of various gun rags.

My parents were not what you would call gun people. They held hope that my infatuation with things that went bang would wane. And, so, there was little hope I would seen actually see, let alone get to shoot a Bren any time soon. But I knew one day I would be old enough to buy one.....

Anguish, horror, affliction, misery and torment. Dornaus & Dixon has failed, and my beloved 10mm is without a gun. Only 1500 Bren Tens were made before they failed. These were dark days when I realized my only hope for owning a gun in this great caliber may be a worn out relic for which ammo was scarce.

And then, the most unlikely of heroes...Colt. The Delta Elite was a fine looking gun. All the better since I had a huge attraction to all things designed by fellow Mormon John Moses Browning. I had visited the restoration/recreation of his father's workshop in Nauvoo, IL near my home. I was amazed at how many of his designs had withstood the test of time.

I became an evangelist of the Delta Elite and 10mm. I convinced a college roommate several years my senior to buy one. Five years from my first infection I finally had the joy or squeezing the trigger on a gun chambered in 10mm.

And the future seemed bright. The FBI was going to adopt the 10mm. Several new guns were due from Smith & Wesson in the caliber. And with the FBI behind it, I was sure it would soon be ahead of the .357 Magnum and 45 ACP in popularity as well as ballistics.

But it was not to be.

The problem was that many manufacturers were heavily invested in various 9mm handguns. Since the Army had adopted the Beretta it seemed the 'wonder-nines' were going to rule the world. It would be very expensive to engineer, test, tool and produce a gun platform for the high pressure 10mm. Especially when many saw the 10mm as a direct threat to recouping their costs on existing lines of 9mm platforms.

Further, the accountants the FBI turns into federal law enforcement (no disrespect) were having trouble adapting to the recoil and muzzle blast of the 10mm. This should have been foreseen. These were after all the same group who shot .38 Special loads in their 357 Magnum handguns.

The FBI had a solution for this. Turn down the power. The 10mm had an energy budget to spare, so instead of pushing a 180 grain bullet at 1400 fps, why not slow it down by 450 fps. A 180 gr moving 950 fps still gave equal or better soft tissue performance and better penetration.

However, this load offered a solution to manufacturers. A solution which Winchester and Smith & Wesson jumped on. Simply shorten the cartridge, cause you didn't need all that space to hold enough powder to make 1000 fps, meet the FBI specs and reach major in IPSC. Further, since the pressures were lower, you could thin the head some too. And magically, you have a cartridge which will fit in any wonder-nine frame.

This all occurred during my hiatus from gun magazines. At the age of 19 I began serving a two year mission for The Church of Jesus Christ of Latter-Day Saints. As a missionary I spent 160 hours a week either sleeping (8 hours each day) studying and grooming(3 hours each day) or actively proselyting. The remaining eight hours (Mondays from 9:30 AM to 5:30 PM) were preparation time spent doing laundry, shopping, getting hair cut, etc. During this time, I did not see my family, date, or spend any time reading gun magazines. Shooting a gun was expressly against the rules.

When I got back, I was amazed to hear about the new .40 caliber gun. Had my beloved 10mm been re-branded or re-labeled? Was it now sweeping the nation?

No, it was the sweetheart of the wonder-nine maker. The caliber they could pretty much just drop-in with only minor changes to their frames/slides.

Terre Haute, IN was a terrible place to shop for a gun in 1991. It may still be. That year the intersection of my available funds and the local sporting goods store resulted in a used Browning Hi-Power in 9mm.

Soon I was in Provo, UT for school. The gun market was better their. And I finally found one. A new in box Delta Elite 10mm. It rode home with me. I had arrived (or so I thought). It was joined by Glock 22 in .40 S&W, and a CZ-75 in 9mm. Along the way the Browning was sold, and I went through a Ruger in 45 ACP and a Smith 357 wheelgun. It seemed I was finally destined to spend Saturdays bringing up the lead and copper levels in Provo Canyon.

Then Cupid got a piece of me. And to woo this amazing girl the guns were sold. Even (gasp) the Delta Elite. The proceeds acquired a nice ring, and helped fund the wedding and honeymoon.

Years past.

About 18 months ago, I informed my wife that it was time. She was done being pregnant, after six beautiful children. My career as a software engineer was established. Time for me to return to my other love.

A little research showed great promise. I had loved everything about my CZ except the caliber. And a company in Italy made a CZ clone in 10mm. In fact, the Witness Elite Match even looked alot like a Bren Ten. And, it was rumored to be built like a tank.

I now have two Witness's in 10mm. A standard in wonder finish came first because a local dealer had one. Then a few months later an Elite Match was purchased on Gunbroker.

The future looks bright. There are a number of other options in 10mm, including Kimber, Dan Wesson, Wilson Combat, SVI, Fusion and Glock. Olympic Arms has an AR carbine in 10mm, and the Fortis remake of my beloved Bren Ten is on the horizon. And if you are willing to deal with a little extra cost, you can get conversions for Sig and H&K. I even saw a Beretta on YouTube running 10mm.

And there are many others who seem to love the caliber, members of the cult of 10. Bob Serva of Fusion Firearms, Mike McNett of Double Tap Ammunition, even, I am told, Ted Nugent who has hunted extensively with a Glock 20.

And that, is MY story of the 10mm. If you made it through my story, then you likely are a kindred spirit, dedicated to the cult of 10.

April 12, 2008, 03:40 PM
Copied from the entry on 10mm Auto

The 10mm Auto (10x25mm) is a cartridge for semi-automatic pistols, developed by ammunition manufacturer FFV Norma AB of Ĺmotfors, Sweden, and introduced in 1983 in the ill-fated Bren Ten pistol. Although it was selected by the FBI for use in the field, it proved too powerful to handle by many of its employees, and the pistols that chambered it were too large for some small-handed individuals. These issues led to the creation and eventual adoption by the FBI of a shortened version of the 10mm, known as the .40 Smith & Wesson, derisively known as .40 "Short & Weak" by 10mm aficionados. Although famous for its accuracy and stopping power, scarcity and high prices have made it a niche cartridge, with a small but enthusiastic group of supporters.

* 1 History
* 2 Performance
* 3 Usage
* 4 Synonyms
* 5 See also
* 6 References
* 7 External links

[edit] History

The 10mm Auto cartridge was championed by famous firearms expert Jeff Cooper. It was designed to be a medium velocity pistol cartridge with greater stopping power than the 9x19mm and better external ballistics (i.e., flatter trajectory, greater range) than the .45 ACP. When Norma designed the cartridge, at the behest of Dornaus & Dixon for their Bren Ten pistol (a strengthened variant of the CZ-75), they decided to increase the power over Cooper's original concept. The resulting cartridge, introduced in 1983, is very powerful, packing the flat trajectory and high energy of a magnum revolver cartridge into a relatively short, rimless cartridge for an automatic pistol.

Despite its supporters, it has generally failed to gain popularity because the full-powered loads have too much recoil and blast for many people's tolerances. Additionally, its reduced loads can be duplicated in smaller guns using the less expensive .40 S&W cartridge. In its lighter loadings it is an exact duplicate of the popular .40 S&W cartridge, in its medium loadings it can equal or exceed the performance of the .357 Magnum. It can exceed .45 ACP performance for equivalent bullet weights. With full-power loads and heavy bullets, it may be used as a deer, bear, or boar hunting cartridge.
1983 Bren Ten 10mm, SW 610 Classic 10mm
1983 Bren Ten 10mm, SW 610 Classic 10mm

The 10mm fires its bullet at high velocity, giving it a less-curved flight path and less drop or rise above point-of-aim compared to many other handgun cartridges, and thus is often described as "flat-shooting." Its outside diameter is also somewhat smaller than the .45 ACP and therefore offers the potential for greater capacity in a comparably-sized magazine. These characteristics also allow it to be used as a sub-machine gun cartridge, with H&K offering their MP5 platform in the cartridge.

The 10mm Auto has never had large-scale popularity; nonetheless many feel that it is an excellent cartridge. It earned a reputation for battering guns early on, largely because manufacturers attempted to simply rechamber a .45 ACP design for the 10mm Auto. The .45 ACP works at a much lower pressure and velocity, and the frame and slide designed to handle the .45 ACP cannot handle the greatly increased forces of a 10mm Auto without substantial strengthening. Later guns (most notably the Glock 20 and the Smith & Wesson 1006) were built around the 10mm and, if properly cared for, would work reliably for many years and thousands of rounds.
Colt 10mm Auto Delta Elite
Colt 10mm Auto Delta Elite

Another issue with early acceptance was the result of manufacturing problems with the Bren Ten; the contractor who was to manufacture the magazines had problems delivering them on time, and many early Bren Tens were shipped to dealers and customers without magazines. This, combined with the high price of the Bren Ten (MSRP in 1986 was US$500), caused the company to cease operations in 1986, after only three years of manufacture. Had not Colt made the rather surprising decision to bring out their Delta Elite pistol, a 10mm Auto version of the venerable Government Model, in 1987, the cartridge might have sunk into obsolescence, an obscure footnote in firearms history.

Thanks to media exposure (primarily in the television series Miami Vice), demand for the Bren Ten increased after production ceased. In the five years after production ceased, prices on the standard model rose to in excess of US$1400, and original Bren magazines were selling for over US$150 (Blue Book of Gun Values, S. P. Fjestad, 13th edition, 1992).

The FBI adopted the 10mm Auto round in the late 1980s along with the S&W model 1076 (a short barreled version of the 1026 with a frame-mounted decocker). The story goes that agents began having difficulty handling full-power 10mm loads. The FBI then submitted a requirement for a reduced-recoil loading. This later became known as the "10 Lite", or "10mm FBI" load. Pistol reliability problems increased with this lighter load and Smith and Wesson saw this as an invitation to create something new: a shortened version of the 10mm. This new round was called the .40 Smith and Wesson. The .40 S&W would function in a 9 mm-sized pistol; the advantage was that smaller-handed shooters could now have a 9 mm-sized gun with near-10mm performance. The .40 S&W has become the most popular handgun caliber among law enforcement agencies in the US, while the 10mm Auto has all but disappeared outside the hands of the hobbyist. Glock is one of the few manufacturers that still offer handguns in 10mm. Other manufacturers include makers of 1911 style pistols (Wilson Combat, Kimber and Dan Wesson all produce models) and the Italian company Tanfoglio (marketed in the US by EAA).

It must be noted however, that although .45 caliber pistols might not have been able to withstand the increased forces associated with the 10mm Auto, rechambering 9mm pistols for the new .40 S&W resulted in similar problems. While the .40 S&W round does not generate as much pressure as the 10mm, the cartridge is significantly shorter. As a consequence, when a .40 S&W cartridge is fired from a converted 9 mm pistol, the case might not be adequately supported by the chamber, which can result in breakage of the weapon. Newer handguns, specifically designed for the .40 S&W may not suffer from this problem, similar to later 10mm handguns being designed to handle the increased forces of that calibre. However, the .40 S&W remains to produce relatively high pressures compared to the relatively short length of the cartridge. This could be regarded as a "design-flaw" and is as such much harder to resolve than the increased forces of the 10mm. More information on this can be found under "Case failure reports" under the .40 S&W topic.[1]

Still, 10mm loyalists are likely to denigrate the .40 S&W as ".40 Short and Weak".[2][3] This is a bit of an overstatement, as the .40 S&W can come very close to 10mm performance in lighter bullet weights. Only with the heavier loads does the 10mm pull dramatically ahead. This is due in part to the 10mm Auto's higher maximum pressure (37,500 psi for 10mm; 35,000 for .40 S&W) and the larger case capacity, which allows the use of heavier bullets and more smokeless powder.

Since its introduction, the 10mm Auto has had a reputation for accuracy which the shorter cartridge seems unable to match. Recently, it has had a small resurgence in popularity, but ammunition can still be more expensive and harder to find than the common .40 S&W. Most avid 10mm shooters today are handloading, because the price of factory-loaded ammunition may go as high as US$37 for 25 rounds. Companies such as DoubleTap Ammunition have begun offering full power 10mm Auto loads in "common" price ranges.

[edit] Performance

The 10mm Auto falls between the .357 Magnum and the .41 Magnum in muzzle energy for popular loadings. With a good JHP bullet, these energy levels are sufficient to produce hydrostatic shock in living targets.[4][5][6][7][8][9] [10] For example, some commercial loadings are as follows: .357 Mag: 584 ft·lbf (792 J) for 125 gr @ 1450 ft/s; 10mm: 744 ft·lbf (1,009 J) for 165 gr @ 1425 ft/s;[11] .41 Mag: 788 ft·lbf (1,068 J) for 210 gr @ 1,300 ft/s (400 m/s). The 10mm load given is about maximum for SAAMI established pressure levels, while the .357 and especially the .41 Magnums are commonly handloaded to significantly higher levels than these samples. However, top 10mm loads will equal or exceed top .357 magnum loads from similar barrel lengths. Recoil energy of full-power loads is also comparable, being 9.4, 11.2, and 15.6 ft·lbf (21.2 J) respectively for these loads (computed using the same powder and weight of gun). The 10mm Auto may be used for deer or other medium game at short range. Ted Nugent is known for using a Glock 20 with an extended barrel when hunting wild boar.

Most 10mm handguns are not designed for long range shooting often desired in hunting; a few revolvers (using half-moon clips to adapt the cartridge) are made in this chambering, and offer another choice for hunters. Much currently manufactured 10mm ammunition is closer in performance to the "FBI load" than the full power 10mm; these still offer sufficient power for defense applications, yet their recoil is more comparable to the .45 ACP in similar guns. A few smaller companies offer full-power ammunition for this chambering. Due to the less common availability and higher than average cost of commercial ammunition, it is more a handloader's cartridge than most other popular auto pistol rounds. 10mm Auto ammunition should be available in a well stocked shooting retailer, though it is less likely to be stocked than more popular defensive calibers. Major ammunition companies do produce ammunition, and it is readily available through special order.

The 10mm Auto cartridge operates at very high pressure in comparison to other defensive pistol cartridges, such as the .38 Special or the .45 ACP. Its maximum average pressure of 37,500 psi is closely comparable to that of the .357 Magnum or the .44 Magnum, allowing it to develop higher velocities. Original loading was a 200 grain (13 g) bullet at 1200 ft/s (366 m/s), yielding 635 ft·lbf (861J) of kinetic energy at the muzzle. Today, Cor-Bon/Glaser lists a 180 gr "Hunter" loading of 1,320 ft/s (400 m/s) and 696 ft·lbf (943 J). This is nearly twice the energy of a .45 ACP. Double Tap Ammunition offers a 135 gr loading at 1,600 ft/s (490 m/s) producing 767 ft·lbf (1040 J) of energy, up to "10mm 230gr. WFNGC Hardcast" with Ballistics: 1120 ft/s (340 m/s) 641 ft·lbf (869 J). Such a wide range of bullet weights at high velocities demonstrate the 10mm's versatility. The 10mm is able to match or exceed both .357 Magnum and .45 ACP performance for given bullet weights, all in a 1911 or similar form factor.

[edit] Usage

The 10mm Auto is suitable for hunting medium-sized game at moderate ranges and is certainly more than adequate for defensive or tactical use; and one of the few true semiautomatic, rimless cartridges that is legal for hunting whitetail deer in many US states.

Today, the 10mm Auto cartridge is generally used to fend off medium-sized dangerous animals, as a high-powered defensive handgun, and for hunting, especially by those who prefer the flatter carry profile and higher cartridge capacity of an automatic pistol versus a magnum revolver. It is also an inherently accurate chambering,[citation needed] and one that makes major in IPSC even in lighter loadings.

Despite the FBI switching to the .40 S&W, there are still a number of law enforcement agencies that issue the 10mm including the Albuquerque N.M.P.D., the Anniston, Alabama P.D., and the Billings Montana P.D.

The 10mm's relatively flat trajectory has been regarded by some as moot in self-defense situations against human antagonists, given FBI statistics that indicate the average self-defense shooting takes place at 7 yards (21 ft) or less.[citation needed]

[edit] Synonyms

* 10mm Bren Ten
* 10mm Norma
* 10mm FBI
* 10x25mm
* The Centimeter (this name is also used to refer to a wildcat cartridge based on the 10mm Auto, which is trademarked by Pistol Dynamics[12])

April 12, 2008, 04:01 PM
Prior to the birth of the 10MM Auto a cartridge was created in the
1970s. Jeff Cooper had his hand in it being a regular columnist with
Guns & Ammo magazine. RCBS made the dies, Bar-Sto built
barrels to convert a Browning Hi Power to .40 G&A. The
.40 G&A was based on the .224 Weatherby Belted Magnum
rifle cartridge. THe cases were cut to approx. the length of the
BHP magazine dimensions then had to be reamed out, because
of the rifle brass being thicker toward the base. The bullets used
were the 180 gr. JSP Remington used for their .38-40 loading which
has a /401 bore. It headspaced on the Belt at the rear !0 shot
mag. capacity and propelled the 180 gr. bullets at 1050 FPS I think.
A wildcat round with very expensive brass.

A new kid on the block is Peter Pi's of CorBOn .400 CorBon
.45 ACP necked down for .401 bullets headspacing on the
25 degree shoulder. DUe to the length of the neck it loses
ground vs the 10MM Auto with 180- gr. and heavier bullets.
It does operate at lower pressures however, with SAAMI rating
it at the same CUP as .45 ACP +P.

S&W has added the 610 N-frame with 6 1/2" or 4" Bbl.
which fire the 10MM Auto or .40 S&W using full
moon clips. THe weight of the 610 is 46 oz for the longer
barreld model which should tame recoil.

April 12, 2008, 04:25 PM
Glock offers the Glock 29 model in 10mm, which is in the middle of the Sub Compact and Compact sizes of Glock models. It's smaller than a Compact, but bigger than a Sub Compact. If you want a 10mm for CCW, and don't want the bigger Glock 20, then try the Glock 29.

If in the wood,s I'd suggest against the DT 230 gr. 10mm, and go for the DT 200 gr. WFNGC Beartooth rounds, which fly in at 1300 fps, and 750 ft. lbs. energy (from a Glock 20... a little less from a Glock 29).

The 10mm can fly even faster than 1600 fps with 135 gr. but the legal limit to be loaded while selling them on the market as a factory manufacturer, is 1600ish fps. Same goes for the other DT 10mm rounds.

Keep in mind, DoubleTaps' 10mm tests are done with the stock Glock 20s' 4.6" barrel! Now imagine the 135 gr. in a 6" barrel? You'll be skimming 1730 to 1750ish FPS! With over 870ish ft. lbs. energy. Same with their 200 gr. Beartooth in 6" barrel: roughly 1420ish fps, with around 860ish ft. lbs. energy!

I've read people are reloading their 10mm rounds to fly in at 1830 fps. :O

It's an amazing cartridge, indeed! :)

Some brought up recoil: Look into "Dead Bang" recoil reduction system. I've read this system reduces recoil for much better rapid fire shots! The website says it's not really seen well if you're shooting one shot every 2-3 seconds, though.

Check it out! It might be the answer for those scared of "hot" 10mm rounds in their Glocks!

April 12, 2008, 07:42 PM
The comments here have been interesting, particularly all the posts on this thread (and elsewhere) concerning ballistics of the 10 mm and so forth. It's actually gratifying to see such interest in a supposedly "dead" cartridge. What I would like to see are comments regarding the practical use of the 10 mm. The academic discussion is wonderful, but largely theoretical. Does anyone have any real-world experience with this cartridge, either in the hunting field or in a tactical application? Perhaps if shooters could read something that demonstrates this round's useful application to real life situations, they might be convinced to pay more attention to it.

April 12, 2008, 08:49 PM
Count me in a tremendous fan of the 10mmm for a woods gun. I have no intention of carrying anything else to hunt with as long as we're just talking about mule deer and smaller. I also wouldn't hesitate to use one on a cow elk under the right conditions.

I was bound and determined to get my deer again last year with my G20. This will make 2 with this gun. I passed on several within rifle range in hopes of getting within range with my pistola. I had planned to hold out until the last evening and then go get one with a rifle if I couldn't make a pistol shot. This unfortunate little fork-horn wandered a little too close. 180 gr. Hornady XTP traveling at 1300 fps at 112 yards through both lungs. He walked around for a minute then went down. I was sure I had made a good shot but I was still approaching him slowly. A dang pheasant jumped right out from under me and scared me and the deer both. He jumped up and started running and, as sure as I was that my shot was good, I didn't want him to get into some thick brush so I shot again as he was running at about 25 yards. The 2nd shot entered his left ear and came out his left eye. Sure enough, that anchored him

Second shot...

Here's what the lungs looked like. Very little expansion.

Here's a 50 yard target. The group on the left was before the final sight adjustment.

And here's the gun I shot it with...

April 12, 2008, 09:23 PM
I've seen two guys down here in Texas who replaced the standard Glock 20 barrel with a factory Glock 6 inch barrel and it is supposed to have the same ballistics as a 41 magnum. They were both used to hog hunt.

April 12, 2008, 10:51 PM
Personally, I think the 10mm can handle any midsized game on the N American Continent. I took a South Ga Wild Hog easily with a G20 a few years back. He weighed out at 178 pds and one shot took him though the shoulder, split his heart and passed through both lungs. He was dead before he realized it and laid down 10 steps later.

It is perfect for defense from two legged critters and most 4 legged. It might not be the best for Grizzles... but a .44 mag aint going to be foolproof either. But it would be better then throwing rocks at him. IMO I would think pumping 16 200gr DT Beartooths into a big bruin would make him slow down at least 16 seconds before he ate me.

6 rds of .44 mag 250gr DT Beartooths would only slow him down for a 6 seconds.

I need that extra 10 seconds.

April 13, 2008, 01:38 AM
Love the stories! Its nice to hear experienced with a particular gun or caliber without a vs. debate. Not that a healthy vs. can't be good, but sometimes someones dog gets insulted. ;)


Travis McGee
April 13, 2008, 08:41 AM
Does anybody know if the FBI is still using their 10mm MP5/10 subguns?

April 13, 2008, 09:05 AM
they got rid of those along time ago...

April 13, 2008, 12:03 PM
Ted Nugent hunts with his Glock 20 in Africa all the time. I've read he has taken down 1000+ lb. game over there with his Glock 20.

He even made a song "Kiss My Glock" he loves it so much. Come on now, guys... Ted has probably fired more guns than all of us put together, yet he still goes for the Glock 20 for hunting? That says something, I'd imagine! :D

April 13, 2008, 02:03 PM

^ So what you are saying Northalius is if this ^ guy is standing behind the counter, you are buying a Glock 20 from him? I would! :D


P.S. Love to pull that pic out when the Nuge is brought up, especially when archery and Self defense are in the same thread. :)

Bob R
April 13, 2008, 03:07 PM
Does anybody know if the FBI is still using their 10mm MP5/10 subguns?

There is an FBI agent that posts on the S&W board, and he still has his MP5/10that the FBI issued to him.


April 13, 2008, 03:25 PM
I don't have any pics to share, but I've taken a number of West Texas whitetails with my 10 mm which has a four inch barrel--as measured from the back of the chamber. Most shots have been taken within normal handgun ranges up to 50 yards or so, but one memorable shot was at a little over 80 yards. I never shoot unless the animal is standing broadside, and mostly I aim for a lung shot. I shoot the Winchester 175 gr Silvertip exclusively, but lighter bullets would probably work as well because the whitetails in my area average only 100 lbs or so. I've never lost a deer after shooting it with this pistol, and never had one run more than about thirty steps. Expansion of the Silvertip is good as evidenced by internal damage and size of the exit wound--I've yet to recover a bullet.

Though I like my 10 mm, and have had a lot of success with it, under the circumstances which I hunt whitetails (on foot in brush) most shots are within 5 to 20 yards. Accordingly, all that power seems almost surperfluous. A .22 rimfire will do as well. Nevertheless, the 10 mm makes an outstanding outdoorsman's handgun, for the shooter (like me) who prefers a semi-auto. If Smith & Wesson would reissue the 10 series autos with a 5 or 5.5 inch barrel and a few other amenities, advertise it as the "New" Outdoorsman, they might be surprised at how many of us would buy one.

Travis McGee
April 13, 2008, 09:23 PM
Thanks Bob R. If I was an FBI man, I'd sure feel well armed with a Glock 20 and an MP5/10!

April 13, 2008, 09:27 PM
Love the cartridge. never shot a 1911 in 10mm. Have the
Glock, but no fire for that platform with the mighty 10.

Have owned the Witness 10 for about 8 years now.
Think it is the perfect 10mm for me. Stoked with Double Tap
of course. 165 or 180 grain Gold Dots. Don't have any Grizzly
around here, or it would be the 200 gr. DTs.

Bob R
April 13, 2008, 09:36 PM

His duty gun is a P220.45 that has been grandfathered in for him to use.

He says they use a 190gr bullet in the MP5/10.


April 13, 2008, 09:45 PM
Well I picked up a G20 at an auction for 300 bucks and at first I thought well if anything I can just sell it, but I really like it, I plan on using it for CCW and I am going to get a G29. 10mm is just fun to shoot and its a great caliber.

April 13, 2008, 10:03 PM
The problem, as I see it, with using an auto in the field as a primary hunting gun is accuracy. Revolvers, good ones with scopes, can put five magnum rounds into 4 inches all day long at 100 yards. Few autos of a locked breach design can do that. Scoping 'em is a pain anyway. So, they are quite the short range propositions, probably 50 yards and in. Well, that's fine, though, if you're looking for that accuracy level and shooting iron sights anyway. The G20 is LIKELY to be the most consistently accurate just in my experience, but then, I have no experience at all with the Witness and cannot comment on that one. I have experience with a couple of 1911s, the Delta (good for 2.5" at 25 yards, the one I played with and knew the guy that owned it) and an AMT jamamatic Javelina (steer clear of this one) that didn't do any better than the Delta. I'd like a little better accuracy than that for 50 yard hunting, but I guess it'd get the job done.

My favorite handguns will put a cylinder full into an inch at 25 yards and will, even with iron sights, be able to hit minute of pie plate, normally well under 8 inches, at 100 yards. A good scope would get those groups under 4". I generally keep my shots under 75 yards with iron sights on any handgun. 100 yards is pushing it with irons and my old eyes. I have a scoped contender in .30-30 if I really wanna get serious about handgun hunting accuracy and power. It lays down more power at 200 yards, almost 1000 ft lbs, than a 10 at the muzzle and shoots 3" groups at 200 yards. But, when I want a challenge, I'll grab a Blackhawk with iron sights. :D I've taken two deer with a .357 Blackhawk and a 158 grain SWC at 760 ft lbs, about 10mm territory. It produced full penetration at slightly over 50 yards and gave a nice wound channel. Neither deer went very far. If the .357 can do that, I see no reason the 10 can't do even more, considering bore diameter and bullet weight. Thing is, you gotta hit it in the right place. If you can do that, be assured that the caliber of the gun is plenty for the job of hunting mid sized game. It is the ONLY round in a decently sized autoloading handgun (even my contender is light and small compared to a Desert Eagle) that should be called a magnum.

April 14, 2008, 12:00 AM
That G20 back in post #13 seemed to do OK in the accuracy department...

April 14, 2008, 10:52 AM
If you really want a revolver in 10, check out the Smith & Wesson 610. This is not a direction I would take, as I can think of a lot of other calibers available in similar sized revolvers that would be preferable for hunting/long range shooting to a 10.

Or, to be honest, if I have to take a shot at 200 yards, I will break out my 700P in 300 Win Mag. 200, 300, 500, 700, 1000 yards, the gun can do it. (My skills may be questionable.)

This gets to the crux of what is wrong and right with the 10mm. It is perceived (right or wrong) as being a little too stout for defense, because of concerns about both over-penetration and ability to shoot accurately. It is, ballistically, a good choice for game up to white-tail deer. However, the auto-loader is NOT a conventional hunting platform, and for similar dollars, a revolver is usually more accurate.

The 10mm then becomes the practical man's handgun cartridge. I can carry 15+1 of 10mm for self/home defense. I can hunt small-medium game with 10mm. I can plink with it economically (reoad). And the money I save by not buying two or three or four or more different guns for different things will pay for lots more time at the range.

April 14, 2008, 12:02 PM
If you really want a revolver in 10, check out the Smith & Wesson 610. This is not a direction I would take, as I can think of a lot of other calibers available in similar sized revolvers that would be preferable for hunting/long range shooting to a 10.
A 10mm in a revolver would defeat the purpose if you're trying to keep your velocity at acceptable levels. The barrel/cylinder gap would lose enough pressure to put your 10mm at or below .40 S&W velocities. Especially with factory loads.
Yes, I can think of a few revolver rounds that may be preferable to the 10mm but when you can push a 180 grain bullet at 1300 fps, that puts it right up with many of the revolvers and surpasses quite a few of them.

It is perceived (right or wrong) as being a little too stout for defense, because of concerns about both over-penetration and ability to shoot accurately.
Over-penetration I can buy but I have never heard a single complaint about the 10mm not being accurate enough for defense.

It is, ballistically, a good choice for game up to white-tail deer. However, the auto-loader is NOT a conventional hunting platform, and for similar dollars, a revolver is usually more accurate.
Up to white-tail deer? You're kidding, right? The majority of the white-tails in this country are not much bigger than coyotes. You can kill most white-tails cleanly with a Benjamin air-rifle.
The handgun is not a traditional hunting platform period so I don't think the style that you use really has a classification. Handgun hunting overall is not that old and, not counting single-shots, revolvers do probably outnumber semi-autos in the hunting field but that doesn't make them "traditional". There are more and more semi-autos going out every year and for me, that's about the only thing I take anymore.

BattleChimp Potemkin
April 14, 2008, 12:19 PM
We had a FBI agent arrive at our range once (with friends, to show them shooting). She was a wonderful lady. We let me run a magazine through the MP5/10. Amazing weapon! Absolutely useless on full auto, however, the 2 round burst really puts it in my mind: Dont mess with these folks. The two round burst puts the round roughly within an inch of one another. Scary thought.

Her service pistol was a Glock (compact model, too many darn numbers) in 10mm, which no one at our range liked (too much bang and recoil actually hurt!).

Needless to say, I was enchanted with her 10mm wonderweapon :D and would love to get my hands on a 10mm pistol (the handloading alone would be wonderfully fun!).

April 14, 2008, 12:30 PM
I would really like to see a resurgence of the 10MM. It is a great caliber. If we can have a .460 and .500 why not just bring the 10mm back. If more platforms are developed for it, more ammo will be made for it and cost will fall in line.

I encourage all the 10mm fans to write to S&W, Ruger, Sig, Springfield, HK, and any other manufacturer and request tehy develop a 10MM. I do this all the time. It takes only a few minutes to to wrote an e-mail. If they get enough mail, email, calls, we may see a new 10MM come out.

YOu can be sure we won't if we don't ask for it.

April 14, 2008, 03:21 PM

We seem to be agreed with regard to revolvers. Yes, there is an option, the Smith 610, and no, neither of us would apparently buy one.

I didn't mean to imply the 10mm was inherently inaccurate. The ability to which I refer is that of the shooter, not the gun or cartridge. This is due to flinch that is common as recoil, report and muzzle blast increase.

There are a number of complaints of this type. The largest was probably the FBI, which downloaded the 10mm to overcome this issue. This, of course, lead to the creation of the 40S&W.

By the same token, neither is over penetration inherent to the cartridge, but to bullet selection at a given velocity. This is best shown by the FN 5.7X28 and it's ability to defeat body armor at approximately half the energy level of the 10mm.

Game and hunting weapons:
I am no hunter and was here merely regurgitating the opinions of those I respect (and that make sense to me). Yes, I am aware a properly placed shot from almost anything will do under the right conditions. I have put down many a bovine with a 22lr in the barn yard.

I grew up in Indiana. White tail is the about the largest game regularly hunted in that area, and 10mm would be a great option (if legal). I do not see people in the mountain west where I now live using the 10mm for 75-300 yard shots that I am told are common on mule deer and elk.

I would agree that mule deer are about the largest game animal commonly hunted in North America that could be classified as medium game. However, their typical habitat makes hunting them with a 10mm difficult proposition.

Incidentally, whitetail deer are on average more than twice the size of a coyote. The largest coyote ( on record (75 lbs.) is still 15 lbs short of the low average for a whitetail doe ( (90 lbs.).

I did not use the word traditional in my post, although you also took exception to it's use. The word I did use was conventional. It was an adjective modifying hunting platform. While handguns may not yet be traditional, there certainly is an established convention to use them as a hunting platform and for their use within that platform. Within the handgun hunting platform the conventional handgun is either a single-shot weapon or a revolver. Per Chuck Hawks "Semi-automatic hunting pistols are few and far between." (

Perhaps I have mis-interpreted the tone of your post, but it certainly felt as if I were being called out to defend my statements. If I have mis-interpreted your tone, then clearly we are in agreement, despite my perception to the contrary.

The 10mm is a great cartridge, that gets overlooked all to often, and is improperly maligned. It is presently and for the near future the ONLY large caliber I plan to own in a handgun. Were I to get involved with handgun hunting, I would almost certainly choose the EAA Witness Hunter in 10mm as my weapon.

April 14, 2008, 05:15 PM
I think, for the most part, that we are in agreement except for the "traditional" part. I pasted your quote right above my statement so, even though I used the wrong word, it should be apparent what I was talking about.

I still think the 10mm is a little horsey for human targets as far as penetration goes. I DO agree that if you are exceptional particular about the kind of bullet that you use that you can alleviate some or all of the over-penetration issue. But to me, that's unnecessary and, in my mind, makes the 10 a little too much. If a 180 gr. Hornady XTP will completely penetrate a mule deer at over 100 yards, I can't see it doing otherwise on a human at 10 feet.

April 15, 2008, 02:48 AM
i suppose this has nothing to do with the question but ive never said it before
but i think the size and proportios of the 10mm is one of the best looking pistol rounds there is

April 17, 2008, 03:09 PM
I've loaded 135 Rainier plated bullets to over 1700 fps out of a 6" Glock 20. Penetrated to 22" in water and expanded to over .6"

That works out to about 14" in ballistic gel. You should see what this round does to a water filled milk jug!! Blew the top clear off and laid the bottom flat on the ground in 3 sections.

So that gives an explosive impact and no over-penetration.

I do carry this weapon/round when I'm not carrying my 2" Ruger SP101 357.

Mike G.

August 24, 2013, 03:51 PM
Zombie Thread time!!!!

I recall reading somewhere (probably on this forum) that what messed up the Bren Ten was the magazine availability problem. Of course this is info from the internet so it is not guaranteed and it's subjective since it's nearly impossible to track down the folks from Bren to get the real, entire story from then.

Here goes what I remember reading....

Miami Vice and Don Johnson had the USA firearms community wanting the Bren Ten badly! Bren had the magazines made from a factory in Italy. Then a nutjob tries to assassinate the Pope. Then Italy puts on hold all firearms related exports from Italy for months (possibly up to 14-19 months). In incredibly bad timing this included the Bren Ten Magazines for their pistol which had already shipped a few hundred or so pistols. The completed Bren Ten magazines sit in a warehouse near the port in Italy for months and months while the ban runs. And who knows if the magazines were properly sealed against moisture and sea air infiltrating the shipping container and boxes inside. The ultimate Aww $#*! situation for Bren and their customers.

The long, long wait made for many, many cancelled orders which simply ruined the company and the pistol which likely would have sold well. Therefore, the 10mm was set back a decade or so. Plus, the FBI deciding it had "too much recoil" and creating the 40 S&W to buy in large quantities for the FBI and other law enforcement instead.

Again, this is from memory, so I am likely off on some details. But it does sound likely and logical. If I'm wrong, then I'm wrong, and oops. Business with suppliers is often complicated.

I think it was a "perfect storm" of bad luck, bad timing, and bulk buyers (military, police, FBI, etc..) going with other calibers like 40 S&W that set back the 10mm in popularity several years.


August 24, 2013, 04:42 PM
I've always been a fan of the 10mm and would like to own one some day. Don't have anything much else to add than that but I did see another very interesting cartridge the other day called the .40 super. Here are the specs compared to the 10mm.

Technical Information:
Caliber: 10mm Auto
Bullet Weight: 135 Grains
Bullet Style: Nosler Jacketed Hollow Point
Case Type: Brass

Ballistics Information:
Muzzle Velocity: 1600 fps
Muzzle Energy: 767 ft. lbs.

Technical Information:
Caliber: 40 Super
Bullet Weight: 135 Grains
Bullet Style: Nosler Jacketed Hollow Point
Case Type: Brass

Ballistics Information:
Muzzle Velocity: 1775 fps
Muzzle Energy: 945 ft. lbs.

Only down side is it's a bottle necked cartridge, anyone own both of these cals?

August 24, 2013, 08:41 PM
Might not starting a new thread seem more productive than resurrecting a 5 year old one

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