TAFFIN TESTS: The 10 MM

Sixguns.com ^ | 2000 | John Taffin

[45Auto]

The modern beginnings of the 10MM go back to the early 1970's with the creation of the .40 G&A. At the time, there were three semi-auto cartridges of any serious consequences available, the 9MM, the .38 Super, and the .45 ACP. The idea was to come up with a cartridge that combined the best qualities of the 9MM and .45 ACP. With the creation of the new .40 semi-auto cartridge, the statement was made that "...the .40 caliber was chosen because it can be shown mathematically that it takes about this size projectile to provide the cross-sectional area to achieve adequate stopping power at reasonable pistol velocities."

There are any number of experts, men who have first hand knowledge of bullet performance in both hunting and defensive situations, who would dispute that there is any such thing as stopping power. Penetration combined with hitting vital areas seem to be much more important and the .40 G&A would certainly offer excellent penetration capabilities by combining the speed of the 9MM with the bullet weight of the .45 ACP. The larger the caliber, the better the chance of hitting vital areas. The .40, while not as good as the .45 in this respect, is certainly better than the 9mm, speaking strictly from the standpoint of the cross sectional area offered by each cartridge.

The .40 G&A was wildcatted using cut down .224 Weatherby brass and 180 grain .38-40 bullets. Chambered in a Browning Hi-Power, maximum velocities were right at 1250 feet per second. The .40 G&A went nowhere but it opened the doors for the 10MM.

Now enters the Bren Ten. In 1984, Jeff Cooper put his stamp of approval on a new semi-automatic from Dornaus & Dixon, the offspring combining some of the best features of the Czech made CZ-75 9mm with the distinct advantage of a larger hole in the barrel. The amazing thing is that Chairman Jeff took to heart a semi-auto that was not chambered in .45 ACP and was a double action semi-automatic. The new caliber was the 10mm, and the new semi-auto, while a double action, could be carried cocked-and-locked.

Cooper named the new handgun the Bren Ten, BR for the BRNO factory in Czechoslovakia and EN for the British Enfield factory. Bren Ten made a catchy name for the new 10mm. Unfortunately, the name still exists and the Bren Ten itself is no more. By 1987, Dornaus & Dixon had gone into bankruptcy.

The gun died, but the cartridge did not. Colt rescued it by chambering the Government Model, renamed the Delta Elite, and 10mm handguns have been available from Springfield Armory, IAI, LAR, Thompson/Center, Glock, Smith & Wesson with the 1006 and 1016. I can think of no other instance in history whereby the original handgun died so quickly, and yet the cartridge lived on in so many persuasions most of which are now also gone.

Loading the 10mm proved to be sufficiently easy with the use of RCBS Carbide dies. I always like to leave about one-sixteenth of an inch of the shoulder of any semi-auto bullet exposed. This works with some bullets in the Colt 10mm but loads for the Javelina must be seated with the shoulder flush with the case mouth.

Four jacketed bullets were shot extensively in the Colt and Javelina 10mms. Those bullets were Sierra's 150 and 180 grain jacketed hollow cavities, Speer's 190 FMJ, and Hornady's 200 grain FMJ. A fifth jacketed bullet, Hornady's 170 grain jacketed hollow point was used in the Javelina alone.

The 10mm proves to be quite fussy about the jacketed bullets and load combinations it is being fed. The Speer 190 would not group at all with either of the Colts with any of the loads tried. Switching to the Javelina, the same Speer 190 would shoot into less than two inches with the right load. I called Speer and they related that they too had had problems in the Colt Delta Elite and others have related that the Delta Elite is no great shakes accuracy-wise with any loads tried. Both Colt Delta Elites I used for testing the 10mm had been worked over with slide tightening, trigger jobs, etc, but had stock barrels.

Many jacketed loads proved to be exceptionally accurate in the Colt Delta Elites and the Javelina with many loads grouping under two inches or less at 25 yards when fired using the Outer's Pistol Perch as a rest. A sandbag is placed in the barrel notch of the perch and another is placed on the platform that serves as a hand rest. This proved to be the best way of using the Pistol Perch for accuracy testing.

Some excellent loads surfaced as the testing progressed. With jacketed bullets in the 180 to 200 grain category, 10.5 grains of AA#7 gave velocities in the 1100+ fps range and consistently grouped in two inches or less with both the Delta Elites and the Javelina. This same load gave the same excellent results with the RCBS #10mm-200 cast bullet in the Colt Delta Elites. Groups ran in the one and one-half inch range with velocities at 1200 feet per second. Switching to the Javelina, 11.0 grains of AA#7 gives 1281 feet per second and groups right at one-inch. An excellent practice or competition load for the 10mm with the RCBS cast bullet proved to be 5.5 grains of WW231. This load goes 1000 fps from the five-inch barrel of the Delta Elite and 1075 fps from the seven-inch barrel of the Javelina. Accuracy is so good, I would search no more. This load makes major with plenty to spare, is easy to handle and consistently groups under one and one-half inches. For a lighter cast bullet, I use the Bull-X 175 grain semi-wadcutter. The same 5.5 grains of WW231 gives velocities of 1050 in the Delta Elites and 1100 in the Javelina. Easy shooting and easily makes major for action shooting competition.

Is the 10mm a hunting pistol? With qualifications, yes it is . The qualifications are the proper ammunition and especially discretion. Pushed to the limit, the 10mm is better than the .357 Magnum but still quite a bit below the .41 Magnum. I have been using the 170 Hornady Jacketed Hollow Point and have developed a warm load of 13.0 grains of AA#7 for 1374 feet per second from the seven-inch Javelina. This should do the job on small deer without any problem. This load should also be worked up to carefully starting at around 11.0 grains.

[Jack Black]

The 10mm is a nice round. Unfortunately it's dying out there. Other than the Glock you can't really buy a gun that is chambered for it. Smith discontinued all their pistols (but have one revolver for it). Colt doesn't make the Delta anymore. Kimber and Springfield don't chamber for it either. Sig - Nope. CZ - Czilch. HK - Hardly. Ruger - Nada. Supposedly there is an Italian one but they are scarce. (Tanfaglio imported by EAA) you can get but I had one on order for six months and my shop couldn't find one)

So it might be a great round, but your gun choices are limited. You can buy a Kimber .40 and send it to a high end smith and get a conversion.

Given that I bought another .45. Yeah, I like the ten but it's like handloading wildcats... just too weird for the additional spunk the round has.

If it revives and more guns get chambered and more ammo makers start making ammo I'd consider getting one...

[Noumenon]

I like my Glock mod 20. It handles well and allows me to put a lot of hard-hitting rounds into a small area very quickly. I was fortunate enough to buy it and many 15 round mags when the mags weren't insanely expensive.

The mod 20 is my preferred carry when I'm not out with the missus. Then it's matched SIG 229s in .40.

[Travis McGee]

Anybody know if the FBI is still using their 10mm H&K MP-5s?

They bought a couple thousand on a one time production run a few years ago.

I work this into the plot of my book, when 10mm brass is found near a shooting and it leads back to the feds.

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Seems like 10mm's okay ballistically, but is it so superior to the .45? If it's not, why to to all the added hassle of dealing with an oddball round?

Of course, if oddball rounds are your thing, more power to you.

I think .357, 9mm, .40S&W, .44 special, .44magnum, and .45 all provide shooters with plenty of defensive options, and there are hundreds of guns chambered for them.

The jury is still out on 10mm and .357SIG. Time will tell if they have earned a permanent niche.

[Travis McGee]

See 23 please. Know anything about the 10mm H&K MP-5 "FBI Special Edition?"

[Squantos]

Do not have a 10MM Travis !.........hard to believe huh, but true. Don't have one, don't need one. Of course need was never a requirement for a gun'o'the month club purchase.

Know lots of folks who use it to hunt with in performance center S&W's N frames.. Good whitetail deer , wild pig caliber I'm told.

Not sure if FiBi's or BatFag'eeeeee's are toting em .

Stay Safe !

[Travis McGee]

Heckler & Koch MP5/40 and MP5/10

The MP5/40 and MP5/10 are product improved variants of the 9mm MP5 chambered for the more powerful .40 S&W and 10mm Auto cartridges. Although the operation and functioning principles of the MP5/40 and MP5/10 are identical to the 9mm MP5, several user inspired improvements have been incorporated into the design, including a new bolt catch device that holds the bolt group rearward after the magazine is empty. Depressing the bolt catch releases the bolt to chamber the first round of a loaded magazine.New lightweight synthetic magazines are durable and ensure reliable feeding under the most extreme conditions. Like all MP5s, the MP5/40 and MP5/10 can be disassembled without tools for cleaning and maintenance. The firepower, penetration, and hard-hitting potential of a 10mm MP5 is greater than a .45 ACP Thompson submachine gun. At any range, the projectile fired from a 10mm MP5 has nearly twice the energy of a comparable 9mm, .40 S&W, or .45 ACP cartridge. In 1994, the US Federal Bureau of Investigation (FBI) adopted the MP5/10 as their new submachine gun.

[Squantos]

Gotta remember the field SWAT & HRT weenies were carrying M4's in Waco and I believe the local FiBi's even popped the Eagle Scout recently with an M4.............have to wonder who is still actually packin the MP-10's..............probably a feild agents trunk tewl for robberies ect ect.

Stay Safe !

[Squantos]

Nice rig......Good one caliber choice's....Stay Safe !

[Travis McGee]

They are probably using all kinds of guns. Just like everywhere, folks get a new slice of budget, and go shopping for bigger better faster more.

That said, in my plot it will work to have the ATF bad guys use the MP-5/10. They are in a small special unit which could probably scoop up some unused old FBI MP-5/10s.

Since I am inventing the special unit, I can give them any damn guns I want. And since lots of MP-5/10s are in the federal system, they could grab 30 or 40 easily, if most of the fibbies have moved on to M-4s with all the bells and whistles attached.

Basically, it's a convenient plot hook to find 10mm brass, which leads to the feds.

[Travis McGee]

What kind of 100 yard groups can your Oly CAR97-10 get?

Do you reload 10mm? Do you ever shoot subsonic 10mm, and if so, what kind of bullet and powder combos would you suggest?

In my book, bad guys use a suppressed MP-5/10. It's not clear if they used subsonic loads or not, and not critical either way as written. I'm just curious.

[NordicG3K]

One of the interesting things about the MP5/10 is that it used two different weight bolt carriers. Designated "high impulse" and "low impulse" the low impulse units were to be used with ammo that rated 1100fps and slower (with 180gn bullets I believe). For ammo hotter than that the high impulse unit was to be used. As I understand it HK had difficulty adapting the MP5 roller-locking design to work with such a wide power range. Make it 100% reliable with the "FBI Lite" fodder and the gun beats itself up. Focus on the full-power loads and you get reliablity problems with the lite stuff. Answer - two different bolt carriers.

There are a lot of excellent self defense cartridges out there and bullet design technology has closed the performance gap between many of them. What makes the 10mm special is that it can do so many jobs exceedingly well. With "FBI Lite" style loads its a great plinking gun. Move up to something like Winchester's 175gn Silvertip or Hornady's 155gn XTP and you have an excellent CCW gun/cartridge combo. Stoke your favorite 10mm with some of TAC's 200gn XTPs at 1250fps and you're ready to hunt deer and pigs. The 10mm is just capable of doing more jobs than most other cartridges.

Current production 10mms include the following:

Glock 20, 20C & 29
S&W 610 (currently in 4" format)
EAA Witness full-size and compact
Dan Wesson Patriot and Razorback (1911 guns)

Other commonly found 10mms include:

Colt Delta Elite
S&W 1006/1066/1026/1076/1046/1086

Also, converting a .40 S&W 1911 to 10mm requires nothing more than a barrel swap and a recoil spring upgrade. I had a Scheumann .400 Ultimatch bull barrel chambered in 10mm fitted to my Paraordnance P16.40 and stepped up to a Wolff 23lb recoil spring and it runs like a champ!

One other note, there are rumors that Kimber will be releasing a 10mm later this summer!

[NordicG3K]

Travis, my "range load" is a lead 180gn LTC at about 1040fps out of my 5" guns. Out of the Oly carbine it feels like I'm shooting a .22 rimfire. I rarely shoot out to 100 yards with it, but I can get easy 2-3" groups from 50 to 75 yards which is the normal distance I shoot the gun at. I'm working on a 200gn JTC load with a healthy dose of Blue Dot, but haven't had a chance to chrono my latest batch yet. Popular powders for full-power 10mm loads are Blue Dot, AA#7 & #9 and 800x. If you're looking for some serious factory loads I highly recommend Texas Ammunition Company. Their 135gn load is listed at 1450fps, the 165gn load at 1350fps and the 200gn load at 1250fps. These loads are pushing close to 700ftlbs out of a 5" barrel. I've been using the Winchester Silvertips in my S&W 1086 for concealed carry, but might switch to the TAC 165gn JHP. I have to try out some more of the TAC ammo before I decide.

[Lurker]

Need anymore .40 brass?

Let me know.

L

[yarddog]

If anyone still makes copies of the M1 carbine it would seem a natural for the 10mm.

[archy]

If anyone still makes copies of the M1 carbine it would seem a natural for the 10mm.

That's been done, as has the .45 Winchester Magnum in a reworked M1 carbine, though recoil from that load eventually shatters the wood stocks. But another problem is that the wider cartridges reduce the magazine capacity to six or seven rounds when using the carbine's original 15-round magazine, and feeding reliability can be compromised if the curved 30-round mag is used.

But there's an Israeli bullpup stock arangement now available for the G.I. carbine, as the carbine is a polular weapon still widely used by civilian police reservists there. The real answer would be a light carbine specifically designed around the cartridge, a very real possibility if the *assault wweapons ban* sunsets at the end of next year.

And wouldn't a Calico 9mm M950-style pistol/carbine in 10mm with a 50-round magazine be interesting...?

[Travis McGee]

Great info, thanks! I had not heard about the two bolt carriers, it makes sense. But one had better be careful which ammo one is using! One way the action won't feed reliably, but the other way, the gun may self-destruct.

[archy]

Seems like 10mm's okay ballistically, but is it so superior to the .45?

At 25 meters, the 10mm bullet [180] is travelling faster than a .45 round at the muzzle. Velocity is not the whole story, of course, but the 10mm is certainly an interesting development, and like the .45 ACP, as nicely usable in revolvers as in semiautos.

Among its shortcomings is that it can be brutal to machinery adapted to it rather than purpose-designed for it, as per the Colt Delta Ten. But it's interesting too for it's usability in handgun-carbine or handgun-SMG combinations.

And back when the Norma factory loadings appeared, I ran across a AKM kalishnikov adapted to the 10mm cartridge, interesting but I'm not certain as to the exact requirements the user had in mind for the one-off custom work, with a very nice Lothar Walther target barrel pretty much wasted in an AKM action. But the 7,62x39mm AK cartridge necked out to 10mm also has interesting possibilities....

-archy-/-

[Travis McGee]

Have you heard any feedback from the Fibbies about their HK MP5/10s? (See #26)

Are they still in use? Have they had problems?

Squantos mentioned he heard about some teething problems, some bad mags and cracked mag well, if I remember correctly.

[harpseal]

I saw an FBI agent using a 10mm H&K about November of last year on a government range. i believe they have not changed but that was the last check point I can give.

[harpseal]

My preffered carry gun is either my EAA witness in .45acp with ten round magazine and the ability to carry cocked and locked or hammer down on the loaded chamber for a DA first shot, or my model 1911-A1 with all the bells and whistles. What can I say I am a traditionalist and I like the .45acp round.