10mm Ammunition – The Perfect 10

by Doug Gilmer
10mm ammunition is just perfect.

10mm Ammunition
10mm Ammunition
AmmoLand Gun News
AmmoLand Gun News

USA -(AmmoLand.com)- The 80’s television show Miami Vice featured colorful suits, fast cars, beautiful women, expensive boats, and guns.

Detectives Crocket and Tubbs took down the bad guys in style. While Tubbs was more conservative in his approach to firearms, a couple of snub-nosed 38’s, Crocket introduced the world to the 10mm ammunition in the form of a Bren Ten.

Manufactured by Norma in the early 1980’s, the 10mm was the idea of Col. Jeff Cooper who dreamed of a 40 caliber cartridge propelling 200 grain bullets at 1000 feet per second and generating 444 foot-pounds of energy. He envisioned the perfect handgun round for law enforcement.

Years later, Don Johnson, playing Sonny Crockett, would help propel Col. Cooper’s idea into the mainstream.

Sonny Crockett and the Bren Ten
Sonny Crockett and the Bren Ten

After the infamous FBI Miami shootout where the agent’s 9mm ammo underperformed, the FBI adopted the 10mm in a Smith & Wesson Model 1076. State and local agencies followed.

The original load, a 170 grain bullet at over 1300 fps, delivered over 600 foot-pounds of energy.

It wasn’t long, however, before the large handgun and its accompanying recoil proved too much for some agents and officers to handle. 10mm ammunition was downloaded to a 180 grain bullet at about 950 fps. Smith & Wesson figured out the tamer ballistics could be duplicated in a more compact cartridge leading to the introduction of the 40 S&W.

Today the 10mm is to the 40 S&W what the 357 Magnum is to the 38 Special.

With the popularity of the 40 S&W as a law enforcement duty round, the 10mm shrunk almost to obscurity except for a small but dedicated group of followers aided by Glock’s decision to keep their Glock 10mm guns in production.

The Glock 40 is at home in the woods where shots tend to be under 50 yards in most cases
The Glock 40 is at home in the woods where shots tend to be under 50 yards in most cases

Lately, the 10mm ammunition is making a resurgence. Glock, Sig Sauer, Kimber, Rock Island Armory, CZ, Dan Wesson, and EAA are just some of the companies building 10mm pistols. There are still some Smith & Wesson Model 610 revolvers and Ruger Blackhawks with 10mm cylinders around as well. Today 10mm ammunition is easy to find with boxes of 50 rounds (FMJ target loads) selling for $23 and sometimes less.

10mm ammunition (left) compared to its sibling, the 40 S&w
10mm ammunition (left) compared to its sibling, the 40 S&W

Is 10mm ammunition closer to the 357 or 41 magnum in power?

Paper ballistics with standard factory loads show the 10mm and 357 closely matched. However, Underwood, Buffalo Bore, and DoubleTap load the 10mm with 200 grain bullets at 1250 fps and 220 grain bullets at 1200 fps out of standard length barrels; serious power for a semi-automatic handgun. While the 357 is no slouch, the 10mm, with its bigger, heavier bullets, sits solidly in the 41 magnum’s wheelhouse. The Taylor Knock-Out Value formula* bears this out.

This kind of power makes 10mm ammunition popular as a hunting cartridge. Whitetails, hogs, black bears and even bigger game are no match for the 10mm and well constructed 180 or 200 grain bullets. In my experience, the 180’s are fine for deer but the 200 grain bullets take the 10mm to a new level of performance. I have hunted a great deal with the 10mm and am impressed with its accuracy, flat trajectory and down range performance. This past fall I took an adult doe at 35 yards with my Glock 40 10mm and a 200 grain Nosler bullet loaded by Underwood Ammunition. A 30-06 wouldn’t have dropped her faster.

The Glock 40 in 10mm makes a formidable deer hunting handgun. 10mm ammunition
The Glock 40 in 10mm makes a formidable deer hunting handgun

10mm Ammunition Is A Do Everything Cartridge.

With proper loads its recoil is easily managed. It has a solid track record as a self defense round. Quality defensive ammo in the 135 to 180 grain range is controllable while shooting but offers the ballistics and stopping power to make Col. Cooper proud. Some western law enforcement agencies still issue or authorize the 10mm for duty use. The 10mm easily handles medium to large game and it’s seeing more use in Alaska with those who frequent the outdoors and are in need of lightweight, fast handling, easy to shoot, deep penetrating cartridge for defense against big bears. I carried my Glock 20 loaded with 220 grain hard cast bullets with me on several trips to the Last Frontier and never felt I was lacking in power for anything I might encounter.

Left to right: 44 Magnum, 44 Special, 41 Magnum, 10mm Ammunition, 40 S&W, 357 Magnum, 38 Special
Left to right: 44 Magnum, 44 Special, 41 Magnum, 10mm Ammunition, 40 S&W, 357 Magnum, 38 Special

10mm ammunition is an all around efficient and versatile cartridge. It may not be the best all-around self defense cartridge nor is it the perfect cartridge (if there is such a thing) for tackling big game. Still, it does both equally well within its limitations. If one could only own one handgun to cover duty from back alleys to the backwoods, the 10mm would be hard to beat.

*The Taylor Knock-Out Value is calculated by multiplying bullet diameter (i.e. .40) x bullet weight in grains x bullet velocity in feet per second, then divided by 7000. For example, (.40 x 220 x 1200) ÷ 7000 = 15.08.

The Dan Wesson Bruin is an example of a custom gun that features 10mm ammunition in a familiar 1911 style frame.
The Dan Wesson Bruin is an example of a custom gun that features 10mm ammunition in a familiar 1911 style frame.

About Doug Gilmer:

Doug Gilmer is a law enforcement and military veteran with over 25 years of experience and assignments operating throughout the United States and around the world in a variety of investigative, protective, tactical and direct action roles. He is an avid outdoorsman who enjoys fly-fishing, hunting with a handgun, backcountry adventures, and volunteering with various outdoor themed wounded warrior events. He has been a frequent contributor to outdoor media for for several years with numerous articles and photos published in a number of media channels. He is a member of the Professional Outdoor Media Association as well as a former board member and executive officer.

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I purchased a glock 40 10 mm a few months ago love it, my wife shoots it with no problems. Carried during last deer season and plan on taking hogs with it. I love my glock, good gun 4 the money. Own a g 19 as well.


Just ordered mine yesterday with a Trijicon Rm06 on top. Can’t wait to get it. Now the research for Whitetail loads.



Tony M

So what? The 10mm is an incredible cartridge. Extremely accurate in every firearm I have experienced since the early 90’s. Loaded with135gr hollow points at 1600-1700fps it an excellent choice for self defense. And with the heavier hard cast loads in a 15 + 1 Glock you have more firepower in a handgun than anything else. Bad guys to bears and you’re good to go.
I have asked myself many times…. 6 rounds in 44mag or 16 in 10mm in bear country. Give me the 10mm

Wild Bill

I think that the 10mm is making a comeback of sorts. The .41 has its followers. My grandpa used to shoot 16 ga. It has a lot less recoil. I shoot his shotgun, now. During the ammunition shortage, I was able to get plenty of cheap 16 ga and 6.5 x 55, so the odd ball calibers do have their advantages. I think that the oddball calibers provide a kind of gourmet flavor to the shooting sports, as one gets older in the sport of shooting. Yesterday, I picked up a little Sako in .222 Remington just for fun. I… Read more »

Grey Beard

You should have an absolute Ball with that 222 Remington. I’m now officially jealous.


Very informative article. Like you eluded to, I’ve dropped deer with my Glock 40 three years running and only had to trail the last one 20 yards. I’m a .308 Winchester rifleman and have had to trail deer for years after the shot. Shot placement is always king, but I’ve been amazed at the 10mm rounds efficiency and knockdown power (if there is such a thing). I own the Dan Wesson Bruin also but my eyes don’t see iron sights like they used to. It is supremely accurate and out classes my Glock hands down, but the Glock MOS is… Read more »


Dear author and others who read this comment,
I would like to know more game hunting stories about the 10mm? What different kinds of game you’ve seen taken with it and the backstory to that (ammo style/design, distance of the shot, how many shots were needed on the game from the 10mm, etc). Could a 10mm take massive game like elks and moose also? Ive got zero doubts it can take deer, hogs, etc.

Also, what are some of the best States for handgun hunting?



A 10mm with Underwood 220 gr HC will kill a moose or elk no problem. I have seen a video of the remnants of a bull moose in Alaska that got in a guys fenced in yard trying to kill his dog during the rut. 4 shots broad side.

William Smith

What happened to the Glock 20 and the 29, both 10 mm? I understand that the Glock 40 10 mm has a 6′ barrel


So as a competition marksman, avid hunter, and all around complete gun nut, I have to say that the 10mm is the round for me. It’s great as a handgun round (I have a Dan Wesson Bruin and the Remington r1 longslide hunter) and it’s superb as a pistol caliber carbine. The 6 inch barrel for hand guns ( just because I like more weight on the forward end) and 16 inch carbines is where I’m most at home. I’ve chronographed some of my hotter loads at about 2300 FPS from a handgun ( firing 85 grain ballistic tips) and… Read more »

Steve lee

Greetings: just curious…what 10mm factory ammo would you try in a hi-point 10mm carbine?

Seabee CPO

Tough crowd, I won’t tell you I did 28 years in the military, or that a bow with as little as 125 ft lbs has killed many a deer. I want to talk about my 2 – 10mms ! Rock Island shoots straight mild recoil, read heavy, and my Glock I take out of the safe every so often and amaze myself at how well it shoots for a blue flame barking hand cannon ! LOVE IT !


Tough crowd, I won’t tell you I did 28 years in the military, or that a bow with as little as 125 ft lbs has killed many a deer. I want to talk about my 2 – 10mms ! Rock Island shoots straight mild recoil, read heavy, and my Glock I take out of the safe every so often and amaze myself at how well it shoots for a blue flame barking hand cannon ! LOVE IT !

A Brown

More accurate to refer to the .40 S&W as the off-spring rather than sibling. Thanks for the write-up.

Eberhardt Huhn

The .40 more like the afterbirth, or the Danny DeVito from “Twins”…


In a world that has lost it’s collective mind i carry a glock G40 10mm with plenty of ammo (never know when the zombie apoclypse will start) i am alive today because i had a 1911A1 when my rifle ran dry, love the 45ACP as a man stopper. I hunt with a custom Mauser in 6.5×55 swede best dear rifle ever in my humble opinion. Shoots sub minute of angle at 100 meters all day every day. (if i do my part) 6.5 swede for the 4 legged critters, 10mm for the 2 legged critters and dangers game at close… Read more »


^He’s a liar, and his humble opinion is anything but.

Eberhardt Huhn

Phanjo11B says: “I have 27 years as a Infantrymen, 23 years as a police officer…”

Was that at the same time that you spentt 20 years as a wizard, a toothfairy, and a dentist, as well as 25 years as an Indian, which happened concurently to the 25 years you were a cowboy?


It’s called being a reservist and having a LE career that overlaps with a military career. Just because you don’t agree with someone and can’t think outside a narrow box enough to figure out how a person could be telling the truth doesn’t make them a liar. As a matter of fact, if he did 4 years active duty then dropped into the reserves and joined a police force right after, he could’ve served most of those 23 years as a cop while being a grunt and retired at almost the same time.


You are an ass-clown


Tony m has a vert good point. Whoever I am out i camping or hiking in bear country I also carry my 10mm loaded up with double taps excellent 200at 1200 fps rated jhp. 10rds on board ,plus 18more on hand for quick reload. Mine is a s&w 1006 a little heavy but very reassuring! I find it easy to shoot and accurate. Out here in the west shots tend to longer at times and it’s added power and range are welcome.

Tony M

Westerner, the 1006 was the most accurate handgun I have ever owned and I’ve owned quite a few. I carry a Glock 20sf now with 2 spare mags. Depending on the time of year it’s either 135gr Underwood or 180gr. Either way with 46 rounds of incredible energy I think I’m prepared for anything barring a total apocalyptic event. Ha.


Considering the all encompassing tissue damage due to damage hydrostatic shock, the near recoil of a 22 rim fire (excellent target re-acquisition), a standard 20-round magazine, and the ability to consistently hit the 10-ring out at 50 plus yards, and I’d say that in the next 4-6 years, the 5.7x28mm will be gaining ground (not dominating) in all aspects of law enforcement.


I carry the 10mm out west in Montana for all the reasons sited. 15 rounds in my Glock tend to make me feel secure. I’M 65 and not so old that I can’t handle the recoil. I use Underwood ammo with a 6 inch barrel from the folks out at Lone Wolf in Montana. The pistol is large…… so are grizzlies. When 4 wheeling out in Moab, AZ it provides peace of mind on days we go way out into the desert. Would something smaller work? Maybe. Butbetter to have it and not need it than to need it and… Read more »


Moab is in Utah


I find it odd that the TKOF is referenced without irony, with a link to Chuck Hawks indicating no serious journalist would do so.


Thumbz up 10mil. Carrying one now due to increased capacity, ballistics and stopping power. Still have the .45 as standby but the 10 is now my primary.

Mike L.

I am a proud owner of a WITNESS/HUNTER , 10 mm, 6 in barrel, 15 RD magizine. Quality and finish is beautiful and easily handles all ammo with very easy handling recoil. I had a Glock 10mm back in 90 and had lots of fun shooting bowling pins. Hunting was not allowed in PA with semi auto firearms except squirrels and it was a little too much for them… I will be carrying this handgun in a custom shoulder holster for ELK season accompanying my Elk rifle. If a under 100 yd shot presents itselfI will take the shot.. But… Read more »


6.5×55 ??? this oddball cartridge has been around longer than most of us,and today is probally one of the most accurate rifle cartridges,my mod.96 swed.mauser is definatly my most accurate

Wild Bill

You are correct John, the 6.5×55 Swede has been around since 1894. The more experienced shooters know about its’ legendary accuracy, but the more modern crowd thinks that the only 6.5 cartridge is the Creedmore Grendel, or the Lapua. The fact that you still shoot a 6.5 Swede from a Swedish Mauser evidences your knowledge, intelligence, and sense of history. I like that cartridge as well as anything that I have ever shot! Feeds well, mild recoil, plenty of knock down power, inexpensive, and there is the terrific accuracy that you have already mentioned. Maybe we should keep it our… Read more »

Grey Beard

Uh oh, I’m afraid your “little secret” is shared by another. In addition to a Swede Mauser, I also have a Winchester 70 Featherweight in that caliber. I love them both.
As to the 10mm, I have a 1076 which I Love to shoot, and now feel I should get another top end for my Witness.

Wild Bill

Whoa, there partner! A Winchester model 70 Featherweight in 6.5 Swedish! Now I am officially jealous!


Thanks amen,,,


Sorry, but the ultra-heavy recoil is not enjoyable to old, retired fossils like me. I’ll stay with the modern 9mm hollowpoints, thank you.

Mike L

Then your shooting an inferior pistol,,,, Witness/Hunter 6 in barrel, semi auto. Many a times women who have fired my weapon have been surprised by both accuracy and lower than expected recoil that second shots were easily controlled.
I owned a Glock 10mm for awhile and really liked it UNTIL I Saw the Witness in 10mm, 6 in barrel. Game on ever since !

Daniel E. Watters

FWIW: The FBI’s Firearms Training Unit selected the mid-velocity 10mm load before the Bureau ever selected a pistol for issue. The issues with the FBI’s S&W 1076 were not related to full-power ammunition.


Doug, which round do you think is best for self-defense?


Dear Superman, Riddle me this? You are hiking in Griz and Black Bear country and are unfortunate enough to get attacked by one of these beasts. Which sidearm would you rather be carrying? A .357 with 6 or 7 rounds or a Glock 40 with 16 rounds of hard cast Bufffalo Bore that has the same foot pounds of energy at 100 yards that the 45 APC has at the muzzle? There is a reason why the 10 is being issued to Arctic Rangers in Scandanavia to deal with Polar Bears and the Dreded Yeti Snowman. I enjoyed this article… Read more »

Don Bailey

@Doc, You didn’t ask me, but I’ll give you my answer to to your question. I would choose the Glock 40 with 16 rounds. I’ve done the research on the performance on most all these types of ammunition. If you google the ballistic gel performance of any of the various types of ammunition available on the market today, you’d be very impressed, especially that of the 10mm. The Glock 40 is also about as reliable as any handgun made.


Hi Doc
Arctic Rangers in Scandinavia????? What are you talking about here. The only country in Scandinavia that actually might run into polar bears are Norway and it would be on Svalbard or one of the other Arctic islands where the military are prohibited, because they are not Norwegian territory. Polar bears have never been seen on any mainland in Scandinavia, or Norway for that matter.

Sgt. Stryker

Easy there Thor. I’m not sure, but his reference to arctic rangers, polar bears and yeti snowmen might just possibly have been a mildly amusing attempt at euphemism.
Cheers and regards to the Allfather, Óðinn.

Clark Kent

Doc: You completely missed the point of my missive. By the way, the author mentioned hunting DEER, not bear. Take a reading comprehension 101 class.


Superman, You’re kidding right? Did you just tell somebody to take a reading comprehension class after, very obviously, not fully reading or comprehending what the author wrote yourself? Let me spell it out for you… You said, “By the way, the author mentioned hunting DEER, not bear.” The author mentions bear twice actually… Once here, “Whitetails, hogs, black bears and even bigger game are no match for the 10mm and well constructed 180 or 200 grain bullets.” And then once again here, “The 10mm easily handles medium to large game and it’s seeing more use in Alaska with those who… Read more »

Ed Fortune

Its called the Sirius Patrol (sled dog patrol in national park of north east Greenland) they use the Glock 20 and the 1917 30-06 rifle.

Clark Kent

The 10mm will suffer from the same fate as the 41 Magnum round and the 16 gauge shotgun shell. It will hang on due to those devoted to shooting oddball rounds but will never break into the big leagues. By the way, the 223 Remington or 357 Magnum cartridges will drop an adult doe at 35 yards. So what?


Some states, MO, require .40 cal for deer!


So will a 16 ga with slugs…


Always gets compared to the .41 mag somehow. Not even close when shooting good ammo out of each. Some of my best results from my chronograph data. .44 mag 340 HC UW 9.5″. KE- 1,631 ft-lbs, PF- 500, KOV- 30.7 .41 mag 265 gr GZ HC 8.5″. KE- 1,306 ft-lbs, PF- 398, KOV- 23.1 10mm 220 gr HC Underwood. KE- 750 ft-lbs, PF- 273, KOV- 15.6 10mm 200 gr HC Underwood. KE- 753 ft-lbs, PF- 264, KOV- 14.9 10mm 180 gr Fenix Ammo. 729 ft-lbs, PF – 244, KOV – 13.9 10mm 180 gr Underwood. KE- 688 ft-lbs, PF- 236,… Read more »


Hi, I have used Bludot, AA#9, AA#7, BE-86, Power Pistol yet I have not been abe to make a load that is accurate pass 10 yards using my Kimber 10mm Eclipse II custom. even double Tap & Underwood behaves the same. 180 gr and 20 gr nosler and Sierra bullets. any idea why? any light you can she on this problem please? Regards, Masood


You need a stiffer recoil spring. that’s the problem. you will also get more consistent and higher velocities with a stiffer spring for those powerful loads. Go 21 or 22 pounds on the spring, use a wolf spring if you can get one. that will solve your problems.


The recoil spring comment of going to a wolf 21 or 22 pound spring , is intended for Masood.


Thank you Jeff.

I ended up sending the firearm to Kimber and after reviews they replaced it and I got a TLR/RL and it is as accurate as it gets using Underwood Ammo and my own loads using Power Pistol, Blue Dot with CCI300 primer and Seirra 180 grains JHP bullets. Tried all things equal and uniform. Recoil spring seem more stiff than what the old one had which was 18.5 lb. thanks for replaying and best Regards, Masood


I use a Glock 20 with 180 gr trophy bonded Federal Premium. A 300 lb hog went down with one shot at 35 yrds and the bullet didn’t pass thru. 1250 fps from the six in. barrel.

Doug Baker

I think this really is not the place for dissent.It is a place of just what’s in a person’s Heart.


I don’t own one YET, but I will soon. Most likely the G40 Gen 4, with the addition of a custom 6″ barrel. My only question is: doesn’t Glock recommend against shooting lead bullets in their pistols?