Pistol-Caliber Carbines

Richard Mann at Shooting Illustrated has evaluated a few different pistol cartridge chambered carbines and compared then with the M4-style carbines in 5.56mm and pistols chambered in the same rounds.

Bushmaster Carbon-15 carbine

Richard says …

With the versatility of an M4-style carbine in 5.56 NATO a given, it still may not be as cool as some pistol-caliber carbines. For fighting bad guys at rock-throwing ranges, it may be no better. A gun’s cool factor will not save your life, but nevertheless, a cool, pistol-caliber carbine loaded with the right ammo should work just fine. They are indeed more accurate and easier to shoot than any handgun.

Read it here.

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • KC

    Interesting article, I’m actually in the process of building a 9mm AR

  • “With the versatility of an M4-style carbine in 5.56 NATO a given, it still may not be as cool as some pistol-caliber carbines. For fighting bad guys at rock-throwing ranges, it may be no better. A gun’s cool factor will not save your life, but nevertheless, a cool, pistol-caliber carbine loaded with the right ammo should work just fine.”

    Except that we know inside of 20 yards even the shortest 5.56 SBR still has reliable fragmentation (measure an average room). And that pistol rounds have an 85% survival rate. And there’s little to no ballistic benefit running a round designed for a 4″-5″ barrel through a longer pipe. And in practice, 5.56/.223 actually penetrates fewer walls and is safer when faced with over-penetration.

    At least he states most of that. The concept of intentionally putting a less-effective and more dangerous round in a carbine (simultaneously losing a free hand and/or ease of maneuvering) continues to baffle me. A pistol caliber carbine is like the worst of all worlds.

  • Mechman

    Except the Box O’ Truth showed that the 5.56 penetrates more walls than pistol rounds.
    You can use frangible rounds to make it penetrate less than the pistol rounds, but you can also get frangible rounds for the pistol that will penetrate less than that. Rifle rounds just have more power behind them, and they will, for a given round type, penetrate more.
    As far as a longer barrel not making a difference, the numbers show that it does make a pretty big difference in the performance of the rounds in both expansion and penetration.
    Are pistol caliber carbines better? Sometimes they are, sometimes they aren’t. It all depends on what you need.

  • Kyle

    Of course, a pistol caliber carbine can have its uses, and it’s certainly better than throwing rocks, but I personally would have to grab for a 5.56 platform. I have a philosophy on these sort of things that I personally follow and am not imposing on anyone else and that is: “Keep the pistol ammunition in the pistols, and the rifle ammunition in the rifle!”. That been said, I’d also like to say that, in a full auto platform, I would treat a pistol-carbine as I would any subgun, no matter barrel length

  • Elkroppo

    I love the idea of a pistol caliber carbine. The folks at ballistics by the inch found that velocities rose until about a twelve inch barrel for a 40 sw, so there is still plenty of oomph to be gained. Plus you don’t have the horrendous muzzle blast and flash of a 556 sbr.

  • Pete Sheppard

    For extensive use in enclosed spaces, the reduced flash/report of a pistol-caliber carbine could be a factor. For an HD weapon, where the user might not have time to put on hearing protection, it could be the difference between a bad ringing and total deafness.

  • Marc

    @Eric R. Shelton
    You missed one factor: Noise. Not to be underestimated in home defense, when you want your hearing to detect a possible intruder and maybe still want it after firing a shot.

  • 4Cammer

    Love my Ruger PC9…..

  • Sean Albrite

    This guy does a whole write up on Pistol shooting AR’s and Carbines and doesn’t mention anything about the 10mm…that make me sad.

  • “A pistol caliber carbine is like the worst of all worlds”

    I think the boys cleaning out trenches with Thompsons in WWII would disagree. Also they’re just plain fun.

    My biggest reason to choose a pistol caliber carbine would be as my trunk gun. A carbine in your trunk that takes the same magazines and ammo as your handgun would be a pretty sweet setup. No confusion and everything works together.

  • ap

    He makes great points and will open a lot of eyes. That said, .223 is extremely loud inside. If I can’t effectively communicate with my family because our eardrums are bleeding, we’re at a severe disadvantage. Suppressed, now that’s a different story albeit still quite hearing safe (in my experience). And, how long do you want that carbine to be while you’re cutting pie in hallways, etc.? The much overlooked Glasser Safety Slug, on a suppressed .45, handgun make a lot of sense to me. YMMV.

  • Gerald

    Overpenetration is far less of a realistic concern than one might think. For one, given a person sized target, if I point a gun in a random direction and fire, my probability of hitting the target is already small, and drops off as a factor of 1/(R^2), with R being the distance to the target. So a target twice as far away as the one that I am shooting at is 1/4th as likely to get hit. A target 4x further away is 1/16th as likely to get hit, etc.

  • Mechman

    As far as noise, it’s better to have a long barrel for the cartridge and have all the powder burn before it leaves than to have a short barrel and have a foot long fireball.

  • subase

    These carbines should really feature barrel integrated suppressors to justify the extra length. (which is just a legal hoop people want to avoid)

  • ap

    Mechman, shoot .223 from a 16″ carbine and .45 through a 4″ bbl. and get back to me.

  • Laftrick

    You get a big jump in velocity with almost all pistol rounds in a 10 to 14 inch tube. If you don’t believe me get a contender and a chrony. .357 mags gain nearly 400 fps. .40 s&w gain about the same. A 10mm 180gr from a 10 inch tube with the right powder can reach 1800fps. That’s a lot of snap.

    Lots of PDs are having trouble with officers hearing using SBR ARs. A integral can on a SMG makes a lot of sense.

  • subase

    Reliable expansion very high velocities is questionable, so you need tests done. The only bullets I’d trust to expand at all velocities would be those copper ones, corbon DPX and such.

  • Some Guy

    Saying pistol carbines are useless are like saying sub-machine guns are useless.

    I’ll have you know that the Mp5 and Thompson sub-machine gun are, indeed, sub-machine guns.

    The barrel length and weapon (I.E. a rifle platform, not a pistol), usually increases accuracy.

    For a home defense weapon, the number rounds fired + accuracy + reliable expansion in tissue + bullets optimized for short range performance = a win.

    The average MOA of a 1000 dollar Ar-15 is around 2.25, but the average MOA for a 500 dollar sub-machine gun is about 1 MOA.

    The stopping power of the 5.56mm is also debatable, which is why .45 acp or even higher might be preferred.

  • Andy

    Some Guy, there’s a reason SWAT units are ditching their MP5’s in droves. There’s no reason for them to use a pistol cartridge when the can use a rifle cartridge in a firearm of the same size. If you need ultra-quiet suppressed operation, the sub-gun is still the king but that’s a very limited use case.

    Travis Fisher, the popularity of subguns in WWII isn’t evidence that they’re superior rifle-caliber carbines because the latter didn’t exist at the time.

  • Some Guy

    Yeah, but the 5.56m round is crap. Not to mention that, the MP5 generally has 1 MOA or better, compared to the 5.56mm round which is usually 2.25+.

    Plus, Mp5’s are cheaper and generally more reliable than most cheap, modern 5.56mm weapons (I.E. the AR-15). An HK416 or an equivalent, or even something a little crappier, is a generally usable weapon, though.

    Another thing to consider is that, SWAT personnel generally do not own fully automatic weapons. Part of the point of a sub-machine is it’s burst and full auto capability which most SWAT officers don’t have.

    Personally, I don’t really like the .223 remington or the 5.56mm, and if I was a SWAT person, I’d prefer more or less a more powerful 6.8mm remington, 6.5mm grendel, or even bump it up to a 7.62mm x 51mm NATO round. Any issues with weight and recoil are meaningless when I only have a few minute to a few hour combat situation and, hopefully, a patrol car to carry all my stuff in.

    All of that being said, the MP5 really isn’t the ideal sub-machine imo. What we really need to do, is make some form of sub-machine gun carbine, based off of some rifle, firing 10mm auto rounds, that have around the same power as most intermediate rounds (fired from an 8 inch+ barrel), and have been known to be accurate even out to distances of 350 yards when fired from a pistol. They have more power at 100 yards than a .45 ACP does at the muzzle. Main issue? Weight and recoil. Both of which would be resolved in a rifle carbine like system. It’s inherently accurate, and usable out to 300 yards. Actually, it was designed by the FBI to be used in the Thompson Sub-machine gun, and it’s very strange how we’ve never really reintroduced the round.