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Jeremy S. recently reviewed the Mech Tech Carbine Conversion Unit for the GLOCK 20 and 21. This high-quality upper unit converts your handgun into a pistol-caliber carbine. While Jeremy’s test covered pretty much everything, he decided to send it to me to do a little ballistic testing, especially since I’d shown an unhealthy obsession with converting my GLOCK 21 into as many different guns as I could (previous installments included converting it to 10mm, and creating potentially the world’s only 9mm GLOCK 21.) So would I like to test converting it to a carbine rifle? Yes, yes I would . . .

To start off, let me just echo Jeremy’s findings — the Mech Tech CCU is a great item. It’s well-made, it performs excellently, and it does what it says it will on the box. The pistol lower snaps in quite securely, and it gives you the longer sight radius, attachment rails, and increased power that one would expect from a rifle version of a pistol.

This particular upper was chambered in 10mm. I used my .45 ACP GLOCK 21 lower with a 10mm GLOCK 20 magazine and it worked flawlessly. While I really liked it, if there is anything that I can say it’s missing, it’s that there’s no safety – which isn’t a fault of the upper, it’s a byproduct of using a gun lower that doesn’t have an inherent manually-engageable safety.

That point (to have or not have a manual safety) has been debated ad nauseum in the handgun world. Many people believe that a holstered handgun has no need for an additional safety. Be that as it may, a long gun is usually not holstered, and some sort of safety is usually found on all long guns. I think Jeremy’s suggestion (in the comments of his review) of using a MIC holster as a safety is eminently practical, and it’s the way I’d go when using the Mech Tech CCU.

I did some general chronograph testing for Jeremy’s article, and in addition, I wanted to see how the gel performance would differ from the 16″ barrel vs. the standard GLOCK 20’s 4.6″ barrel. I had tested CorBon’s 155-grain DPX in my prior video from the 4.6″ barrel, so I thought that would make a suitable candidate for testing from the long barrel. Additionally, I had a leftover Buffalo Bore 180-grain JHP from the chronograph testing, so I put that through a block of ClearBallistics synthetic gel while I was at it.

Now, most pistol caliber carbines in the common service calibers don’t usually see that much of a boost in velocity. According to the research done at Ballistics By The Inch and using CorBon DPX as the load for comparison, the differences are small. When using a .45 ACP rifle you can expect about a 127 feet-per-second increase for a DPX as compared to the normal pistol 5″ barrel (1229 fps vs. 1102 fps). For 9mm it’s basically a similar story; a 115-grain DPX travels at 1475 fps from a 16″ barrel, vs. 1315 fps from a 5″ barrel. Those gains are nice, sure, but they’re not tremendously different; they represent abput a 12% increase in velocity.

With 10mm, the story is a lot better; 10mm gains more from a longer barrel than the other service calibers do. I used my own chronograph readings for the DPX, and I also threw in a high-power Buffalo Bore round to see how it would do from the different barrel lengths. The 10mm gets a much bigger boost from the longer barrel; about 250 to 300 fps more for a gain of around 20 to 24% more velocity. Accordingly, the attendant energy increases are much higher too; with the DPX, the carbine delivered 44.84% more energy at the muzzle than the stock GLOCK 20 did, and with the Buffalo Bore it was a whopping 53.94% increase in energy (from 667 ft/lbs up to 1,027 ft/lbs).

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That’s a lot of added power!

So then the question became – can we harness that power? Or will the ammo be overdriven and disintegrate? I put four rounds of DPX through a block of professional ballistics gel, 2 shots with denim and 2 shots bare (unfortunately, one of the bullets exited out of the side of the block and was lost). I then used the last Buffalo Bore bullet I had, sending it into a block of ClearBallistics synthetic ballistic gel.

From a distance of about 10 feet to the gel block, and with the velocity increases as noted, the answer is yeah, it was too much for the bullets to handle. The DPX bullets expanded and shed many of their petals; one bullet sheared off all six petals, one sheared off four, and one lost two. But the performance was quite good regardless – there was a massive expansion cavity, the initial damage tracks are huge, and the impressive thing was that the copper core of the DPX stayed fully intact so that even after shaving off some or all of the petals, we were still left with a quite large, reasonably heavy bullet that penetrated 20” or more. It wasn’t textbook perfect performance, but it was still very very good. The petals generally didn’t shear off until 8”+ in the gel block – so they stayed attached and contributed to the damage up to at least 8”, and some didn’t detach until 12” or further. That’s not bad at all.

The Buffalo Bore bullet was a more conventional jacketed hollowpoint over lead, and it fragmented all its petals in the initial damage cavity. The bullet started expanding right away and the force of impact just sheared the petals off right then and there. The result, interestingly enough, looked an awful lot like a G2 R.I.P. or a Liberty fragmenting bullet – an initial “starburst” of fragmentation, followed by a long thin trail of damage done by the core of the bullet. In the Buffalo Bore ammo’s case, that core was a smashed-flat bullet of commendable weight and size; it sent a 107-grain chunk of lead penetrating a full 14”+ while expanding to .583”; there’s nothing to complain about that!

However, I didn’t think either performance was really ideal; I think it’d be interesting to test a bullet that’s been engineered to perform properly at these velocities – that could be incredible. Or, consider something like a hardcast bullet (if hunting larger game or defending against larger predators); a hardcast 10mm would probably be an outstanding load at these velocities.

When talking about longer range though, both these bullets may actually be ideal performers. While those Buffalo Bore bullets were traveling 1600+ fps at the muzzle (and thus ripped themselves apart on impact), according to Buffalo Bore they’d slow down to about 1300 fps by the time they reached 75 yards. And that’s right at the sweet spot where the bullet performs best. So if you were using the carbine for targets at 75 to 100 yards away, the additional power would ensure that the bullet still had plenty of power to perform properly by the time it got there. So while these two types of ammo weren’t ideal performers at up-close ranges, they may very well excel at 75-100 yard targets. The carbine’s additional speed would ensure that the bullet was still fully performing at its ideal design velocity when it hit the target, and that’s a great thing.

Overall, I was quite impressed with the Mech Tech Carbine Conversion Unit, and it may represent my favorite iteration of the FrankenGLOCK phenomenon so far.

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    • Two things about the 1911 conversion:
      1) the 1911 has an integrated safety already, so that eliminates that as a concern, and
      2) Mech Tech Systems makes the carbine conversion unit in .460 Rowland for the 1911 platform. They don’t offer it for the Glock, but for the 1911 they do. That’d get you notably more power than even the 10mm version, plus you’d have the ability to shoot .45 ACP and .45 Super as well.

      • Er. Mu. Gerd. I didnt think about the .460 Rowland. In a carbine that would be impressive indeed. Muchos gracias.

    • I have one, using a cheap old Norinco .45 1911 lower. It’s fun to shoot, with almost no felt recoil and very accurate (by my non-professional standards).

      I really like my Mech Tech CCU.

  1. Thank you STB410. Your tests are a refreshing oasis of knowledge in the desert of internet assumers. A Mech Tech CCU for my G17 is definitely on my Christmas list.

    My belief is the reason handgun ammo doesn’t usually get much of a velocity boost when fired through a carbine is because it’s designed for a pistol. It’s made with fast burning powder that tends to run out of gas before the bullet gets down a longer barrel.

    My chronograph testing (pistol vs. Hi-Point carbine) on 9mm 115 grain, has revealed that powder choice can make a significant difference. Two different powders that give similar velocities out of a pistol can yield quite different velocities out of a carbine. Slower burning powders seem to make better use of the longer barrel.

    So the bottom line, as I see it, is if you want optimum performance from a pistol caliber carbine, you need to load ammo that is optimized for a carbine.

    • Yes, or… use a magnum revolver cartridge. .357 Magnum and .44 Magnum both gain massive power increases when fired from longer barrels.

      Consider the .357 Magnum; using their real-world guns data, there’s significant power increases possible. A 125-grain DPX bullet from a 4″-barrel S&W 686 delivered 1438 fps, for KE of 574 ft/lbs. But the same bullet fired from a 16″-barrel Winchester 94 clocked in at 1,935 fps, almost a 500 fps increase! That pushes the KE to 1,039 ft/lbs, an increase of over 81%. That’s some serious power gain.

      With the .44 Magnum it’s just as impressive. They tested a 4″-barrel S&W 629-5 with the 225-grain DPX and saw 1087 fps from it, meaning 590 ft/lbs; from a 20″-barrel Henry Big Boy the same ammo went 1527 fps, a gain of 440 fps and a resulting KE level of 1165 ft/lbs. That’s a gain of 97.5% more kinetic energy (granted, that’s also a lot longer barrel, but they didn’t have any real-world weapon tests of a 16″ barrel, they only show data going from 12″ or 20″. The 12″ barrel still showed a gain of 346 fps (to 1433 fps) and the resulting KE would be 1025 ft/lbs, a still-gigantic 74% increase in KE. So if we averaged the results between the 12″ and the 20″ to take a wild guess at what the 16″ would have been, it looks like it might have been about 1480 fps and 1094 ft/lbs… that’d represent an 85% gain in KE, right about on par with the .357 Magnum.

      If you’ve already got a magnum revolver, then a carbine in a magnum caliber would be a way to really draw a lot more power out of the ammo you’re already using (of course, you’re not going to see a Mech Tech CCU for a revolver anytime soon!)

      • “you’re not going to see a Mech Tech CCU for a revolver anytime soon!”
        Plenty of nice lever guns around that would serve that purpose. 🙂

      • ShootingTheBull410,

        You hit the proverbial nail on the head — launching .357 Magnum and .44 Magnum bullets out of long barrels is mighty impressive. I expect my .44 Magnum rifle with its 22 inch barrel to launch 240 grain bullets at 1,850 fps minimum. That translates to 1,824 ft-lbs of kinetic energy at the muzzle! And out to 150 yards, that bullet is still moving along at something like 1,320 fps with 928 ft-lbs kinetic energy. In other words a .44 Magnum long gun has about the same velocity and energy at 150 yards as a revolver (with a 5 inch barrel) at the muzzle!

        Note that you need to use loads with maximum SAAMI pressures to achieve those major increases … watered down loads don’t cut it.

  2. I’ve been afraid of blowing up my gun with Buffalo Bore LOL. ON a sober note the verdict of a Park ForestIL cop on trial for MURDERING a 95year old WW2 vet in a retirement home is in. Oh wait-it was just for excessive force after shooting the old guy 5 TIMES with a beanbag shotgun round. NOT GUILTY…and another cop kills with impunity. Get excited about THIS TTAG…

    • Submitting it through more official Chanel’s would get a faster response, can’t count on Farago or one of the others stumbling across a specific post.

      • Drew I brought it up last month and several people commented. And they cover every goofy story you could think of…or stumble over. This was a big story locally in Chicagoland. It’s already been shouted out. The cop still got off scot free…

  3. Federal has a nice load that as I recall is a jacketed soft point, and they actually load it to something close to “true” 10 mm power. That might be a nice commercial cartridge to run through a Glock pistol carbine like this.

    • Yes, Federal just introduced a new “full power” 10mm load at SHOT Show 2015. It’s indeed a JSP, in their “Vital Shok” line; 180 grains at 1,275 fps from a handgun.

      It’s really nice to see a major manufacturer offering a full-power 10mm load; for the longest time it was really only Winchester that offered a non-watered-down 10mm load, and that was only with the age-old Silvertip design. For any other full-power load, you had to turn to smaller manufacturers like Buffalo Bore or DoubleTap. So it’s great to see another of the “majors” offering it, and I’m optimistic that with the new Glock 40 being introduced, maybe we’ll see more 10mm loads introduced.

      Like you say, I bet a JSP like this new Federal would be a quite devastating from a carbine like this.

      • I’ve shot it through my 20 at the range. It’s a good “What the$@&! was THAT?” conversation starter when everyone else is shooting 9 and 40 🙂

        Thank you for such excellent and thoughtful reviews STB

  4. With the DPX, that would be a lot of work for a doctor to fix if shot into a bad guy. Maybe to much work. However I am not a fan of pistol caliber carbines personally. That’s just how I feel. Not saying they are bad, just a personal feeling.

  5. One benefit is carbine use on indoor ranges that don’t allow rifle calibers. If you are hard pressed for time and space to practice with your rifle carbine, the pistol caliber carbine might be an option for home defense or whatever if that is all you can reasonably train with.

    Another benefit is if you reload and just prefer to focus on one cartridge – 10mm seems like a nice, versatile option for that.

    Given the choice, I would still opt for my AR but in certain circumstances, these could make a lot of sense.

  6. Will the Mec Tech .45 ACP For Glock 21 Handle 45 Super loads? Also what type of accuracy did it get at 100 yards? And don’t give me some nonsense about it not being designed for that. I don’t care, it’s a rifle, put it on a bench with a big scope at see what it will do. The only useful rifle is an accurate rifle and the more accurate the more user!

    • I only officially rested the Mech-Tech at 25 yards but it was highly accurate. I shot it offhand at 45-50 yards at a small steel target and couldn’t miss. It has a 16″ barrel and a shoulder stock. The barrel is very high quality. You can expect good accuracy. I suppose the only downside is that it’s still a pistol round at a lower velocity than a typical rifle round so it’s in the air longer, which gives the wind and such more time to mess with it and it’s going to drop more due to more time in the air and lower ballistic coefficient. That can make it harder to be as consistently accurate as a rifle caliber in some conditions, but mechanically the Mech-Tech conversions are quite capable.

  7. I’d be very interested to hear how the accuracy is with 10mm auto. The ole wristsnapper handles amazingly in a carbine, but it’s just such an unpopular round that your selection for it is…limited at best.

    • There’s a Facebook page “10mm ammo” and he does the you Tube videos and has a lot of testing with the 10mm ccu and the g20..the glock 20sf I have 2in groups at 25yrds..though I do reload..many other companies 10mm ammo now. .great lakes ammo…lax ammo..Georgia arms..but reloading is the best for 10mm..I load a 200gr xtp at 1300fps or a 180gr at 1400..drop in lone wolf 40 barrel or others. ..simply a versatile pistol..I have a 6in storm lake for deer hunting and like it a lot..

  8. Hmmm. For the guy who wants to KISS, this is very interesting. The point of a long gun is to shoot long.
    For Home Defense that doesnt have to be 1000 yds, just out to the back fence or down the block a bit, if you want to engage the shuffling zombies before they come thru the windows.

    A guy would have two semi-autos, for parts redundancy, one caliber of ammo for simplicity and reloading, and one carbine conversion upper, for as needed, for all the red-dots to be accurate to 100 yds, and attachment points for tac-lites, FLIRS, cell phone jammers, and rape whistles, as required.

    KISS with flexibility. In 460 Rowland for Big Bear country.

  9. ShootingTheBull410:

    I am interested in hearing what your thoughts would be on an ideal performing bullet from a pcc. In my mind it could go a couple different ways: a perfectly expanding JHP that expands quite large without shedding mass and penetrates to 16″ while leaving the barrel with 800+ ft/lbs of muzzle energy…. or a light for caliber bullet that reaches velocities near to or equal to something like a 75 grain hornady tap .223 round out of a AR-15 (~2500 fps). 77 grain otm bullets also fragment somewhat early on with typically a 30+ grain fragment driving to FBI acceptable penetration in ballistics gel. I know fragmenting/jacket separation is a big negative in handgun rounds, but what if the projectile is traveling at rifle velocities? Either way I would love to see some 60 grain liberty 10MM in ballistics gel- rated at 2400 fps out of a handgun- I would imagine close to 2700fps or more out of this carbine.

  10. That DPX, like a lot of commercial 10mm ammo is severely under-loaded. They only have it loaded to .40 S&W velocities. A properly loaded 10mm round with a 155 grain bullet should be pushing 1500 fps. Then again, 155 grain bullets are only designed to be pushed at .40 S&W velocities.

  11. Does the chamber support look good? Just the fact you fired fired buffalo bore tells me it is internet hype that you can’t use certain brands of heavy 10mm..been nice to try some underwood or double tap…though most wouldn’t feed hot 10 continually anyhow and Really not needed book loads of 800x or aa9 would still do better without any problems. Next question is can you use cast lead in it for practice? I shoot cast lead in my glock but constantly check and clean with hopps and wire brush. This would be a fine addition to the glock 20..the best combat semi in the world..

  12. Actually this would be a good illustration of the ineffectiveness (stupidity) of an assault rifle law. You snap on that upper and stock and it becomes illegal in the state of California w/o a bullet button or some other sort fixed magazine arrangement.

  13. converting a glock into a carbine is one of the best innovation of handguns nowadays. If the the glock that would be converted into carbine rifle uses 10mm, I think it should have a different name because there will be a big difference already compared to the original glock.

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