MechTech Systems makes a upper unit that attaches to a Glock (or 1911) receiver which turns the pistol into a carbine.  First of all, if any of you have any experience w/ these in general I would be curious to hear about it, but mainly, I post here to see if any of you have heard of anyone SBR'ing a Glock w/ one of these units.  

Or perhaps someone knowledgeable could chime in about the technical feasibility of this project.  

The system is a simple blow back design where the pressure pushes the hull out like a piston against he breech face "once pressures have dropped to safe levels."  I vaguely grasp the concept, but I wonder how abbreviating the barrel could affect the function of the weapon.  

It takes a certain amount of energy to motivate the bolt group to cycle the gun, so by shortening the barrel would you be reducing the forces upon the bolt group or changing the timing in some detrimental way?

Or maybe it doesn't matter b/c it is blow-back????

By the way, there reason I am thinking about this is b/c OAL of the unit w/ a given barrel length and stock collapsed is a little less than a G18 type scheme w/ collapsed stock.

The MT carbine uppers are a fantastic idea that has been timidly executed and poorly marketed.  The thing is so damned ugly I had to take it apart and stare at the bits for weeks before I hatched a plan.  There is allot more potential here.

I cut the forend square, shortened and 3-lugged the barrel, cut and fitted an AR15 front sight, milled the scope base lower, fitted an Ar15 carry handle, shortened and re-shaped the stock.

I also added a sear trip to the bolt to run it on a G18 frame but then milled it off to replace it with a sear trip to run on any Glock frame.  Haven't gotten back to that yet.

From the beginning this thing should've been built to fit AR15 accessories, it is VERY accurate, COMPLETELY reliable (is yet to jam) and very easy to use.  From the  POV of high-cap mags, the Glock is a good choice.

I cannot advise on legal issues but feel free to ask technical questions.

That is Fuggin awesomme!

So you shortened the bbl w/o any other mods to the carrier or action spring and it still runs good.

I didn't know there were any pre '86 G18s.  How much are they roughly?

Did you ever get the unit to run w/ a G18 lower full auto?    

What is the bbl length from breech face to crown?  

Can you fit a rear iron sight on the rail behind the EO-Tech?  

You should get the wire collapsible stock for that thing, or perhaps the M4 stock.  

BTW, is the Charging handle on the Gun Reciprocating?  

I'm a dealer/manufacturer who likes to play with guns and read books instead of watching TV, all of my guns are what you would call dealer-samples.  I also have a full machineshop at my house.

The cocking handle reciprocates.

Barrel length I estimate at 10".  9x19 functions on blowback, barrel length does not affect function.

Yes, there are many other stock options.  A folding ACE was also something I considered, but a Grease GUn slider would be OK too.

The rail on the receiver needs to be replaced with a full-length welded picatinny rail.  This is the first effort, if the factory got their shit together it could've had the full length rail and 4-rail handguard from the beginning - that would be my next effort.  If I used a cantilever Aimpoint I could fit a BUIS as well.

A friend of mine has one of these in .38Super.  From the long barrel the ME is VERY impressive, way better than any pistol.

ETA.  I just looked at the website.  Sometimes you can look at a shooting product and just tell the 'designer' spends more time spewing words than lead.

First of all, the length-of-pull is all worng.  Average rifles are built with about 13.5" LOP, tall people prefer about an inch more.  All the stocks pictured are too long by about 4".  The M4 stock FULLY COLLAPSED is about as long as it needs to be.

Secondly, the comb is all wrong.  The sliding stock mount needs to be inverted so the sliders (comb) are an extension of the top of the tube so the shooter can get his head forward on the gun without butting his nose up on the tube.  When the stock collapses the two rods should pass either side of the scope mount, not the pistol frame.

I'd like to spend a weekend with those boys, a lathe, mill and bottle or two of rum.

I have had the same observation about the tele-stock needing to be inverted.  Can a guy just unbolt it and flip it over and bolt it back on? Or would it take some machine work?    

Is that what their tele-stock is, a Grease Gun stock.

The Ace side folder you mentioned, it wouldn't interfere w/ either the charging handle or the ejection port?  I really want to take one of these and make a PDW type out of it and it has to have a fully telescoping stock or a side folder to fit.  

Nice to know Bbl length doesn't affect function.

Quoted: ETA.  I just looked at the website.  Sometimes you can look at a shooting product and just tell the 'designer' spends more time spewing words than lead.

I have a bare Para Ord frame that I keep meaning to match up with one of those uppers.  It should make a decent suppressed platform.

Monkey Man,
Do you know what it would take to invert that wire telestock like you said?  Could it simply be unscrewed, flip over and screwed back on?  Or would it take extensive machining?  

What would it take to mount rails to the hand guard so you could have a 4 rail effect?  

How much does that unit of yours roughly weigh w/o magazine?  

Does the unit have last round hold open feature?

MonkeyMan,

Could you somehow attach a ARMS SIR #50C or similar style hand guard to the factory top rail.  I realize that one might have to add a little extra material somewhere or butcher their factory hand guard.  

Or perhaps a guy could just clamp on an extended rail on the factory rail and then clamp a small 4 rail hand guard to the front end of the extended rail and then find some way to sort of secure it at another point.  

This would be a pretty simple and sweet way to get the unit nice and modular.  

You don't happen to know what the barrel OD is w/ the unit?

It would be easy to mount a 4-rail handguard like a YHM.

The barrel is slightly offset downwards in the receiver tube.  To mount the handguard I'd mill/turn a threaded bush with enough offset to bring the barrel back to true center.  The bush would be turned from steel and tig-welded to the receiver tube.  Then I'd mill a bit of picatinny barstock and weld it to the top of the tube to match the height of the handguard top rail.

There is no BHO feature.

Monkey May (or anyone else),
when the unit is installed on a frame, is the breech face farther forward?  Perhaps when the unit is in battery the cartridge is actually farther forward relative to the frame than it is w/o the mech TEch upper???  I wonder b/c it just seems like the OAL they list w/ stock collapsed is too long.

Can you tell me what the length of your unit is from the muzzle to the back of the receiver, not counting the stock?  Can you please also tell me what is the length of the barrel in your unit from muzzle to breech-face.

Given the innards of the system, what is the shortest possible barrel length you could do w/ one of these uppers?

Thanks

RWN, ANSWERS IN CAPS

Quoted: Monkey May (or anyone else), when the unit is installed on a frame, is the breech face farther forward?  Perhaps when the unit is in battery the cartridge is actually farther forward relative to the frame than it is w/o the mech TEch upper???  I wonder b/c it just seems like the OAL they list w/ stock collapsed is too long.  NO.  IT WORKS ON A SIMPLE BLOWBACK PRINCIPLE LIKE AN OPEN-BOLT SMG.  THE EXTRA LENGTH IS REQUIRED FOR THE HEAVY BOLT AND ITS TRAVEL TO ABSORB RECOIL. Can you tell me what the length of your unit is from the muzzle to the back of the receiver, not counting the stock?  18" Can you please also tell me what is the length of the barrel in your unit from muzzle to breech-face. 11" Given the innards of the system, what is the shortest possible barrel length you could do w/ one of these uppers?  IN ORDER TO MAKE MINE I CUT THE FRONT OF THE RECEIVER OFF TO SQUARE IT.  I PROBABLY REMOVED 1.5".  IT MIGHT BE POSSIBLE TO REMOVE A FURTHER 2" OF RECEIVER TUBE BUT WOULD REQUIRED MORE MACHINING TO RETAIN THE SHORTER TRUNNION IN THE TUBE. Thanks

Thank you so much monkey man.  That is very kind of you.  

The Mech Tech is interesting.

I would rather take a G17L, SBR it, screw on a suppressor and then put the Glock stock on it.

Quoted: The Mech Tech is interesting. I would rather take a G17L, SBR it, screw on a suppressor and then put the Glock stock on it. thumb3.webshots.net/s/thumb3/5/75/18/108057518RZasqV_th.jpg

I did that too; a couple problems:

Pistol sights are designed to be aligned at arms-length.  The Glock stock brings the eye closer to the sight and makes it more difficult to aim.  A regular Glock will shoot about 5" at 25yds, with the stock it will shoot slightly better and the MechTec will shoot better than 2".  Hitting bottles past 50yds with the MT is relatively easy, impossible with the Glock pistol.  The Glock stock is also very wobbly.

Secondly, I built this primarliy as an SMG.  I owned a G18 and still own a FSSG select-fire switch and both are absolutely useless.  My purpose was simply to see if the platform could make a good, reliable, accurate closed-bolt subgun - it does.  Anyone who has a G18 or autoswitch registered Glock receiver could make a much better gun with one of these.  I own many subguns and I'd say the only better-shooting one is the MP5 and maybe the 9mm M16.

Going back to the legal question in the US.  By attaching this to a glock, don't you have to SBR your pistol since the registered item has been converted from a pistol to a rifle (because of the stock).  ($200 tax stamp)

I was missing the 16 inch barrel part of the equation.  It makes sense to me.

Thanks.