I am patiently waiting for MSAR to make good on the MCS, but is there a more ideal design for a pistol cal rifle.  Nice and short.  I purchased a stack of glock 9mm and 45 stick mags in case anyone does build my dream gun.  Seems Keltec could make a nice sub 2000 replacement in a bullpup.  DROOOOOOL!!!!!

I bought a Glock 21SF and a ton of G21 mags (including the Kriss 30rnd) when the MCS was first announced in 2008.  I have since sold all of it, since I seriously doubt we will EVER see the MSAR MCS.  

There is no bullpup that uses Glock magazines.  The Beretta Storm is the closest thing to a pistol caliber bullpup there is.  There are 16 round aftermarket extensions for the .45 version.

Who knows... maybe one of these days, Ratworx will buy out MSAR.  

Yeah, a bullpup in a pistol caliber would be awesome.
Don't expect anything from MSAR. I've been on the pistol carbine waiting list for years.
Supposedly, a company's making a 22LR adapter for the PS90. That is a definite purchase for me, should it come out.

You can always turn a Glock into an SBR by adding a stock. Not a bullpup, but it would be very compact and you can use your Glock mags.

http://www.zahal.org/products/tactical-stock-for-glock-jericho-941-handguns

http://www.endotactical.com/

http://practical-defense.com/products/h-e-r-a-glock-carbine-conversion-stock.html

Don't forget the Roni Pistol Carbine Convertion from CAA. I think that they are making a 16" carbine too.

The Steyr Aug 9mm para has no issues with a pistol mag sticking out behind the grip- it is no different than a rifle with an AR-15 mag behind the grip, just a bit thinner in profile.

Wow that makes no sense at all. The mag would not interfere at all. A side mag would interfere more that far back.

I'm on that MCS list as well, and I dont think we will ever see it.........but I would love to have a 9mm/.45 bullpup as well

Wow, that makes no sense at all.  A long mag like the Glock 33 rounders could interfere with your arm depending on your prefered length of pull, whereas a right-hand Sten type setup is completely out of the way.

I would like to see a 9mm version of the PS90.  
But, since FN has never made a P90 in 9mm, or shown any inclination to, I have virtually no hope of ever seeing one.

You understand we are talking about bullpups, right?  Have you handled or shot a bullpup rifle before?  I can assure you that the vertically inserted magazine in no way interferes with your grip or length of pull on a bullpup, but a magazine protruding out the left side of the stock would basically have to poke through your chest wall or the side of your face.  And protruding out the right side of the gun  the only way to reload would be to either reach over the top of the stock and extend your arm as far as it can go (basically crossing your arms in a very ugainly fashion) or reach under the stock and your own right arm and do the same thing.

With the current setup you simply reach down and pull out/insert- no different than an AR or AK except you reach a bit behind your grip hand instead of in front.

Maybe you have come up with some amazing idea here that we are all missing, but we need a sketch of something to understand because it is apparent no one here is on the same page.

Guess you've never held a gun. Your right arm does not go underneath the rifle to grab the pistol grip.It is off the the right side. I've shot AUGs with 42 round mags which are pretty long and did not notice it at all. The only problem I could see is a monopod like effect if you were to shoot it prone.