Posting here as it isn't airsoft...

H&K SR9 in T configuration, low round count.  It has been a safe queen for the majority of it's life.   
Includes: H&K wide forearm with bipod, MSG90 butt-stock, port buffer w/ carry handle, claw mount, PSG grip, Williams trigger (2~2.5 lbs. pull), 10x 20 round magazines.



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Asking $3,500 American monies but will consider trades for a reduction in asking price.   Interested in Savage 10 FCM scout, Saiga 12 conversions, SCAR L.

uncomany.com is a good place to start.  What make and model?  If it's the actual SIG branded one than any marui style barrel will fit with the hopup unit, just go find a barrel cut to whatever length you desire.

Back from a trip to Japan, I have a very limited supply of these with both 14mm and -14mm threads.  $60 per or would consider a trade for KWA Mk23 mags.  I can meet at gearbox or leave it there for you to pick up.



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Depends on what your goals are.  If you're considering a career in military aviation I highly recommend it.  A good friend of mine is a captain in the USAF and graduated from there with his BSE in Aerospace Engineering.  Simply having Embry Riddle on his degree has opened many many doors for him from work at NASA Dryden to Flight School and a coveted slot at AFIT.  In the civilian world not so sure, I've got an Aerospace Engineering degree myself from a different university and haven't had terrible trouble finding work outside of the typical issues with the economic downturn and the defense industry.   There just aren't that many of us since most can't handle the program.  That said, you have to be willing to move where the work is and you've got to really want an engineering degree.  Like Terreus said, engineering doesn't ever get any easier.  My freshman class started with something like 250 in the program, by the time we got to graduation there were 5 left including myself.

A GBB shotgun with external operation to the Saiga would not be particularly difficult to construct from a mechanical standpoint.  Internally, the mechanism is already 80% there as evidenced by the existence of the Maruzen series and the more practical ACM M500 clones.  Some redesign would be required for the feed system in order to transition from a tubular magazine to a removable box but the problems there are trivial.  The more difficult problem would be designing a system of actuation for the bolt such that the pump action is no longer required.  Likely it would involve incorporation of the standard GBB rocket valve system or a double action system similar to NBBs.  I'd advocate for the NBB way of doing things personally due to the inherent mechanical reliability assuming the trigger wouldn't be more than a pound or two.  

As to barrels: Maruzen and ACM clone versions only use one.  They just chamber multiple rounds prior to expelling them.  This is desirable in a gas system where multiple barrels lead to multiple points of failure.

As to utility: any form of airsoft weapon utilizing a shell ejection system, irrespective of cool factor, is severely limited even in a CQB setting.  Multiple simultaneous shot weapons do however have their place in a CQB setting like Vanguard where fully automatic fire is restricted.  I have had particular success employing my ACM in conjunction with a secondary.  As  a primary I can deliver significant volume of fire over an AEG operating in semi, and there are certain psychological advantages held by the operator in employing the weapon against adversaries.  Further, the effect of multiple simultaneous impact of projectiles on the target increases probability of exceeding the sensitivity threshold required for registering a hit.  Obviously these utilities have significant diminishing returns with range.

Having said this, please do not go out and purchase a gas shotgun.  I enjoy being one of the few guys who run one and I don't want you scrubs appropriating my mojo.

Bumping again.

SOLD.