This is one of the Saiga 12 Kushnapup guns we have done for clients.
Almost anyone can take a stock Saiga 12 and put it into a Kushnapup stock for about $235.00 and sell it for $1100.00 or thereabouts.

BUT if you want the finished product to shoot low brass ammo as well as it shoots high brass ammo, to be extremely reliable and with a smooth action and if you want a shorter gun but still legal so it is great for indoor home defense, then you need what we have done to this gun, done to yours.
Coming down the hall at night with a long shotgun and trying to turn around is not easy with the standard barrel length of 19" plus a 2" brake screwed onto the end of it.

When we build a gun we try to take into account how it will be used and make the necessary changes to optimize that gun for it's intended purpose. To that end we have done almost the same performance options that we have done on most of our other more expensive guns.

First, since this model uses a basic factory standard gun to start with, we pulled the Fire Control Group and replaced it with our US Made custom trigger that has been reshaped and polished and has also been milled out for an Over Travel Limiter that we install and tune to the gun. This gives you a shorter trigger pull and a faster reset. We also polished and re-profiled the bolt and carrier to improve smoothness as well as reliability and we buffed the rails. Next we jeweled the bottom of the carrier to hold oil better.
We then did our gas port work by enlarging all 4 ports and modifying the gas block itself as well. Then we installed a new, modified gas knob that works with the port work we just did as a Plain Jane after market gas knob will not function correctly. We changed the recoil spring and buffed out the rails as well. Everything done to enhance reliability and performance and making the gun a smoother gun to operate, charge, and shoot.
Then, since the whole point of a Bullpup is a shorter gun overall, we cut the barrel, re-threaded it and silver soldered on the Tromix Shark brake to give us a legal barrel length of approx. 18.5" instead of the 21" inches a stock barrel and brake would produce and an overall gun length of about 29.5 inches to the back of the butt pad, an inch shorter if a pad is not installed.
2.5" may not seem like a lot but it is very noticeable when the gun is in hand and especially in a hallway or other tight situation.
The Shark brake that we used also reduces felt recoil by approx. 15% and is noticeable.
We also drilled and tapped the gas block and added a top rail for a red dot (red dot optional extra) as the factory sights become useless in this style of Saiga 12ga.
With this rail you need a taller red dot such as an Eotech or a Burris FastFire on an AR Riser. We also have a taller rail that can be installed that sits about 1/2" higher but the one currently on the gun looks sleeker. You can see one of the taller rails on one of the refinished guns at the bottom of the pictures.
We then added an SGM butt pad to the rear.

To enhance the gun totally as to speed of usage, we installed a Competition MagWell that lets you insert the mags with no rock and lock. Just a smooth insert like with an AR. Then we modified the release so it is on the left side of the gun and takes but a tap to release the spent mag and with the same hand insert a new fully loaded one. You never even have to take the gun off your shoulder. The gun is a blast to shoot and runs most low brass as well as high brass ammo without a hiccup. We test these guns with Federal bulk pack birdshot and Spartan and RIO Low Recoil ammo.
For an independent review by one of our clients who bought the base version of this gun go here:

http://www.thetruthaboutguns.com/2014/12/daniel-zimmerman/gun-review-saiga-custom-kushnapup-2/