Be equipping “Saiga 410” with Paradox muzzle choke you will extend confident firing distance (up to 300 m) and improve accuracy since projectile via choke rifling will get rotation and therefore better stability.
Choke manufactured using precise forging with barrel steel adapter. To improve performance, durability and corrosion resistance internal surfaces are hard-chromed with layer thickness 0.01 mm. Externally choke protected by chemical blue and phosphate coating film, paint and laquers.
For easy installation chock knurled and have chamfer for key. Part with rifling has 15 cm length, what limited by law. Rifling is progressive, i.e. filler of screw and threads height getting bigger towards the end. By this projectile accelerates and twists progressive, but smooth. Also it unload barrel and eliminate projectile slip possibility.
For decent shot you will need special 410 gauge slugs, heavy, accurate, with 2 or 3 flanges etc. Slug engraves in rifling only by these flanges, not the whole surface, what saves load energy.
As any gun after firing it require cleaning, including barrel thread and Paradox muzzle choke. Then you should lubricate threads, gun oil will work fine.
Also after every 15 to 20 shot you should unscrew chock and install in back, to remove threads strain which grows with each shot since slug, engraving through rifling, impart moment along the threads and after half a hundred shots chock unscrewing will become an issue.
To effective hit target located farther than firing range of typical smooth-bore shotgun you will need to choose proper slugs and have high quality barrel and choke.
With Paradox 410 and proper scope, red-dot for instance, ordinary Saiga 410 will become competitive of accuracy and power with rifle.
Length: 150 mm
Thread diameter and pitch: 15 mm x 0.75