The Navy SEALs used a “duckbill” spreader to get a wider pattern when using shotguns for CQB in Vietnam. That design worked great but would fracture and fail after extended usage. Paradigm has revisited and improved the duckbill with 2 versions – one for the Saiga and one to replace the internal choke tube for over a dozen different shotgun models. The duckbill is door breech capable and should NOT be used with slugs or steel shot.
Go to www.paradigmsrp.com for the full scoop, some videos and their online store. MSRP as of this posting was $199 for either. While you’re there, take a look at their way cool Talon gyro-stabilized weapons mount.