12 gauge whisper?
 

I bumped into this last night

http://www.saddleryandgunroom.co.uk/..._Hushpower.htm

So, why not a suppressor for a rifled slug gun with a subsonic load?

Has anyone tried this? Opinions appreciated.

personally I think there design with scrape off a lot of wadding. I have worked on shotgun suppressor designs with a someone I know. learned a lot on the designing the stack to keep from shaving the wad and preventing it from starting to open before exiting........

on a side note........a over and under suppressed would be cool.

There are a few people making shotgun suppressors. Silencertalk has several threads about them.

I have been playing with the idea of a form 1 integral 12G TC Encore
with the slug barrel.

while a pump action would be more practical, the over and under is kinda cool............a intergal design for my SBS would be sweet so I can keep it at 14.5" barrel length.

That is a good idea as well. Let us know if you go through with it, and are generous enough to share the design.