Yesterday I was at the Gun Shop in Waterbury and they had a shockwave in 20 gauge I’ve been looking for so I quickly nabbed it up. My question is there any legalities to putting a Sba3 brace on it ? I’ve been hearing mixed responses in other threads.

I recommend submitting a Form 1 and turning it into a proper short barreled shotgun with an actual stock.

Federally, you should be ok because it will be over the 26" minimum length. Federal law defines an SBS as
"(6) The term “short-barreled shotgun” means a shotgun having one or more barrels less than eighteen inches in length and any weapon made from a shotgun (whether by alteration, modification or otherwise) if such a weapon as modified has an overall length of less than twenty-six inches."

The shockwave gets around this by being just over the 26" minimum. CT doesn't really have restrictions on pump shotguns so there's no reason not to Form1 it and use an actual shotgun stock. An SBA3 will not be comfortable to shoot.

in the AFT's proposed pistol brace rules, it addresses a braced Shockwave or Tac14.  If the rules go into effect, the AFT will see it as a SBS.

Possible issue but the beauty is you can buy it and form 1 one it online and have an sbs in approximately 25 days! Buy it, do it! Brace is soooooo ghey

Yep. Anyone wanting to put a brace on a pistol grip shotgun like the Mossberg Shockwave should keep an eye on the status of that proposed brace rule. The language from that proposed rule:

I wonder if the AFT would require a state assault weapon cert for a pump SBS?

They do not. *source - me. I've done it.

They may/will ask for a cert but pump sg’s are not aw’s! I quoted ct law and sent the law to them, it was approved the same day.