Is this a new barrel or the one you got when you bought it?
JUST KIDDING with y'allI'm sorry to disappoint you but they are not SBR's.
The XP's and the HSP's are designated as Handguns.
These center-grip pistols are not set up with arm braces or buttstocks.
I get it, you don't like specialty Pistols. There's nothing wrong with that.