Should I build 12" or 16" AR?

[Bonas]

Unless you already have an SBRed lower, with the ATF basically banning braced pistols now, I'd go with a pinned and welded 14.5" at this point. Otherwise, you're going to have to register an SBR for any configuration useful for hunting. I don't see 16" as much of an advantage. I'd bump up to 18" or more once I'm past 14.5".