The nomenclature is incorrect but the fact is some air rifles easily shoot at 1200fps. I would consider a scumbag pointing a locked and loaded (and pumped), air pistol to my head every bit as deadly as any other "accurately" defined firearm.
The phrase "BB" gun is also very outdated from a technical aspect too. A classic Daisy Red Ryder (spring cocked lever action) BB gun (circa 1970), is hardly as lethal as some of today's modern air pistols.
The world has changed; re-defining things is part of that.
Time to start stockpiling air gun ammo before it sells out!!!