Either way... it's certainly not a DA/SA... doesn't really matter if you call it Double Action Only (this is really a misnomer and is generally only applied to firearms which can be ordered in DA/SA... Glock for example is known to be a striker fired DA, not DAO; yet it does not have second strike ability), Double Action or "Half Action".
There are really only two types of actions made for primer ignited firearms, the precise way in which the actions are executed should simply be viewed as details; all actions fit into one or both of the following two descriptions...
Single action: The pull of the trigger has only one action upon the firing mechanism of the firearm, and that is to release the energy in whatever form it may be which will strike the primer. (example: release of a fully cocked hammer) (typical open-bolt fully automatic weapons also fit into this description as do most closed bolt battle rifles)
Double action: The pull of the trigger has two actions upon the firing mechanism of the firearm; the first is to "cock" the firing device (or load the energy into it). The second is to release the energy. (example: cocking then release of the hammer)
Keep in mind we are talking about the actions the trigger has upon the hammer/striker... and with a "DAO" firearm, it is still Double Action. This would be like trying to create a new category for open bolt machine guns, called SA/Auto because hey... really only the initial depression of the trigger acts upon the firing mechanism; after that, the action operates without anymore interference from the trigger.
My point here is, as gun manufactures come out with new operating features, they throw a name at it and claim it as new and different. Good example is Glock... They call it "Glock Action"... well guess what, it's nothing more than a different take on double action (thank God striker fired pistols didn't end up being referred to as "glock action"). Trigger pulls the striker to the rear, then the trigger releases the striker: two actions. Now you have some pistols which were originally DA/SA, then offered in DA only, now offered in SA only... are we going to make up a new action type called SAO? Simply because it's a pistol originally designed as DA/SA? No, SAO would be the same as what DAO was originated as... simply a way to clearly differentiate the DA/SA version and the DA versions... because people are too stupid to read "Action: Double Action".... and understand that it's actually double action... not a misprint so they started having it say "Action: Double Action Only"... this was shortened to DAO
All the above BS comes down to one thing...
Just because a firearm will only fire at half-cock doesn't mean it's in a different category; if the trigger prepares the weapon to fire, AND fires the weapon... it's TWO actions... hence "double action".
