Your question is not concrete enuff!
You maybe mean to put the JP223 on an A-10.
Not possible...you need an addon or to rewrite the .cfg (I'm not sure about the last?).
Or you mean that the Tornado is only using the JP223 (maybe if you tell it to).
Possible...
First way:
Remove all weapons and add the JP223 again.
The Tornado can only use this weapon because he has no other!
removeallweapons this; this addweapon "XXX"; this addmagazine "XXX"; this addmagazine "XXX"; -> one weapon two mags here
Second way:
Makes it "choose" and fire the named weapon.
Tornado Action ["weapon","XXX"] -> selects the weapon.
Tornado fire ["XXX","XXX"] -> fire weapon (two times here!)
You've to find the specific name for the weapon and the ammo you want to use (here "XXX").
Complecated enuff!?!
But maybe you ment something completely diffrent? ;D