you want to take a trandohudarmsmesh and make it look like a turretanimation right?
link the trandohudarms(i'd take dc15s) up with the animationset of a turret.take an invisible texture and put it in the animationbrowser instead of the texture of the weapon.
now you got hands with correct animations but the turret itself is missing.
make an emitter(make a subclass of emitter in actorbrowser) of the object you want to attach to the animation. give it a staticmesh ( in your case mesh as turrets are meshes) and set its drawtype to dt_mesh or dt_staticmesh(depending on whether you want to attach a staticmesh or mesh). then go to the animationbrowser. select an animation where you want the object to appear. because your turret should be there at the beginning we attach it early at the first animation of the turret you see. thats the animation "load". select it.
go to notify(its at the right side of the browser).
add a notify and make it animnotify_effect.
select a notifyframe which sets the time when the object appears. as i said it should be quite early as you dont want to attach the object in the middle of the animation. take 0.0001 or something like that.
as effectclass you should use the emitter you have made.
set attach to true.
select a bone where you want your object to appear. (weaponattach_r for example. you'll got to test which bone fits best.)
thats the short-form. sorry its not a really good explanation. i wanted to make a tutorial with pictures etc for it and its half finished but im quite busy atm, srry. btw with that way i've made droid hud arms.