I believe the HTI motors will do quite nice if you run them on 12-14.4v and possibly 18v if you gear the weapon enough and share the load between two motors. Ive seen a few of them smoke at 24v, mainly in Hellbringer X (Aussie Rambot with 4 x HTI motors with SS2 gearboxes on 24v powered by 3600mAh Battlepack)