Pintle exotic metal alloys. For World War II aircraft with sideways-retracting main gear units, carefully set-up "pintle angles" for such axes of rotation during retraction and extension allowed the maingear struts to be raked forward while fully extended for touchdown and better ground handling, while permitting retraction into rearwards-angled landing gear wells in their wings to usually clear the forward wing spar for stowing while in flight. Pintle A pintle is a pin or bolt, usually inserted into a gudgeon, which is used as part of a pivot or hinge. Other applications include pintle and lunette ring for towing, and pintle
Bolt action or "lugs", which serve to lock the bolt in place. The operation can be done via a rotating bolt, a lever, cam-action, locking piece, or a number of systems. Straight-pull designs have seen a great deal of use, though manual turn-bolt designs are what is most commonly thought of in reference to a bolt-action design due to the type ubiquity. As a result, the bolt-action term is often reserved for more modern types of rotating bolt-designs when talking about a specific weapon's type of action. However, both straight-pull and rotating bolt rifles are types of bolt-action rifles. Lever-action and pump-action