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 bolt, to turn and open the chamber. The entire reloading sequence was a more complex procedure than later designs, however, as the firing pin had to be independently primed and activated, and the lever was only used to move the bolt. Bolt-action firearms can theoretically achieve higher muzzle velocity and therefore have more accuracy than semi-automatic rifles because of the way the barrel is sealed. In a semi-automatic rifle, some of the energy from the charge is directed towards ejecting the spent shell and loading a new cartridge into the chamber. In a bolt action, the shooter performs this action