Using action threads to mount a barrel to a receiver typically requires fitting by a competent gunsmith, and typically some machining has to be done. Fine threaded systems intended for hand tightening typically use thread pitches around 1 mm (25.4 TPI).
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Many older rifles from the first half of the 20th century use a thread pitch around 2 mm (12.7 TPI), while many modern rifle use thread pitches around 1.5 mm (16.93 TPI). Typically, many rifles use thread diameters in the range between 25–27 mm (0.98–1.06 in). However, the use of action threads is not well standardized within the firearms industry, and threading can vary between manufacturers and models.įor example, factory and aftermarket receivers using the Remington 700 footprint are produced with various types of action threads, all with a 26.99 mm ( 1 + 1⁄ 16 in) diameter, but with a pitch of either a 1.588 mm (16 TPI, Remington standard), 1.411 mm (18 TPI) or 1.270 mm (20 TPI, Savage standard). Threading can be specified by diameter, pitch, angle, length and fit tolerances. There are many systems for designating thread types ( metric, unified, Whitworth, etc.).
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This design is most commonly used in rifles and revolvers, but also on some pistols and shotguns. The receiver normally has corresponding threads which are internal, with the matching action threads on the barrel usually being external threads. In firearms, barrel threads refer to the screw threads used to attach a barrel.Īction threads, also called receiver threads, are situated at the chamber end of the barrel, and can be used for attaching the barrel to the receiver. Method to attach a weapon barrel and receiver