I’m disturbed by the number of times I come up with some idea to do with firearms. Anyway, today’s invention is an easier way to create a rifled bore ie without having to cut spiral grooves.
This involves driving a mandrel axially through a blank barrel. The barrel is then twisted around the central axis, to the point of slight plastic deformation, so as to distort the internal grooves into permanent helices.
The twistrate of these helices can be locally varied so as to optimise the rotational acceleration of the projectile being fired (ie as a function of the varying gas pressure behind it).