
146 Ballistics: Theory and Design of Guns and Ammunition
Problem 6
A 155 mm projectile is red from a tube with a 1 in 20 twist. Its muzzle velocity is 1000m/s.
What is the spin rate at the muzzle in Hz?
Answer: 322.6 [Hz]
Problem 7
It is requested that a brass slip ring be constructed for a spin test xture to allow elec-
trical signals to be passed (although real noisy) to some instrumentation. The design
requirements are for the ring to have an ID of 4 in., a length of 2 in., and be capable of
supporting itself during a 150 Hz spin test. How thick does the ring have to be? The
properties of brass are as follows: yield strength of 15,000 psi and ...