
141Ammunition Design Practice
Now let us look at the axial stress. This is the stress at the point due to two things: the axial
inertia of all the material ahead of the cut setting back and the effective internal pressure
caused by the rotation of the projectile and the hydrostatic compression of the ll material:
zz
pr pr
rr
F
=
−
−
()
−
−
ii oo
oi
Axial
22
22
π
(4.102)
zz
We shall use the radii given in the problem statement. We put negative sign in the afore-
mentioned equation to denote compressive stress because only the axial component loads
the inner wall in compression. The force acting on the section of interest due to setback is
given ...