the cylinder further the chamber 28 need not be oriented perpendicular to the keyway as shown in fig2 and 3 for example see fig4 in which the orientation of the chamber intersects a portion of the keyway in a non orthogonal angle u00f8 it is preferred that the orientation of the chamber be angularly inclined an angle u00f8 in the range of about 45 degrees to about 135 degrees with respect to the plane of the keyway with this different orientation of the chamber as shown in fig4 the key receptacles are located on the opposite side of the key on the upper key groove 46 as shown in fig6 a plurality of chambers 28 are preferably utilized in the cylinder plug 20 of the pin tumbler cylinder 10 and which are uniformly laterally spaced on intervals of the ball bearing radius or larger in the direction of the cylinder axis on either side of the keyway the shell cavity 54 is preferably sized to have a diameter equal to or greater than the diameter of the ball bearings the cavity may preferably be dish shaped or arced as shown in fig2 in discrete locations or along the entire length of the shell the cavity may also be a cast broached drilled or milled hole as shown in fig7 a 7c and which is aligned with the bottom edge of the chamber when in the locked position the invention also provides.