76mm Smoke Bulkhead with 3/8-16 head bolt and smoke grain retaining ring.
A retaining ring holds a 1.875" x 1.25" smoke graiin. Has a 3/8-16 threaded attachment point which comes plugged with a head bolt and o-ring. A hole behind the head bolt allows for wire pass thru enabling head end ignition. Low profile design takes up only 1.125" leaving more room for propellant loading.
Is capable of "experimental" (but proven) head-end ignition with a modified smoke grain.
The liner shoulder incorporates a liner sealing o-ring acting the same as a seal disk found in other brands. This is designed for use strictly with convolute phenolic liners. Spiral wound liners must not use this o-ring.