More info about the seal and cushion for 16ga
630 gr slug. Plastic seal works best.A clearer description
It is a BPGS type plastic seal, IE, a one way seal,
and a flex type cushion. One way seals best.The seal/cushion,
is the bottom part from 16ga wad cups.
Like bottom half of bottom trap commander 16ga wad.Ed


Ed Hubel