It occurs to me that you could make a Home Depot run this morning collecting all of the parts to make four ZIP guns, assemble them; tell your mother-in-law she can make an extra $800 for Christmas shopping, all’s she needs to do is drop these pipe fittings off at the location of the gun buyback. ;-)
Sending MIL very funny LOL, LOL!!!
Watch the movie “American Guerrilla in the Philippines”(1950). It shows how to make a slam fire shotgun.
Then hit the hardware stores for the parts.
Adios Mama!