I just have the sweetest wife alive.
She supports me as I play gun-building house hubby.
Believe it or not, these are legal in CA because they are not considered to be shoulder fired rifles and therefore not covered by the AW laws. I've seen guys convert bolt action .50 cal BMG rifles to spade grips, thus eliminating the stock and shoulder fire capacity... then the .50cal is perfectly legal. Guess they only banned shoulder fired .50 cal rifles; not the cartridge, itself.
A fully transferrable FA 1919A4 will cost you between $12,000-$15,000. Ludicrous! I did this more for the fun of the build and the challenge of the project. "Can I do this?" "Is this ever going to work?" I like that.