Almost as good as banning military-style rifles would be to put a very large tax on them, such as 10 times the sales price.

This could be passed via budget reconciliation, avoiding the filibuster.

One weakness is that right-wing extremist billionaires, or states such as Texas, could defeat the purpose of the measure by paying the excise tax on behalf of the individual gun purchasers. Better make the tax 100 times the sales price.

The state government of Texas protects gun companies from pressure by boycotting companies (such as banks) that boycott them.

I like the solution of having California boycott the banks that fail to boycott gun companies, because it uses for the cause of life the same instrument that Texas uses for the cause of death.