For out at my buddy's ranch. got several M80 size ones.
If ya wanna big bang.
Step it up to schedule 80 and run a piece of 1/2 inch all thread up the middle and bolt the caps on, use thick fender washers or steel plate under the nuts.
Otherwise, it'll just blow a cap off.
Don't transport them, just build them and blow um, ATF might get interested in them.