Here is the language from my state's DNR reg's:
Primitive Weapons
For special primitive weapons seasons, primitive weapons include bow and arrow, crossbows and muzzleloading shotguns of twenty gauge or larger, and rifles of .36 caliber or larger with open or peep sights or scopes, which use black powder or a black powder substitute that does not contain nitrocellulose or nitro-glycerin components as the propellant charge. There are no restrictions on ignition systems including flintstone, percussion cap, shotgun primer, disk, or electronic. During primitive weapons season, no revolving rifles are permitted (50-11-310).
So it looks like I can use my system as long as the blanks don't contain smokeless. I could make up my own using BP or substitute. But I think there is a detonation risk since the powder column would not be in compression. It looks like this is a hunting bust but might make an interesting range gun.
Thanks,
Bob