Ah, okay, that makes more sense...just be sure to account for any masses that could have significant setback forces.
It would be in these, the back-halves of the finned projectiles. It would be in the channel where the fuse runs. Reamed out a bit at the top for a 209 shotshell primer, and then some sort of firing pin in the fuse hole. With the back sealed up to keep it from falling out, or from the lift charge pushing the pin forward on firing either. Over the 209 shotshell primer would be a small dab of BP as a burst charge to spread the chalk.
Such a design wouldn't be all that "drop safe", but should be foolproof on actual firing unless the 209 somehow managed to work it's way down a channel smaller than it is to strike the pin. My main concerns would be more towards it NOT working, that the mass of whatever kind of pin you could fit in there wouldn't be sufficient, nor have enough travel distance to strike the primer hard enough on impact.
Found it:
(C) rocket having a propellent
charge of more than four ounces,
(D) missile having an explosive or
incendiary charge of more than one-quarter ounce
So the rocket assisted munitions would be kosher if payload was <= 1/4th oz and propellent was <= 4 ounces.
I am missing something, or is the TYPE of payload and propellent not specified?
Yeah, this is what I'm struggling with too. I've bounced similar questions around on Grog's board, but IMO, he tends to be a bit too conservative on his determinations of DD stuff. The responses I got were unclear, and kind of "count it all" propellant and explosive towards the DD total.
I didn't agree, but it's his house and I'm not going to make a stink there.
I'm not all that concerned with making "offensive" rocket boosted loads that require a DD'd launcher, because I figure if it really requires being shot at "in anger" it would either take a round that's individually DD'able, or there's lots of better things in my arsenal I ought be using. Or the launcher would be better used shooting OC or CS which aren't DD, and don't require a DD launcher either.
I'm interested in rocket boosted projectiles, because I want pyro that goes high enough that I don't have to worry about flares or stars touching the ground before they extinguish themselves. Or chalk rounds that shoot fast enough, and flat enough I can use them at my gun club and not have to be worried shooting under the sky-blocking baffles would put them in the dirt before they even went 100 yards.