I think the 2 d's is about all my area will allow, I would need a lot more room to go bigger than that. The D's will fint in these tubes with one layer of cardboard peeled off of them. The tubes are quite a bit bigger than they needed to be to hold the a's, b's and c's.

I am going to see if my brother-in-law will film it today or tonight. It is really pretty cool at night. But they do have a really short burn, as any of you who play with model rockets already know.