If you build it stock, you can fly it with the C-11, D-12, and Aerotech 24/40 case and reloads ( E and F ), as well as most single use composite motors.
You could fly it with an E motor with the motor hanging out the back, past the engine hook. You would need to tape the engine to prevent it from ejecting, and check for stability, since you are shifting the CG further rearward. Explained with pictures here:
https://www.apogeerockets.com/education/downloads/Newsletter415.pdf
If you change the engine hook and motor tube to accommodate the longer E-9 and E-12 black powder motors, you can still fly the aforementioned motors with a 1" orange adapter (included with many Estes kits), or cut a 1" section from a spent 24mm motor casing. You would need a 3.75" long hook, often called an "E" engine hook, and BT-50 tubing for the motor tube at least 3.75" long. And, of course, you would have to check for stability and possibly add more nose weight. If I'm using an engine hook I like to also glue in a thrust ring (engine block) above it so that the engine thrust on the front end of the hook does not put undue stress on the slit in the motor tube where the hook enters.
Alternatively, you could ditch all engine hooks and install a screw on retainer. No thrust ring needed, however if flying BP motors you need to wrap a thin strip of masking tape to the end to act as an aft thrust block. Composite motors have a rear flange molded into the case.
The ditching of the thrust ring is a more common practice in 29mm motor mounts, where engine casings have a greater diversity in length. A thrust ring will limit the length of engines that you can fly.
When comtemplating using non-recommended motors, Open Rocket and RocSim are your friends. They allow you to simulate flying with these motors and what the result will be: speed off the launch rod, maximum apogee, when in the flight profile the ejection happens, success or crash. OR is free.
). I was referred to Chris M's (@hcmbanjo) method of making the paper transition at the base stronger, and may go with thru-wall fins as well, and reinforcement to those oblique Body tube joints. Hence some projected altitude will be lost to mass. I've always been a fan of generous fillets, etc.
