I went the same route - looked, shopped, wrestled with a bunch of decisions and even ended up with a heavy Handi Hornet, which I never shot. I ended up with a .223 Youth Synthetic Handi and decided it was more practical for me because I already shoot and load for the .223 and can take it to Hornet levels if needed but can't take a Hornet to .223 levels if needed.
Mine is 1:12, but if it had been 1:9, I still would have tried it. I shoot 50 grain cast RDOs with starting loads of Unique and W231 - (and lower). I get very good accracy at 10, 25 and 50 yards but have not finished load development. What I have done so far convinces me I will get tiny clusters at 50. Once I achieve that I will back it up to 100 and see if I have to develop further. The one problem I have is that I have the rear sight as high as it will go, plus hanging over the front edge of the base, so I have acquired a shorter front sight. Had a scope on it long enough to try some Federal ball and it printed five at a shade over an inch at 100 yards. Looks like I can go either way with this one.
My goal is the best accuracy I can possibly get with one of the two mentioned powders or 2400. There may be "better" powders but these are the ones I have because of their broad flexibility, especially Unique and 2400. Whatever the velocity ends up at is what it will be. Anything between 1600 to 2000 fps will be fine as long as the accuracy is best. It's a sweet little Hornet wannabe that can be a .223 if necessary but I have a .223 bolt gun I use for jacketed bullets to top velocities/flatter trajectories. Seems llike I rarely need that. The last coyote I took was trotting toward me at 100 yards, so the pedestrian cast-bullet loads from the Handi would have been fine. The shot placement with the 60 grain HP starting at 3000 fps would have been fine for a 50 grain flat nose at 1800 fps.
I shot these cast bullets in a 1:9 CZ (my jacketed-bullet .22 CF) and they did ok. I could have worked up a reasonable load in that but the Handi just took to the reduced-velocity cast so well, I didn't see a need to mess with th CZ further. Not that the 1:9 wouldn't work - it was just so much easier to get them to work in the 1:12, so why mess with it when I could keep it zeroed for .223 loads and the Handi zeroed for Hornet-level loads.
It's worth the development effort in the light little Handi. It's so............ handy and while 1600 fps doesn't seem like a lot those 50 grain flat noses whack steel with significantly more authority than a .22 LR. Even with the crazy market, I do see .223 brass for sale in the form of once-fired surplus, whereas Hornet brass was not sitting around just everywhere before the madness and wasn't cheap either. For my cast loads, I use separate brass and have no idea how many loadings I have run through them.
Once the cases have been fireformed to the chamber, I neck size only with a LEE collet die - with which you can adjust neck tension so as not to squeaze your bullet down below its optimum diameter for your throat/barrel. No crimp and the neck bell left in place - just enough that it still chambers. I use just enough powder to cause the brass to seal the chamber and prevent primers from backing out. Drilling the flash hole a bit larger helps with that too. Once I don't have soot on the cases, I work up from there.
I know you didn't ask for all that, but my .223 Handi is my "Hornet." If you weren't the one dropping the cartridge in the chamber, the report wouldn't give it away. It's not as nostalgic as the Hornet but the .223 isn't so much bigger that it's that much less efficient and seems to respond well to reduced loads. Now that I have been shooting it, I'm glad I went with the .223 instead of the Hornet. Nothing against he Hornet - it's just very convenient to use the .223.