I have a soft spot for single shot rifles also. I have a model 40. The twist is 1-14" - a little too slow for 55 grain bullets. As far as powder - try W296 or H 110 with light bullets (35 grains and under). Try some Lil'Gun with the 40 - 50 grain bullets. I have not had very good luck with it (erratic), but others have and it gets higher velocity than other powders with 40 grain bullets and above. There are other powders that work in the 22 hornet like 2400 and H4227 to name a couple. The scope you mentioned is a good one, I have a Mueller APV on mine and am satisfied with it. It costs considerably less than the Leupold - $115 shipped and has an AO, down to 10 feet if you want. But like I said the Leupold is a great scope. If you get back to the shop, work the action. On mine it was not that smooth, I have done some work on it and it is better, but still not as smooth as 2 Stevens or Remington 700 I have, for that matter a couple of rim fire bolt actions I have. I do not know if they are all like that or just mine. I say work the action and pay particular attention to the smoothness to see if it suits you. Mine feels draggy with a cartridge or not. Another thing I do not like about the model 40 is that bullets need to seated pretty far in to work through the action, so far back, they will not come close to the rifling. You can seat them out further being a single shot, but if you do not fire it and want to unload you will not be able to. The case head hits the ejector (which is fixed in the bottom of the action) and will not clear the opening. Making getting it out a real difficult time. I really like the looks and feel of the model 40 and it shoots good despite not seating the bullet out very far. Unless you need to keep the noise down, you might consider a Stevens 200 in 223. It would handle the 55 grain bullets with ease (1-9" twist rate). The stock is not as good and the finish is not as good as a model 40 either, but I think the action is better, you get as much accuracy if not more and it costs very little more to reload for than a 22 Hornet, maybe less, depending on how hot you load the Hornet. You can swap out the stock if you do not like it and have about the same amount of money in it as the model 40. Another route is a CZ in 22 Hornet - more money, but I think it a much better rifle. The only thing I do not like about the CZ's are the trigger guards - chintzy looking - functional, but just cheap looking. Good Luck and Good Shooting