If you get it figured out let me know. My plan was a single stacked magazine of some kind as far forward as possible, with a guide lip of some kind similar to the model 70 that overlaps the action’s feed ramp to help the cartridge get as far into the chamber as possible before it’s on its own. The pre-64 Winchester model 70 also had fingers on the bolt that helped push on the cartridge and get it up where it needed to be, that retracted up as the bolt reached the chamber. Obviously the 700 is not a control round feed, but there are some nuggets of wisdom in how they did it. The space required by the Remington extractor is not helping and perhaps a coned face bolt and different style of extractor would help minimize clearances that the cartridge would otherwise have to traverse. Would a coned bolt face require retractable fingers - I’m guessing it would.Thanks I did get a 22-250 chambered in 221 fireball and it works well