A big improvement over most any rifle maker out there, would be to chamber LOTS of different cartridges. I always wondered why a big company like Winchester didn't offer anymore calibers than the other makes on the market. Tooling costs aren't that huge for different chamberings. EDM machining could be used to make very nice barrels and receivers. Even fancy full-length ribbed barrels would be no problem.
Aside from that, a nice new single-shot rifle design would be most welcome.