A jug choke only has no effect on round ball accuraty supposedly if you shoot a patched round ball. If you shoot a bare ball, the accuracy will suffer considerably over what it was before the choke was cut.
I have found that the shot range, and pattern of my tradegun is better with 2F, than it is with 3F, and if I can get, my hands on 1F, it even better yet.
Hungry Horse