Trace,
Venry has built an Open gun in 357 Sig if I recall. Too, Johnny Lim has his 9 Limcat (I think that's what he called it). It's totally doable and not difficult. Feed issues will be fine with normal care, but I think I'd want to check with those that are more experienced with it to confirm. I'd PM Venry or call Johnny.
Rich
ETA: Don't forget that it wasn't too long ago folks were running open guns in 9X25. Worked, for a little bit, for that TGO guy, so it is possible. Barrel, is a barrel, is a barrel. On getting one, I'd think to call Bar-Sto first as cutting barrels in whatever caliber is cake for them.