State Sen. Floyd Prozanski, a Eugene Democrat who represents north Douglas County, has seen gun bills repeatedly introduced and fail in his two decades as a lawmaker. This year, however, could be different, he says, with heightened concern about gun violence and Democrats in the majority in both chambers. As chairman of the Senate Judiciary Committee, Prozanski holds sway over which gun-related bills will receive hearings. He said proposed bans on assault-style weapons and high-capacity ammunition magazines already have been scrapped, left up to the federal government to impose. But a quartet of bills that Prozanski calls “common sense” are …