Sen. Dianne Feinstein (D-Calif.) stands next to a display of assault weapons during a January news conference on Capitol Hill. (Alex Wong/Getty Images)

Senate Democrats are preparing to move ahead with consideration of several proposals to limit gun violence, but prospects for the controversial ban on hundreds of specific weapons and parts are diminishing, according to lawmakers and aides familiar with the process.

Sen. Dianne Feinstein (D-Calif.), the chief sponsor of the ban, said Tuesday that her proposal won't be included as part of a bill encompassing several proposals that the Senate Judiciary Committee approved last week and that the Senate is expected to begin debating when it returns from a two-week recess in early April.