Lawmakers have reintroduced a bill that they say would ban so-called “ghost guns,” or guns that are made from a build-it-yourself kit, in their latest gun control effort. The measure, dubbed the Untraceable Firearms Act, would expand the federal law’s definition of “firearm” to include “ghost gun” parts such as unfinished frames and receivers. The move would require online and other gun kit manufacturers and distributors who sell such parts to comply with the same federal regulation that governs the production and distribution of completed firearms, such as requiring sellers to obtain a manufacturer’s license and to place a serial number on the frame or receiver included in each kit. Purchasers of such kits must also undergo a background check. Sen. Richard Blumenthal (D-Conn.) introduced the bill along with 11 co-sponsors during a Senate Judiciary Constitution Subcommittee hearing on Tuesday. Rep. David Cicilline (D-R.I.) introduced a companion bill in the House. A version of a similar bill was introduced …