The Burney EM-4, also referred to as the Broadway Trust Rifle, is a British "recoilless" rifle.
The Burney was conceived in 1944 along with a few other Experimental Model designs, such as Korsak's, Jesieranski's, Metcalf's and Hall's. It was designed by Dennistoun Burney of the Broadway Trust company. 7mm and 20mm variants were made, but little else is known about the history of the rifle.
The Burney had an enlarged chamber that the gases from the bullet expanded into and were then exhausted through the barrel after the bullet had left, technically making it "recoilless".