This Remington manufactured trigger spring plunger is for the model 550-1 semi-auto rimfire rifle and is in very good condition with light wear. (file photo)

Note: Model 550-1 rimfire rifles with the following date codes and years of manufacture have been observed with this part: (KUU) May 1949, (DUU) Sept 49, (EUU) Oct. 49, (CWW) Apr. 50, (EWW) October 1950, (LXX) February 1951, (LYY) February 1952, (RYY) Nov. 52, (PZZ) June 53, (LB) Feb. 55, (WB) Aug. 55 & (XD) Dec. 1957.