This Remington manufactured first variation 24" long barrel with the early barrel markings is for the model 550-1 semi-auto rimfire rifle in 22 S, L & LR caliber and is in very good condition exhibiting a mixture of thinning original blue finish blending with a brownish gray patina and having some specks of surface rust. The bore is bright and rates excellent. (file photo)

Note: Model 550-1 rimfire rifles with the following date codes and years of manufacture have been observed with this part: (OTT) July 1948, (KUU) May 1949, (DUU) Sept 49, (EUU) Oct. 49, (RUU) Nov. 49, (CWW) Apr. 50, (EWW) October 1950, (LXX) February 1951, (WXX) August 1951, (RYY) Nov. 52, (PZZ) June 53 & (CA) April 54.