This Remington manufactured third variation breech block assembly is for the model 12 slide action rimfire rifle in 22 S, L & LR caliber and is in very good condition with light wear and some specks of rust staining. This breech block assembly consists of the third variation breech block (with the narrow locking block on the upper front section), round type (late variation) firing pin assembly and the late variation extractor assembly.  (file photo)

Note: Remington model 12 takedown slide action rimfire rifles with the following serial numbers have been observed with this part: 

12-A: 741138 & 802984

12-C: 663586