Rock-Ola did make spring tub carbines but I was mistaken, this one does not appear to be a spring tub with a tab. 1668 is close to the cutoff between type 1 spring tub receivers and type 2 spring...
Type: Posts; User: Bubba-7; Excluded Forums: Milsurp Knowledge Libraries (READ ONLY)
Rock-Ola did make spring tub carbines but I was mistaken, this one does not appear to be a spring tub with a tab. 1668 is close to the cutoff between type 1 spring tub receivers and type 2 spring...
Early type 1 spring tube. You will have to fine a tube with a tab.