Extractor Kits that fit Remington 783 and Marlin X7 in 223 as well as any of the cartridges it is the parent case of in the 223 specific bolt head.  These extractactors are manufactured and heat treated from 416 ss, with a hardened 440C ss ball, and a zinc-plated compression spring.  Kit will include (1 each) extractor, (1 each) ball, (1 each) zinc plated compression spring.  These are not the mim'd parts that come from the factory with these rifles listed, far superior extractor.