New and unique improvements of prior known M4/M16 firearms are disclosed that comprise (A) a bolt which, in addition to all of the normal M4/M16 features is configured or reconfigured to accept a bridged extractor spring which straddles the firing pin and presses against the bottom of the extractor with the bridging wire, and (B) a bridged extractor spring which is a single part, wound with dual spaced helical coils connected with a bridge wire that maintains the spacing at the top of the spring. The bridge wire preferably crosses diagonally between and is tangent to both coils.