STEVENS 87D, 1952: very bizarre mechanism of action in details.

This is a popular Gill gun, or Click- clack closed bolt semiautomatic rifle manufactured for many years by Stevens, Springfield, Savage and perhaps others. Model 87 with ‘d’ implies , I believe, 1952 year of production. Mechanism similar to the model 6 and different from any other semiautomatic rifle: In regular semiauto closed bolt mechanism, a pull of the trigger releases the hammer or striker, and the bolt cycles back and forth picking up and loading a new round for the next shot. Not this gun. It won,t allow the bolt to move forward after blow back, unless the trigger is released/ reset. This mechanism with 2 sears- one for the bolt and one for the striker works as a disconnect and also allows to slow down the bolt cycle not to outrun the feeding mechanism. I finally acquired this gun I have always wanted. It,s in perfect mechanical shape, works flawlessly, but could use some cosmetic work and more care. Please , enjoy.