Yes, the whole barrel slides back on rails as does the breach block.
There are two sets of springs. One recoil spring and one breach block return spring. The recoil spring is under the forestock. The breach block spring is in the buttstock.
The barrel has a lug that slides along the magizine tube. The recoil spring goes between the barrel lug and receiver. The forestock controls how far the barrel returns.
The breach block has a long link attached to it the extends to the rear and rest against the breach return spring.
When fired, the barrel slides back being controlled by two things, the recoil spring and a friction braking system that consists of a bronze friction ring and a concaved spacer. This system is used to setup for heavy or light loads.
The barrel sliding back compresses the recoil spring and the farther it slides back, the more braking there is from the bronze ring.
Plus, the breach block link starts compressing the breach return spring.
If the there is not another shell to load, the breach block will lock open.
The video shoes what happens when there is a shell to load.
The barrel lug facing the receiver is concaved. The spacer has a flat side and a concaved side. The bronze friction ring has a rounded end and a flat end. The rounded end of the bronze friction goes toward the concave face of the barrel lug. The flat end of the bronze friction ring rest against the recoil spring. The other end of the recoil spring rest against the receiver. There is also a c type spring around the bronze friction ring to give some static friction. Both the spring and bronze friction ring have a opening allows them to be squeezed together.....think of the letter c.
When fired, as the barrel slides back, the round end of the bronze friction ring, being against the concaved face of the barrel mag,lug causes the friction ring to be squeezed against the mag tube, increasing the friction and controlling the amount of recoil along with the recoil spring. This is the setup for light loads.
For heavy loads, the concaved spacer is used. The spacer is place between the recoil spring and bronze friction ring with the concaved side of the spacer facing the flat side of the friction ring. The friction ring now will be squeezed from both ends instead of one, creating more friction braking, reducing recoil of heavy loads.
The barrel extension, the part that slides in and out of the reciever needs to be flush with the end of the opening of receiver housing. This is controlled by the forestock. If the barrel extension is not flush, the direction the barrel extension needs to be moved to be flush is controlled by which end of the forestock material is removed from.
If the barrel extension comes out to far, the the reciever end of the forestock needs some material removed. If the barrel extension does not come out far enough, some material from where the barrel lug rests against the forestock needs removed.
The reason the barrel and breach block move back together is that there is a locking lug on the breach block the extends into a opening on the inside of the barrel extension, locking the two together. After reaching a certain point back, the locking lug releases from the barrel, and the breach bolts gets locked back allowing the barrel only to move forward.
The breach block will be released at the proper time during the loading cycle of another shell. None to load, stays locked back.
Before removing the barrel, lock the breach bolt back.
All this in the 1900.......John Browning was the man.
In Thunderball, that is a Browning Auto5 Bond uses to shoot the clay.
