As my username suggests, I am new to the world of airguns, having used only shotguns all my life, with the possible exception of a Webley junior when young. I have been given a .177 air pistol which I now know is a BSF S20 in very good condition. I understand that they were made between 1950 and 1985. My question is, can the precise date of manufacture be established from the serial number? Would it be of interest to a collector. Also have been given a 'Gem' air rifle in fair condition which I believe is again German made about 80 to 100 years ago but I stand to be corrected on this.
Any information that anyone could give me on these would be greatly appreciated.
There is also a Relum Tornado in good condition, made in Hungary which probably is not worth a great deal but seems fairly powerful. Would this be any use against rabbits and pigeons ?

Many thanks for any help given.