I was givin a 20 ga. field grade,double with auto ejectors and 26"barrels in pretty good condition from my grandfather. It has a serial # of Fw70952. He used it alot for grouse hunting but hasnt been shot since about 1993. the gun is still very tight. I would like 2 use it again for grouse but wondering about todays new shells and if one is recommended over another.Also about what the w in the serial# means and judgeing by the info i looked up was the gun made in 1924 or 25 thanks for any info.