This is my first post and I am new to older guns. I inherited my grandfather's shotgun and I was told it was used in WW1. Using your site, which has been great, I was able to figure out some about what I have. The one issue has been one marking that I saw someone else ask about. The symbol is AB inside of a diamond. AB is also engraved on the barrel release. Can someone point me in the right direction of what I have. I want to be able to hand this down to my son one day and hopefully it will be handed down to my new grandson which will be here in July.