I have a F25 that is a beautiful gun but I don't shoot it enough because the stock was cut down to 13.5 LOP. MFG approximately 1917 in Birmingham. Started looking at a D grade and on the surface I can't see what makes it a D grade and what makes the F grade. I believe my F grade is based on the Facile Princeps box lock design but not sure of the D grade. I'm sure there is a simply answer but I need to learn it.

Nothing is foolproof to a sufficiently talented fool.