I recently purchased a M40-A1. I had a choice of either the M40 or the M40-A1. I went with the A1 because it was newer and held 12 rounds. I thought all A1's were made after 2010 but after reading on this forum I am finding out that this is not true. Is there a place to look up my serial # and find out when my gun was made? I am not the first owner of this gun.