I recently was given my Great Uncles H and R, Model 904, 9 shot revolver. Its in great shape. Is there anyway to figure out its age? I also didnt know if anyone had any tips on shooting it. I shot about 200 rounds last night, and I was not very happy with the results. Based on everything I've read, I can only blame myself but figured I'd ask. More interested in history of gun. Last 4 digits of serial# are 5419. Thanks in advance for any help