Howdy Gents, I have a quick ID question on the M407 series of 40MM low velocity grenades. The question is, what is the difference (if any) between the M407, the M407A1, and any other designation out there? I've seen some with solid plastic or steel fragballs, inert or live fuzes, some marked inert, some not marked either way... I've had the question asked a few times over the years, and thought of it myself many years ago. Also, as far as I know, the only way to tell if you have a live fuze is to shake it a bit and listen for the rattle of the fuze parts. No way to tell except by xray if it has a steel fragball. So, if anyone can help, mucho thanks! GROG