I apologize if this is a stupid question, I'm new to shooting. Anyways, I bought some Winchester 9mm Luger FMJ 115GR 100 round Value Pack's and I noticed on the brass, they read a number 10, instead of 9 like my other brand 9mm lugger ammo says and I'm just a bit confused. I compared the two, and they look pretty identical in size... so the "10" is throwing me off a bit. I'll get my coat... Wanna kill these ads? We can help!