If you now have a 7.65mm and a 9mm cartridge, a visual inspection will tell you everything you need to know about which caliber it is. If it is 7.65mm (.30 Luger), the bullet will go into the muzzle as shown in the first photograph. The second round is a 9mm, and it won't come close to going into the muzzle as shown in the second photograph.
The only round you could get into trouble with is the 9mmKurz also known as the .380 ACP. It won't quite chamber in the 7.65mm chamber, but it is so close that the bullet could be driven back in the case if one is chambered by letting the toggle assembly go rather than easing it down.