I have a Walther 9mm Ultra that has been sitting in my safe since 1985, it is unfired by me. Never had any ammo for it, but picked up a box last weekend at a local gun show. I pulled one of the 100gr bullets and it mic'ed out at .355. This is the same as the .380 round, two questions; can you fire .380 ammo in it, if not, what is the difference in the two cartridges? Anybody have one of these shooters? How do you load for it.