@Powderburn, if you have a dial or Vernier caliper for inside measurements, take a reading of the cylinder mouth, a little deeper in the chamber and the groove to groove diameter of the barrel. Ideally the chamber diameter should be within 0.001" of the groove to groove diameter. You want a ball that properly fits the chamber and provides a seal between the powder and the ball. Some Euroarms revolvers have a rebated or stepped chamber with the mouth slight larger than than the chamber. Sometimes that will mean that a 0.380" ball is the right choice. Most of us strive for a ball slightly larger than the chamber mouth so that a ring of lead is shaved off in loading. That doesn't happen with a rebated chamber.
Since you do have a brass framed revolver, do keep the powder charges on the light side. Use Cream of Wheat (COW) or corn meal over the powder to fill the chamber to within about 3/8" from the mouth Powder can fillers do crush down so a bit more can be used.
Do get a good nipple wrench for revolvers as the clearance and nipple size are smaller than on rifles. Before going to the range, remove the nipples and use a grease such as RIG or a Never Seize grease so the nipples can be easily removed for cleaning. Take a look at the tip to see it the pistol has bee dry fired. Mushroomed nipples mean poor performance on the firing line. Needing two hammer falls is an indication of a mushroomed nipple. A mushroomed nipple can be filed down at the tip so caps can be loaded.
Like Gren says, we will take fifty lashes, and apologise profusely!
