Goat. Years ago, we used to test unknown ammo for corrosiveness by a very simple method. If you can find an old steel razor blade, stainless won't work, pull a bullet. dump the powder, and fire the primed casing in your rifle with the muzzle pointed at the razor blade. You have to be reasl close to the blade so the gases will hit it. If you can't find a razor blade of the proper type, go to a metals place and see if you can get a scrap of clean iron or steel. Polish it up a bit, or sandpaper any crud that might be on it. Use that in place of the razor blade. Clean your gun with the proper method used for corrosive priming, and oil the bore afterward. WD-40 works well for this.
Place the metal you fired the primer at aside. If you are in a high humidity area, rust should form overnight. In drier climates, it might take a few days. If rust forms, the primers are corrosive. You might want to fire several primers at the steel to insure you contaminate it properly.
Hope this helps.
Paul B.