I would not shoot someone else's reloads. You have reason to be concerned. I have a friend that I shoot with sometimes. We both reload. I shoot mine. He shoots his. We do not share. I pour lead to make my own bullets. I have given him bullets to load for himself. But I have never loaded them for him.
Reloading is serious business. If I blow up my own gun because of my own carelessness that is bad. If I do it because of someone else's that is a different matter all together.
You are correct. Shoot what you load, or buy factory ammo.
Romans 1:16 I am not ashamed of the gospel, because it is the power of God for the salvation of everyone who believes: first for the Jew, then for the Gentile.