RE: big mistake what to do
Well, you did the safe thing. But like the others have said it most likely wasn't enough to cause trouble but to loose $30 is better than loosing a gun and your eye if things did go wrong. The powder companies and reloading manuals all caution against mixing powders, even if like you are doing, emptying one can into another of the same type of powder, there are differences between lots of powder so even if it is the same powder from the same company the lots can and are different to some extent. So what I'm saying is it's not a great idea to mix powder, keep it in the original can.