I had a 100 rounds of new RP 300 RUM brass that I resized for my 338 Edge. Later on I picked up several boxes of ADG 338 Edge brass, so I resized the original brass back to 300 RUM. However, the shoulders are pushed back further than they should be. I've never fireformed with CoW, but want to give it a try to save costs and wear on a newer barrel. I've got some RL26 that I'm not using. What I've read with the CoW method; its add powder, toilet paper to separate powder from CoW and then a small cap of bar soap or wax. Question, how much RL26 powder would be a good starting point? Appreciate any suggestions to do this easier or safer. Thanks