I have loaded Magpro in my 270 WSM and 7mm Rem mag using WLRM primers. I looked at the Accurate Arms Power web site and found some interesting things. They used a different primers for different loads, Fed 215 for 7mm SAUM, WLRM for 7mm WSM
, WLRM for 300 WSM
all with Magpro. So it must mean that different primers can be used with Magpro.
I have never experienced a hang fire with Magpro, but I do know that it seem to work best at or near Max loads.