Re: .243 blown primers
I would seariously consider using a different powder or a different bullet. I have no experience with that powder brand. However, I have had a similar experience using Hodgdon's loading data and a 22-250 switching to a 60 grain pill. I used a medium load to start with since I had maxed out the powder with no problem and a 55 grain bullet. First shot blew my primer out, stretched the case. Idiot me didn't realize that the case had blown out yet so I had shot an additional 2 rounds with the same result. I didn't realize until the 3rd shot actually blew the ejector plug back in the bolt face of my Savage rifle.
moril is that the charts arent always right for every rifle/bullet/powder combo.
and yes, i did pull my head out of my rear since then. ;)
I used to re-load but now I "hand-load".
-- Well, at least I try