I just bought a 7mm rem mag with a 9.5 twist. I have been trying to figure out what powder to buy and it seems most use H1000 or retumbo. I was looking thru a reloading book and noticed that IMR 4064 comes up in quite a few columns/bullet weights. I was excited to see this because I have six lbs for my .243. Has anyone used this in a 7mm or is there a reason I shouldn't? Thanks. Also will Berger 168 gr be ok with that twist?