This is my latest problem, due to a lack of primer choice/brands,i have recently purchased a 1000 Fed Gold medal Match MAGNUM primers. Im loading 308 and 243 with Vhit 140 and 160 respectively.I have been using Fed 210s for years but have finally ran out. A couple of friends say that if i reduce the Powder load a little that it will be fine/safe.HOW MUCH IS A LITTLE.???? Any starting points, is there a rule of thumb?. None of my loads are really hot,308 is about 2500fps, 243 is about 3400fps.This is worked of load data as i have no chrony.