Recently, I wrote about having to use a new bullet for my .303 British rifles since the Sierra MatchKings were not to be found. I loaded a series of rounds with powder charges of IMR-4895 from 38.0 grains to 40.0 grains in 1/2 grain increments. I was hoping to come up with a common loading that I could use in both my SMLE No. 1, MkIII and my No. 4, MkI.
As it worked out, I was successful! 38.5 grains was the most accurate in both rifles. The best prone slung group being this!
Myopicvisionary 