I just received my Ruger M77 Hawkeye RSI 275 Rigby. The 7x57 caliber is new to me but had been diligent in my research to establish some basic guidelines of where to start and what to expect from this cartridge. To begin with I am at a bit of a disadvantage as my rifle only has an 18 1/2" barrel. I had pre loaded a bunch of ammunition to sight in and test when the rifle arrived and yesterday I spent the day at the range with these results at 110 yds.
Remington Brass Win. L/R Primer 120 gr. Hornady SP Varget OAL 3.025
After sighting the scope I shot 7 strings of 5 starting at 38 gr. up to 45 gr. of Varget. I found this powder to work very well with the lighter bullets in my 6.5x55 and results were more than satisfying with the 7x57. The best group was 0.62" with 43 gr Varget and an average velocity of 2672. That will do nicely for 120 gr.
My next experimenting will be 150 and 160 gr. bullets with IMR4350 . I will post results when I get a chance to get out again.
