06-24-2020, 12:38 PM
Last year, I bought a Howa mini-action rifle, with the 20" heavy barrel, in 6.5 Grendel. I have noticed a few things about it. First: I needed almost a hundred rounds, cleaning frequently, to break in the hammer-forged rifling. Second: my factory rounds are running slower than the published velocity. Hornady 123 grain Black is advertised with a muzzle velocity of 2,580 fps. My chronograph showed: 2,455 average, SD: 17. Hornady 123 grain SST is also advertised with a muzzle velocity of 2,588. But I get 2,479 fps average, SD:9.5. The accuracy was poor when I shot these because I used them for break-in. They ran 2 MOA. After shooting about 80 cheap handloads, the rifle shot much better. So far, these are the four most successful handloads, each delivering 0.5 to 0.6 MOA at 100 yards: 123 grain Lapua Scenar and 27.1 grains of Hodgdon Benchmark for 2,470 fps mv. 123 Lapua Scenar (and Hornady ELD) with 29.0 grains of Power Pro Varmint for 2,490 fps (varies with temperature, slower when cold). 123 grain Lapua Scenar and Hornady ELD with 28.2 grains of compressed Hodgdon Varget for 2,420 fps, and 130 grain Nosler Accubond with 29.0 grains of Power Pro Varmint for an unconfirmed 2,420 fps. I will continue testing once I receive my new chronograph (last one fell over in the wind and broke).