I've broken in my Howa 1500 .308 HB 26" with about 500rds. of 147gr. and 180gr. practice ammo. I've only been shooting at 100yds. for about 2 months and now I'm shooting into one big hole by the time I get 20rds. down range, with a couple of flares. I will be moving on to the 200yd. range soon and I think I need to start thinking about correct bullet weight for my rifling. My Howa is a 1 in 10 and I understand that around 180gr. is where I need to be for the best match for my rifling. This is what I think I've read so far, but I'm still learning long range shooting. After 200yds. the science gets more exact the further out you shoot. But now I'm thinking about buying 500rds. of Federal premium match 175gr. Sierra Matchking HPBT. I don't want to buy a bulk amount of ammo and regret it. So, any thoughts?