Help with grouping issue

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by AFRIFLEMAN, Apr 16, 2014.



    Apr 16, 2014
    I've heard about people shooting their 375 H&H out to 1000yrds + so I decided I'd play with mine a bit and see how well it worked. I've had this rifle several years (shooting a variety of hunting bullets) and have never had a problem with it. Now that I've set it up for long range I'm having an issue. It'll group fine 2/3 of the time but it randomly throw a bullet out of the group usually 6-10 MOA. When it first happened I thought it could be me, but after playing around with it I realized it wasn't. Here's the setup.

    Weatherby Mark V 375 H&H 1and 10 twist
    Vortex Viper PST 4-14X50
    Seirra 350gr Match bullets
    72 grains of H4350
    2400 FPS at the muzzle
    Winchester brass
    Fed 215 primers

    The rifle isn't a great shooter around 1" - 1 1/2" MOA out to 600yrds (as far as I've tested it). After I realized the problem wasn't me I thought it was the scope. So I tested it. Due to the issue it won't complete a scope (ladder) test without throwing a bullet out. But the scope always returns to zero. I've set up targets all the way to 600 yards and the scope will dial correctly to each distance I've tested. At every distance I shoot it will put a few rounds on target and then randomly throw one. Sometimes it's the 1st or 2nd round sometimes it's the 3rd or 4th. I don't shoot more than 4 rounds without letting the barrel cool completely. It will even put a bullet on target after it throws one out (without scope adjustment). Which makes me think it's not the scope. I've checked to ensure the barrel is free floated and there isn't any odd pressure on the barrel. I always shoot off an ATLAS bipod and a rear sand bag. The rifle was glass bedded by me (recently) and it has a factory muzzle break. I've checked the end of the barrel and cannot see anything on the crown that might cause the issue. I know the rifle twist isn't ideal for this bullet but I know of other people who have had success with the same rifle twist. I'm thinking it's the barrel but have never heard of a rifle having this type issue. Does anyone have any ideas? Thanks