Engineering101
Well-Known Member
Got some data today that you may be interested in if you are planning on using the Berger 180 grain HVLD in your new 28 Nosler.
The rifle: Sako L61R action in original Sako stock (with lug epoxy bedded), Krieger 1 in 8 twist bull sporter at 26 inches, Vias style brake, VX 6 Leupold 3 to 18X.
All were 3 shot groups using US869 fired at 200 yards. The following data is the grains of US869/muzzle velocity/group size.
88.0 gr/2,985 fps/2.281"
89.0 gr/3,046 fps/0.797"
90.0 gr/3,077 fps/1.797"
91.0 gr/3,225 fps/2.281"
92.0 gr/3,173 fps/1.625"
93.0 gr/3,214 fps/2.875"
This is not a heavy rifle so I was pleased to see several groups under 2 inches. The one at 0.797 inches may even be repeatable. It landed on the target in a place none of the other groups went which indicates some positive (null) barrel harmonics to me. At least that is what I'm hoping. I will be loading more of that load. I will also try a few more loads on the high end as I never did get any pressure signs. Primers were starting to flatten out at 93.0 grains but I'm guessing that 94.0 grains will be useable and that 95.0 grains will probably start getting sticky. I'll update this after I've tested those and another batch of 90.0 grains.
The rifle: Sako L61R action in original Sako stock (with lug epoxy bedded), Krieger 1 in 8 twist bull sporter at 26 inches, Vias style brake, VX 6 Leupold 3 to 18X.
All were 3 shot groups using US869 fired at 200 yards. The following data is the grains of US869/muzzle velocity/group size.
88.0 gr/2,985 fps/2.281"
89.0 gr/3,046 fps/0.797"
90.0 gr/3,077 fps/1.797"
91.0 gr/3,225 fps/2.281"
92.0 gr/3,173 fps/1.625"
93.0 gr/3,214 fps/2.875"
This is not a heavy rifle so I was pleased to see several groups under 2 inches. The one at 0.797 inches may even be repeatable. It landed on the target in a place none of the other groups went which indicates some positive (null) barrel harmonics to me. At least that is what I'm hoping. I will be loading more of that load. I will also try a few more loads on the high end as I never did get any pressure signs. Primers were starting to flatten out at 93.0 grains but I'm guessing that 94.0 grains will be useable and that 95.0 grains will probably start getting sticky. I'll update this after I've tested those and another batch of 90.0 grains.
