284stak
Well-Known Member
For you 7MM shooters:
I have an 7MM-330 Dakota, built off a Rem 700 action with a 27 inch Shilen Barrel in a 1:9 twist, with an IOR scope and McMillan stock. This gun shoots 0.25 - 0.5 MOA consistently with 140 grain accubonds at 3400 fps, and does not seem to be finicky with seating depth, but I get best results at 0.015 off the lands. I have wanted to try a bullet with a higher BC for long-range windage issues, so have tried the 160 grain accubonds and the 168 Berger VLD's. Neither one will shoot nearly as well as the 140 AB's --- the 160's are in the 0.5 - 0.75 MOA's, while the Bergers are all over - sometimes shooting 3-4 MOA groups. I have tried the Bergers at the lands to 0.025 off the lands with no obvious improvement, and velocity adjustment from 3000 to 3200 fps. I have had poor results with the Lost River J36 160's as well.
Questions:
1. Do others have issues with the Bergers with this twist rate in 7MM?
2. Are their other high BC bullets I should try - ie Sierra MatchKings?
3. If I replace this barrel in the future - should I try a 1:8 twist?
Thanks for any input.
I have an 7MM-330 Dakota, built off a Rem 700 action with a 27 inch Shilen Barrel in a 1:9 twist, with an IOR scope and McMillan stock. This gun shoots 0.25 - 0.5 MOA consistently with 140 grain accubonds at 3400 fps, and does not seem to be finicky with seating depth, but I get best results at 0.015 off the lands. I have wanted to try a bullet with a higher BC for long-range windage issues, so have tried the 160 grain accubonds and the 168 Berger VLD's. Neither one will shoot nearly as well as the 140 AB's --- the 160's are in the 0.5 - 0.75 MOA's, while the Bergers are all over - sometimes shooting 3-4 MOA groups. I have tried the Bergers at the lands to 0.025 off the lands with no obvious improvement, and velocity adjustment from 3000 to 3200 fps. I have had poor results with the Lost River J36 160's as well.
Questions:
1. Do others have issues with the Bergers with this twist rate in 7MM?
2. Are their other high BC bullets I should try - ie Sierra MatchKings?
3. If I replace this barrel in the future - should I try a 1:8 twist?
Thanks for any input.