I have this .308 rifle I just cannot figure what's going on even if my life depended on it, looking for stuff I may have overlooked if you guys wish to participate.
This is my 4th .308, and the only one to shoot Federal 175s GMM bad, and the slowest barrel I have ever owned. This 26'' gives the same velocities as my 24''.
I keep a box or two of GMMs in my safe for load dev diagnostic, all my 3 other rifles just loved GMM and the low node (42.7gn Varget + 175SMK), this one just hates the low node.
Interestingly enough, barrel is slow, but I can get to higher loads than any other rifle owned before, without the slightest pressure sign, and beating velocity of all the others.
Never had a .308 shoot 175 SMKs over 2800fps without the slightest pressure sign, and this one pulls it off!
As with all my others that went well, I set the trigger as light as I can go, use a Harris bipod, and definitely use and focus on fundamentals while in load dev mode.
After 2 bad sessions, I double checked the following...
Took rail off and re-installed, put some new loctite and torqued accordingly, old install was not loose.
Took rifle out of stock, and checked MDT bedding for abnormal use or marks, everything was clean, even 70 rounds later no paint used off the action where it hits the bedding. Re-installed in stock with appropriate torque.
Re-installed rings, ARC-M10 rings we're still very solid at 55 in/lbs nothing had moved.
Looked inside the muzzle brake for signs of copper markings, none at all very clean.
This is my sweet spot so far during the load dev, with results.
200M, 5 shot groups. Labradar showed single digit ES and under 5 SD. Labradar is downstairs but I'll post avg fps as I remember them, may be off a few FPS.
Flyers we're at random, they could well be at the start/middle/end of string.
Barrel was allowed 12-15 minutes between each group to cool off, which I have never done before!
44.5gn Varget : 4 shots we're sub 1/2 moa, 1 shot was 2 1/2'' apart (2790fps)
44.8gn Varget : 4 shots we're sub 1/4 moa, 1 shot was 1 3/4'' apart (2805fps)
45.1gn Varget : 3 shots we're sub 1/2 moa, 2 other shots we're touching each other 2 1/4'' away from the main grouping (2820fps)
This is my 4th .308, and the only one to shoot Federal 175s GMM bad, and the slowest barrel I have ever owned. This 26'' gives the same velocities as my 24''.
I keep a box or two of GMMs in my safe for load dev diagnostic, all my 3 other rifles just loved GMM and the low node (42.7gn Varget + 175SMK), this one just hates the low node.
Interestingly enough, barrel is slow, but I can get to higher loads than any other rifle owned before, without the slightest pressure sign, and beating velocity of all the others.
Never had a .308 shoot 175 SMKs over 2800fps without the slightest pressure sign, and this one pulls it off!
As with all my others that went well, I set the trigger as light as I can go, use a Harris bipod, and definitely use and focus on fundamentals while in load dev mode.
After 2 bad sessions, I double checked the following...
Took rail off and re-installed, put some new loctite and torqued accordingly, old install was not loose.
Took rifle out of stock, and checked MDT bedding for abnormal use or marks, everything was clean, even 70 rounds later no paint used off the action where it hits the bedding. Re-installed in stock with appropriate torque.
Re-installed rings, ARC-M10 rings we're still very solid at 55 in/lbs nothing had moved.
Looked inside the muzzle brake for signs of copper markings, none at all very clean.
This is my sweet spot so far during the load dev, with results.
200M, 5 shot groups. Labradar showed single digit ES and under 5 SD. Labradar is downstairs but I'll post avg fps as I remember them, may be off a few FPS.
Flyers we're at random, they could well be at the start/middle/end of string.
Barrel was allowed 12-15 minutes between each group to cool off, which I have never done before!
44.5gn Varget : 4 shots we're sub 1/2 moa, 1 shot was 2 1/2'' apart (2790fps)
44.8gn Varget : 4 shots we're sub 1/4 moa, 1 shot was 1 3/4'' apart (2805fps)
45.1gn Varget : 3 shots we're sub 1/2 moa, 2 other shots we're touching each other 2 1/4'' away from the main grouping (2820fps)