has anyone tried IMR 4166 in the 308 or 7MM-08

Vines:

I've done some preliminary work with 4166 in both these calibres, plus in the 22-250, 6mm Rem., and .257 Roberts. In all 5, velocities have been good, and standard deviations low, but in the 3 small bores the accuracy hasn't been near that obtained with IMR4064, Varget, or RL15, other components remaining the same.

In the 7-08 (an old Browning A-bolt) I've only tested it with the 139 gr. Hornady PSP. Results were promising. Peak accuracy was at about a couple of grains less than the Hodgdon max., and accuracy and velocity were comparable to my previously established hunting load with H4350. I think further testing with other bullets lies in the future.

In the 308 (a late 80s Rem. 700 BDL), I've only tested it with the 168 gr. Hornady A-max. Peak accuracy in the initial testing with WINCHESTER match brass was with the starting load, about 4 gr. below the Hodgdon max., at about 2380 fps. A second test with that accurate load compared the light WINCHESTER brass with heavier R-P brass and even heavier PMC brass. In R-P brass the load was 40 fps faster, and in PMC brass 90 fps faster. However, I got the same results as in the initial test - as velocity went up, accuracy deteriorated. I can live with the relatively low velocity, if the accuracy remains consistent, as this rifle is only used for 100 yd. Hunter Benchrest matches. However, I'll probably load up a test batch with 4166 and either Hornady or Sierra 155 gr. match bullets this coming winter to see how it performs with the lighter bullet.

Hope this helps.

Cheers, Al

thanks for that Al, your data is encouraging. I'm awaiting delivery of a 7-08 custom build from my gun smith and have a can of 4166 waiting.