After PaddyD's comment in a post a few days ago about his success with IMR4166 powder in his .308, I finally got around to loading some IMR4166 for my Savage 10 FP .308.
the 10 FP is an old rifle (2009 vintage) with a relatively new fluted target barrel that I had Savage install after the original barrel started to show some effects of throat erosion on accuracy after more than 6500 rounds.

With 5 round groups at 100 yards in temperatures from 35 to 43 degrees and winds from 5 to 8 mph:
1 shot 11 groups with 4 closely matched loads of IMR4166 using 168 Tipped Match King (TMK) bullets seated out between 2.850 and 2.868 O.A.L. at velocities around 2620 fps.
Average of all 11 groups was 0.410. This was the second best Powder-Bullet combination average that I have ever achieved with this rifle.
The average of the previous 168 grain loads with 168 TMKs was 0.453 for 83 groups with 4 different powders.

The best powder bullet combination was 0.399 with 155 TMKs and IMR4064 powder. It is still in first place.
The best powder bullet combination average with 168 TMKs with IMR4064 powder is 0.487.
The best previous powder bullet combination average with 168 TMKs was with N140 powder is 0.433.

That gives IMR4166 powder first place among the 168 powder bullet combinations.
IMR4166 powder will shoot pretty well in an old .308.