The best load for my 24" 11.25 twist 308 is 41 grains RL-15 and the 190 SMK at 2600 FPS and it averages less than 1" at 300 yards (3 shot)The best I can do w/175 SMK is 2" at 300 yards with MV of 2554 FPS. The 190 makes sense to me
Curious Question for those shooting 190 gr anything out of a 1:12 twist. How'd you get them to stabilize? Before I put my new 11:27 twist Rock barrel on my .308 rifle, I couldn't get the pervious 1:12 twist barrel to stabilized my 175 gr bullets.
I can't imagine getting .5 accuracy with a 1:12, but more power to you if you're getting it.
Before I tried the 190s in my 1-12 barrel, I emailed the techs at Sierra asking about how they would stabilize. They went to the trouble to load up a batch at around 2200 fps and shot them in their testing facility. Their results were a .5" groups at 200 yards. After hearing that, I loaded some up and they shoot fine.
It sounds almost like you had 1 rifling slightly longer or shorter. A 12 twist isnt the best for the 190, but it will stabilize it. According to some new twist calcs, the 190 at 2600 is at 1.5 stability factor with an 11.25 twist. 12 I think is between there and 1.0 which is still acceptable. I have put these calcs to the test with hair splitting accuracy. 175's can be very accurate from a 12 twist, even 13 twists. If you still have that barrel, I would have it recrowned by a good smith.