09-21-2019, 03:49 PM
I really doubt that you're going to see much - if any - benefit from going with the tighter 1-7.5tw with bullets no heavier than 123grs. I've used 1-8.5tw bbls on several of my custom rifles chambered for larger rounds such as 6.5-08 Improved, 6.5x55, 6.5x55AI, and 6.5x284, which were all used out to 1000-1400yds, with 140gr bullets from various makers, including VLD & Hybrids from Berger, and never had an accuracy issue. Just remember, the faster you spin a bullet, the more critical the quality of said bullet becomes. That's the main reason point blank BR shooters using the 6PPC go with 1-14tw bbls - granted, they're shooting custom made 68gr bullets at 100-300yds, and there's no need for a tighter twist. But even with best-quality custom bullets, they stay away from over-spinning them to minimize the effects of even barely measurable variations in jacket thickness.