....The real question is not if gain twist works, or not, but if it is possible to create a middle-ground twist rate that serves equally both long conical-type bullets and also for patched round balls.
Nothing but the best of luck with the project. I'd consider asking your chosen barrel maker what their favorite barrel configuration is and what specific projectile is matched to it. I'd think middling barrels are already plentiful. I believe if you discuss it with the barrel maker, purely for twist rate, the bullet will only be affected by the final twist of the gain. It may matter if the bullet encounters different affects cause by the gain, and how skillfully the barrel making was executed. There are modern gain twist barrel makers, one more so, that have quite a record of accuracy accomplishment under competition conditions with correctly matched lead bullets. Only thought, again best of luck.
