When I designed that bullet, the Kolbe calculator said the optimum twist rate was 20-22".... However, a flat base bullet of the same design (without the boattail) would use a 26-28" twist as optimum.... The Kolbe calculator usually overestimates the loss of stability of my Bob's Boattails, they are almost always stable in a bit slower twist than predicted, and quite often stable in a twist rate that Kolbe recommends for a flat-based version, particularly if the boattail is not too extreme, which is the case for that design (the boattail was shortened from an earlier drawing to lighten the bullet).... Bottom line is, if you have a 26" twist TJ's barrel, I would try it, I think it may be fine....Bob
You know after sending this I realized I could just test in my 29" 1:26 barrel and push it as hard as I can to try and get the velocity up. Just enough shots to see if it wants to group or patterns like a shotgun. If my local compressed gas company gets restocked on nitrogen this week I'll do some testing. The 1:16 twist is scary fast to me in .357, I don't think I will take that leap of faith without anyone sharing first hand experience pushing 1000fps MV out to 100 yards....
Quote from: mackeral5 on March 13, 2021, 11:11:59 PMYou know after sending this I realized I could just test in my 29" 1:26 barrel and push it as hard as I can to try and get the velocity up. Just enough shots to see if it wants to group or patterns like a shotgun. If my local compressed gas company gets restocked on nitrogen this week I'll do some testing. The 1:16 twist is scary fast to me in .357, I don't think I will take that leap of faith without anyone sharing first hand experience pushing 1000fps MV out to 100 yards....I was just researching this 'faster twist rate in a .357' because of those new Russian barrels being offered in a 390 twist rate by alfa-precision.net. They are just over 15.3" twist rate, and I am using the 1:26" twist with decent results at over 200 yards. I use the NSA 142 grain HP-BT currently, and exclusively, because cast bullets were not MOA accurate out at long range.With the 390 twist barrel would you think by getting the FPS up to 960 or more that it would stabilize better? What about if only pushed in the lower 900fps range? And, does a faster twist barrel require a longer bullet?
I see NO sign of tumbling.... I would definitely go with the 26" twist barrel....Bob