Milan, thank you for the kind words - I sure wish you had shot some more - I'm starvin'' here!
James, thank you too!
Though Henry Childs,HBC) and others have chastised me for equating twist/RPM,centrifugal forces) with bullet failure, a 7.5" twist rate SCARES me - the IDEAL twist for the 95 is 1:10",Sg = 1.5 @ Std. conditions). Assuming they pass muster, even the new 121 Gr. FB will require only a 1:8" twist rate - none of that radical, precision robbing "faster" is better stuff.
On his web page, Dan Lilja,Lilja Rifle Barrels: < riflebarrels.com > )has some very informative articles regarding this topic . . . At risk of being an idiot, in general, a FB bullet of equal or, slightly greater weight, compared to a BT, is shorter, thus requires less RPM for equal or greater Sg. And CG offset+RPM equals larger groups . . well, that's the theory!
I just received some preliminary results from HBC's initial results with the new BIB 108 and 121 Gr. bullets - via his 7" twist barrel, the 121 show promise, while the 108s are going to disintegrate - this IS as I expected. In our local testing, though limited to just a few barrels, in "cool" weather, we have been unable to destroy either the 95s or, 108s via 9" twist barrels - this at any realistic pressure/velocity obtainable from a 6mm Re. and/or 6x250 Ack. Imp., with several powders,H-4350; N-540; Varget; RL-15). We have one 8" twist barrel which "vaporizes" the 95 and 108s as soon as we hit pressure/MV of 3100 FPS. There are so many variables involved here,possibly, including rifling profile, land/groove diameters, etc.
By the way, via our 8" twist barrels,6x250 Ack. Imp.), the 95s do not survive at pressure/Mvs in excess of 3100 FPS: call me ignorant - I do not recommend 8" twist barrels for the 95s. I am surprised by the excellent results people are experiencing/reporting via 8" twist 6BR/Dasher/BRX cases; I must confess, I did not expect such good results via this model. Further, I stand by my belief that when combined with a 10" twist, the 95 will prove even better; a 9" twist provides a good compromise - it is perfect for the 108s!
R.G.
