I'm using various calculators and equations to determine ideal twist rate for a projectile fired in a sabot. Some call for groove diameter (.50 or thereabouts) and some call for projectile diameter (.43). Using one or the other number gives a very different result. I wonder if anyone knows for sure which figure to use for sabots?
I have a PA Pellet with 1 in 48 twist and am trying to find a good sabot load. A gunsmith I trust said to try a 200 grain XTP at .44-40 velocity level (1000-1250). As it happens this seems to stabilize perfectly according to the numbers using groove diameter (.50), but the same equation says to push it at 2000+ for stability in a 1 in 48 assuming .43 diameter.
I imagine the actual diameter of the bore has an effect on all this just like the length of projectile, etc, but my brain isn't quite equipped to grasp the nuance.
I have a PA Pellet with 1 in 48 twist and am trying to find a good sabot load. A gunsmith I trust said to try a 200 grain XTP at .44-40 velocity level (1000-1250). As it happens this seems to stabilize perfectly according to the numbers using groove diameter (.50), but the same equation says to push it at 2000+ for stability in a 1 in 48 assuming .43 diameter.
I imagine the actual diameter of the bore has an effect on all this just like the length of projectile, etc, but my brain isn't quite equipped to grasp the nuance.