Off topic a little bit but with the thin skirts, I wonder if they ‘open up’ any if spun too fast?Dave
How do you divide them (RPM and Twist).Certainly, the same barrel (same twist) launching a pellet at 500fps spins a pellet half as fast as one launching it at 1000fps.Equally certain the RPM decays much slower than forward velocity, so as range increases the forward-velocity-to-RPM ratio is actually faster than barrel twist would predict for the velocity.
one interesting example about twist rate choice is by Daisy...My old 1985 953 has the L.W. barrel with it's 17.7 twist... as do the 753 and 853... the Modern 953 with the Daisy barrel has a 15 twist...These of course are 10 meter rifles that tend to on average be about 475 fps or so with 7.4g wad cutters... so 475x(12/15)x60 = 22,800 rpm out of the 15 twist rifle... and 475(12/17.7)x60 = 19,322 rpm out of the 17.7 twist that is a difference of about 3500 rpm...but truth is even out at 30 yards there does not seem to be a noticeable difference... sort of want to use the 1:15 Daisy barrel I have as a Stormrider barrel... along with a L.W. and Crosman just to compare them at closer to 950 fps...with light to heavy pellets and slugs... at 950 fps the difference in rpm doubles... to near 7000 rpm...
Ribbonstone,I would be more than happy to design a 3D printable custom air stripper for your smoothbore, gratis, to see if reducing the blast following the pellet in front of the muzzle improves pellet stability and reduces group size over range.