In theory, pellets can be shot accurately out of smooth bore.
having tested this exact thing in the past(two years ago) I found pellets shot from a smooth bore had far less accuracy then ones shot with even the slightest twist. Modern pcp guns are getting slower and slower on twist rates as compared to years past though as we are finding you do need twist but not nearly as much as once thought. The fx smooth twist is a great example of a smooth bore with just a slight twist at the very end. Very accurate with pellets and horrible with any solids.
I'm Shooting NSA, FX, and ASA slugs out of a .25 cal. 600mm STX barrel and and I wouldn't call the results horrible.
QuoteI'm Shooting NSA, FX, and ASA slugs out of a .25 cal. 600mm STX barrel and and I wouldn't call the results horrible.FYI, Travis was describing the original Smooth Twist in which only a portion near the muzzle is rifled.The Smooth Twist X (STX) is a different design in which the entire bore is rifled.While their twist rates on paper may be comparable, the former produced an actual rate much, much slower on account of the pellet already having reached near max velocity before hitting the rifling. It would therefore skid through the rifling and pick up only a small fraction of the twist rate...sufficient to stabilize a pellet but far too slight to stabilize slugs.