Due to the fact that I have the opportunity to try almost any shape of lead projectile up to 20mm in length within a few minutes, I have tried a lot of them, but primarily we try to produce universal slugs that work equally well both in the FX slug barrel and in what I think are the most normal airgun barrels that have been used for several decades, i.e. the classic grooved barrel with a pitch of 1:17.7 (the best example is the Lothar Walther airgun barrel).
In our M24 airguns, I have no problem shooting with the same LW barrel JSB pellets, as well as our slugs. In addition, with the .25 caliber, you can find a suitable power setting so that I can shoot pellets and slugs without changing the muzzle velocity.
But personally, as I already wrote, I only use slugs, because the difference is simply negligible.
I see the more important of choosing a suitable slug diameter for a given barrel, because apart from the FX barrel, all other barrels on the market have a "normal" sufficient twist.
