[jon penrith]

What are Omer thinking of with the xxv? If your gonna have an open muzzle for better sighting why use rubbers that pull in line instead of circulars??
Interestingly Fabrizio of Totem sub guns did some tests & found that rubbers which are split/screw in still caused the spear to wobble as the spaer passes out of the trigger mech & over the guide in the middle before passing out of the muzzle.With circular bands & a rail the rubbers keep the spear on the rail & this doesnt happen.
As for the rail slowing the spear down,Rob Allen says that the spear travells on a film of water which acts as a lubricant.Either way i cant see it has a massive effect.