Yep, always clean between shots for best accuracy...The condition of the barrel affects each shot so if it's clean each time, you are consistant...

As far as a "tight" barrel, that's controlled by using a different sabot, like the crushed rib or the MMP-24...You can even go to a .430 diameter bullet and a crushed rib...

It's not the bullet or sabots fault the barrel was bored a little too small...Kinda like buying the right size shoe, change sabots...