??? ME,,,
but it all depends on how thick your barrel wall is,,if you have a really thin barrel
by the time we bore out,, theres nothing left of your barrel,,
and to do full length inserts is hard, as you end up with a taper,,
next shorter inserts are better,,you can run your paint tighter as theres less insert for it to break in,, a campayne cork travels over 300 fps,,but its barrel if you like is only the length of the cork.. why.. its a tight fit,,
but you cant run tight for long or the shell on the ball breaks..
send me your barrel and i will tell you if it can be bored out,,