I'm so far impressed with my longbow using the .685 barrel back. I haven't used the .690 much. I have a .687 back coming to me in the mail from Sakworldpaintball.com
When I used the .690 barrel I had a couple broken paintballs in my hopper. While I was shooting the balls started going EVERYWHERE, but I was still able to get the last guy out (I dumped a whole lot of paint on him).
As for the .685 barrel, I know I have broken a ball in there before--maybe it was b/c the bore was too small or the paint was dimpled/bad. For just a few shots (like 5) the balls would kinda shoot squirrely but relatively straight. Then after that it kept shooting perfect
My question for you now Mann is...would you recommend me picking up a 12" or 16" barrel tip for longbow?
If I could get my hands on a year 2000 scepter kit--that'd be awesome.
I'm very excited to try the .687 back--i think it will be the one that is most used.