Not a gun smith or bullet designer, I know that on a Sammi chamber like mine the 170 berger is pushed back into the case past the shoulder junction therefore taking up some of the case capacity. As I stated in prior post, maybe a good Smith or bullet designer could tell us how much freebore a regular sammi 270 would need to get the bullet moved forward to take advantage of using more powder. Maybe instead of 2900 fps we could get to 2950 or 3000.. No matter it is shooting well enough as is.... but, with freebore I believe it would have even more long range potential.. 800 yards with a 170 EOL dropped a 6 point bull in its tracks... Bullet performed flawless.... Is this the be all, end all set up?? No it is just a great option to use a well designed 270 case. You just get a new barrel with a 1:8 twist.. Freebore to get long bullets out of the neck junction.. Simple. The amount of freebore I don't know.