a know a guy who has a custom gun done and he has a 300 rum imp that shoots 240gr match kings at 3200fps (that's with a 34 inch barrel and seating the bullets out further). he shot some 180gr bullets once just for fun (the bc is to low to shoot far with them. they drop to fast "way" out there) and he was around 3600-3700fps with them. it all depends what kind of gun your shooting.