I've found 3300fps very doable in most every 7 I've loaded for. Nosler's powder charges will give you 200-300fps less than they show with the same charge with all the 140/7mag loads I've chronoed. Thier velocities can be reached but you must tilt the powder can. I've found 70grs of R22 will give me 3310fps with Accubonds in my 26" tube. I only got to about 3200fps with R19, IMR4831and Magprobefore I saw high pressure. I think 19 istoofast for 140's in the 7. Of course you need tobeginat the bookstart chargesand work up slowly as all guns are different.
Brett