A lot depends on how hot you are willing to load.
To take Keith's load as an example to compare, I load 70 gr of RL22 with a 150 BT and 150 NPT for a velocity of about 3125. I know I can go higher,likely up to just under 3200 but what for?
Accuracy is excellent to 600 yards, and the load will knock the socks off any NA big game.
No 270 is going to safely give you 3100-3200 fps with a 150 gr bullet. Many will not do that well with a 130 from a 22" barrel.
here's my own velocity thresholds with the 7 RM, YMMV:
140-3200-3250 (yes I have killed game running them clear over 3300).
150- 3150
160- 3000-3100.(Mostly they settle in at 3050 or so).
175- 2900-2950
None of this is anemic
When i see these velocities I STOP. You won't find a 270 or 280 that will duplicate them. If you argue with me I will ignore you.
Good luck I wish you all the best.
I have seen the 7 Rem Mags that give 3200 fps with 160's,and 3400 fps with 140. Those velocities are the province of bigger jugged 7mm's like the Mashburn and Dakota, LRM, etc. I would be very uncomfortable seeing those velocities from a 7 RM. You may not blow yourself up but you are teetering on the edge IMHO. YMMV.
