The 270 is SAAMI registered at 65,000 psi.
The most common bullet for the .270 is the 130 gr.
I have shot 9 mule deer between 400 and 500 yards with 50 gr IMR 4895 and 130 gr Nosler ballistic tip from a 22" ultra light Pac Nor barrel on a pre 64 M70 receiver in a Bordon Rimrock stock, with a Leupold 2x7 scope with Stoney Point elevation knob and 13" Harris swivel bipod. Loaded up with ammo, this weights 9 pounds.
This is 2875 fps = ~ 50 kpsi.
This is wimpy.
I don't know why you want to go even wimpier.
I need to be kind of wimpy to stay accurate in that light weight rifle.
If your rifle his heavier than my ultralight, you may want to go for 3,000 or 3,100 fps with 4350, a traditional loading.
But if you reallly DO WANT wimpy, 4895 down loads very well.