In the 7.62X39 using IMR-4227 and keeping pressure to 45K CUP or lower, I suggest the following Max Loads:
115 gr - 19.0 grs - ~ 2150 fps
130 gr - 19.0 grs - ~ 2100 fps
155 gr - 18.0 grs - ~ 1900 fps
165 gr - 18.0 grs - ~ 1800 fps
There's no reason you couldn't use heavier bullets and with less powder.