Justasec here - how accurate does it need to be, anyway? If 2" is fine, then I'm sure it's do-able. H4895 is the usual reduced-load medicine.
Also - in a lot of cases, the 7mm Mag isn't putting anywhere near the advertised MV out in the first place. Depending on your rifle, it may not be that huge of a gap between 7 mag and 7-08 MV's in the first place and therefore shouldn't be hard to load down a bit