RowdyDan,
First off the Swede has a .480" rim diameter. The 6.5x47 Lapua has a .473" diameter. The 6.5 Grendel has a .44". The Grendel will be too small to fit the bolt face of your Swede's action. You'd have to either obtain a new bolt with a .44" bolt face or have 'smith work it so; if that's a possibility.
The 6.5x47 will provide better ballistics, great Lapua brass, small primer pocket to hold up to nuclear pressures.
I'm sure a good 'smith could work any issues that might have to do with putting a short round cartridge into a long action; such as blocking the mag.
Alan
