I have two 8mm Mausers one is a semi custom the other is a full custom made by a very taleneted rifle smith.
I could blindfold anyone, hand them ten different rifles, and when the full custom 8mm was in their hands they would be able to pick it out from all the others.
This gun is so sweet it makes everything else feel like your holding a 2x4 in your hands.
The 8mm can be handloaded to give 30-06 performance.
8MM Mauser, keep practicing you have one fine rifle that will make you an excellent deer rifle.
I tip my hat to your Grandad, I would say he's a fine gentleman that cares about his Grandson and did an excellent job in building you a great rifle.