Congrats to your new rifle ! I think you know that I have same caliber custom Husqvarna m246. It has little thicker barrel but one another thing which makes it weight to appr. 4,5 kg is heavy wood in stock. My rifles balance is allmost ideal, maybe you need to add some more weight to your buttstock.
I recomment that you would buy somewhere one good quality dense wood piece and make a modern straight comb stock to yours rifle. It gives weight and stock model helps to make the shooting more comfortable.
With my Husse I can shoot 5-6 RWS factory loads with 19g TUG without any big issue. Of course, Pachmayr´s Decelator recoil pad helps too...;-)