Ahhh gentlemen perhaps you can be of assistance
although it's not a 9.3x74R like yours I have a Husqvarna Model 46 bolt action in 9.3x57 Mauser and have tried to paper patch some 0.358" cast bullets with little sucess :-[ Now the moulds I have are both Lyman being:-
35875 which is a flat nosed plain base bullet which is a claimed 200 grains
35897 which is a gas checked tapered nose bullet of a claimed 232 grains
Now I cast them of pure lead, perhaps that was the mistake? Part of the problem will be that the groove diameter of my rifle is 0.370" although the land diameter appears to be 0.3545". The bullets from the 35897 mould drop at 0.358" in pure lead and weigh 240 grains. However the bullets from the 35875 mould drop at 210 grains weight and 0.362" diameter.
I just oiled one of each of the bullets and pushed them through the bore from the muzzle end which is how I got the land diameter. It would appear that the muzzle end of the barel may be 0.355" as measuring it with a digital caliper gets this reading. These bullets have hardened somewhat as I cast them about 6 years ago now. At the moment none of the casting equipment is set up as I have no room for it at the moment. Later this year I will have space in a shed in which to cast once again.
This is my first venture into casting and the moulds were brought at an Arms Fair at Bisley Camp and both sets now have handles on them but did not have when I brought them. They do not appear to have been used or if so used very little.
Any help would be most appreciated.