I zeroed a scope on my old 8x60S Brno21 yesterday with these loads:
1. 200 grs Sako Hammerhead, 53 grs Vihtavuori N140, 2670 fps,
2. 250 grs Woodleigh, 49 grs Vihtavuori N150, 2390 fps,
The loads were developed and chronographed with iron sights, no signs of excessive pressure.

The first load was very accurate, grouping under an inch at 100 m, I zeroed it about 3" high. This would make the woodleighs hit on point of aim but 2,5" to the left. Group 1".

With iron sights at 50 m both loads were an inch apart dead on, an inch over the point of aim.

I made a compromise and zeroed the scope a little to the left, so I can use both loads.

But what is the scientific or main reason the point of impact differs sideways? Or is it an individual thing between rifles? Is it the twist, the movement of the barrel, the thickness of the jacket or all of these?
The holes on the target are fine, there is no stabilazation problem with the long woodleigh.

Please keep it simple, I�m no technician.

Boha

Have you tried experimenting with your bullet seating? This can have a major effect on the point of impact of your hand loaded ammunition.

No, I haven�t. But I�ll try it. The OAL of the loads are not the same, but then the Sako is semi pointed (80,9 mm)and the Woodleigh is round nose (82,3mm).

Boha

I have rifles that well put all bullets in the same hole others that will not. As long as you don't shoot at long range over 300 yards the way you sighted in should not hurt you. Way out there you well not be on.

My question is more of the academic sort. I do not need to fire my 8x60s on anything farther than 150 yds at the most. There are other more suitable rifles in my safe.

Boha

Boha - Is it the twist, the movement of the barrel, the thickness of the jacket or all of these?

Yes it is the twist, the movement of the barrel , the recoil and more.

Kimmo

The harmonics of your barrel changed when you switched bullets. I`ve seen same wgt bullets from different makers have different POIs but normaly not real drastic. The wgts your shooting don`t suprise me that they won`t shoot to the same spot. I`m not saying you won`t be able to get them to shoot to the same spot but, it will take a bit of experimenting.