I have just bought a Sako 75 Finnlight from one of our SD members and am very pleased with it.
It shoots Norma 100 grain factory loads very well and with clean cases, however I have an issue with my home loads.
For my Sako 75 Hunter (20 inch barrel) I worked up a load of 44.5 grains of N160 under a Speer 85 grain SPBT in full-length resized Federal cases. It shot just under 3100 fps.
The Finnlight needs the bullet set 27 thou longer to be 20 thou from the lands. The person I bought it from has advised me of the loads that he used so I am not in the dark.
I have found that shooting the home loads from full length resized cases in causing blackening on most of the case. I have tried loading some Norma cases that have been fire formed in the Finnlight and neck sized only. This has reduced the blackening very much.
Strangely it will shoot the loads set for my original rifle with good velocity (3045 fps) but lots of blackening. What doesn't make sense to me at present is that the factory loads are shot leaving clean cases, yet the neck sized fire formed ones are a considerable improvement on the full length resized home loads.
What are your thoughts on this ?