If you’re shooting 6” high at 100 but grouping well, just zero your rifle at 100, probably around 2” high, and it will get you close to dead on at 200. The 2-3” high at 100 from a 25 yard zero is a guideline, not infallible. It will vary with trajectory or height of the crosshairs above bore centerline or a number of other factors. The 25 yard zero is just to get you on paper so you can zero at the preferred range. BTW, welcome to the fire!
Old 70
Not to get too far into the weeds, but you do not say whether your rifle is pre-enjoyed or new. Some barrels require "fouling in".
Also, your "rest" is not mentioned.
YMMV, but I find that "Magnums that shoot 3,100 FPS, plus, typically shoot 1" to 1.5" high at 100 yds. when zero'd at 200 yds.
If I'm correct the 300 WSM 150 Gr. Federal Fusion have a MV of +/- 3,300 FPS, and a decent Ballistic Coefficient.
As an aside there are innumerable references that calculate/provide trajectory info should you decide to shoot further than 200 yds.
Like others here, I get on paper @ 25 yds. Some rifles I only shoot 100 yds or less, others I set up to stretch out a bit further.
Next I zero, typically 1" to 1.5" high at 100, then zero at 200 yds. Once I'm satisfied with a group @ 200 yds, I then go back an shoot @ 100 yds and make note of the POI vs. POA. Some may disagree, but since you are shooting factory ammo, I'd say there is no reason to shoot five shot groups "all day long. Most Sako's I've dealt with will be "fouled in" with a dozen rounds or so.
Once the POI is to my satisfaction I like to either wait for the barrel to cool completely or even come back a second time and check the POI, first shot out of a cold barrel fired at the same distance as before. Once again, opinions vary, but I do not clean the barrel down to bare metal once I have the barrel fouled in and zero'd before I hunt.
You will know soon whether your Sako likes the federal fusion.
If you are planning on using your rifle to hunt rather than to see how small of groups you can punch on paper, I would not get too anal about achieving sub-inch groups @ 100. If your intended target has an 8" kill zone a 2 MOA shooter will do all you need @ 200 yds.
When you know ya' know, and ya' know you know, confidence replaces fear. Hard to beat OJT.
Believe it or not 100 yds. makes a difference, so as Kingston says "get out there and practice"
ya!
GWB
