Seating Depth Testing: Round Robin or All At Once?

[trailrider121]

I've tried both in round robin and all 3-rounds at once in testing groups. I prefer to shoot all 3 rounds in one sitting, trying not to change position, or cheek weld if possible. Trying to keep everything the same, so I get less deviation in testing. FWIT, that's my method.

 

[Winny94]

If the op's test was shot at 100 yds as I suspect then I doubt the wind is the culprit in the horizontal spread at 0.010". The vertical is about the same at 0.010" & 0.090". I would expect that a good load could be developed at either one of these seating depths. There is no information about the rifle or the use of the round, but if feeding from a magazine is an issue then 0.090" may be the better choice. If there are no magazine restrictions then it is up to the shooter. In this scenario I would probably test both seating depths to see how they develop, but I would be surprised if both were not more than adequate.

Wind was 5 mph @ 100 yards shooting a 7mm SS - I dont believe wind was a factor. I am shooting from a mag, so the .090" definitely takes any OAL considerations out of the equation, but Im not opposed to loading in the .010 range either if it shows potential as I have a short throat so I can load right up to the lands and still fit the mag. I dont want to get into the lands as pulling a bullet during a hunt would be a major issue. I am going to shoot it again and see what happens.

 

[Ringostar]

For your hunting rifle, I would stay with the longer jump. Work again within the .090 range. A little higher and lower. Then work on your powder at the seating depth that you choose. The 7 SS is close to the SAUM. You should be able to take SAUM data and reduce slightly to start.