OCW method, at its purest, has absolutely nothing to do with group size, and absolutely nothing to do with POI truth to POA. All you're trying to do is identify a window of powder charges which produce the least vertical dispersion due to variance in actual powder throw weight. In other words, all you're doing is looking at the variation from one group to another for vertical position relative to the POA.

Cut your target in half and put the bottom half beside the top so your POA's are all in line - that's the way an OCW target should be done, otherwise, it's difficult to interpret the results when the shots aren't strung above the same horizon.

After doing so, what you should be looking for is vertical displacement from one groups center to the next - meaning when you look at each group compared to its neighbors, are they all centered together, or are your groups riding a wave? When I did OCW (purely), I drew a line below the targets and measured up from the line to be able to track that "wave motion".

As Dan instructs, If you have a group that's two shots together then one spread away like :. you can't say the two shots are the group. I don't take the time to draw triangles and find the Centroid, I just pick approximately the center of the largest spread, and spike that as my actual average POI. You'll see below where the yellow line I drew passes through the groups - about in the middle of all 3, NOT distracted by the close together impacts.

So this is what you get:



At the left, between 1 and 4, there's a lot of noise, then at the right, 8 takes a pretty big jump up again. However, between 5 and 7 is very stable (with a respectable nod towards the left side 4).

IF YOU SUBSCRIBE TO THE OCW THEORY - then based on this target you should load between 43.7 and 44.0grn, closer to 44.0, since it's basically flat between 5 and 6, raising slightly towards 7, and falling slightly toward 4.

I'd probably load up another set in that range and shoot 5 shot groups.

In theory then, if you tune up the seating depth, you'll be able to tighten up those groups at that powder charge.

At least that's the theory...