Re: OCW help...168 and 175 grain
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: groovinpickle</div><div class="ubbcode-body">By the OCW method, shouldn't you mark the center of each three shot group and compare <span style="font-style: italic">that</span> point among the targets? Otherwise I'm not sure how your method is any different from the old standby of shooting a bunch of groups and picking the one that looks the best.</div></div>
I believe the OCW website says you should pick the three groups that are closest in distance and placement from the center, it really doesn't have to do with group size.
From the OCW site...
14. Triangulate the groups. This means to connect all three shots in a triangular form, and determine the center of the group, and plot that point on the target. Measure this point's distance and direction from the bullseye, and record the information somewhere on the target. Do this for all of the targets. If you have a called flyer, you should discount that shot, or replace it in the group if you have an additional round loaded with that charge.
15. You will now look for the three groups which come the closest to hitting the same POI (point of impact) on the targets. The trend of the groups should be obvious, normally going from low and favoring one side, to high and favoring the other side. But along the progression, there should be a string of at least three groups that all hit the target in the same relative point.
16. After you have carefully measured group sizes and distances and directions from the bullseye, you will know which three groups come the closest to hitting the target in the same POI. You now choose the powder charge which represents the center of this string. For example, if 34.7, 35.0, and 35.3 grains all grouped about 1.5 inches high, and about 3/4 of an inch right of the bullseye, you would choose the 35.0 grain charge as your OCW (optimal charge weight). This charge will allow 34.7 and 35.3 grain charges to group right with it. This will be a very "pressure tolerant" or "resilient" load.
17. Remember, don't get "bowled over" by a tiny group which falls outside the OCW zone.