My OCW results question

[DarrellA]

The photo is of my results shooting 5 shot groups for 10 charge weights, increasing by 0.4 grains each step, starting at 37.5 grains and ending at 41.1 grains. I shot round-robin to try to minimize the effects of the barrel heating and my own technique - which seems to be to start poorly, get into grove and nail it and then get tired and/or sore and start losing focus and control. So it was one shot at #1, one shot and # 2, and on and on until all 10 targets had 5 shots each. I ran the bore snake through the barrel after every 10 shots. I worked through the bullet seating depth exercise in an earlier set of tests. And I'm going to probably play with that some more once I get the OCW narrowed down.

Varget powder
140 grain Berger VLD bullets
7mm-08 Weatherby Sporter, 24" barrel
100 yards

I'm thinking that the best groups are nos. 7, 8 & 9. IMO, the stray shot(s) to the right on # 8 has to be operator error, or a poorly constructed hand load. Does that seem reasonable?

The next step I'm considering is to decrease the intervals to 0.2 grains each and shoot the weights that include, and fall between, nos. 7 & 9. Does that make sense?

 

[18Echo]

Drop it to only 3 rounds for OCW and go up about .3 at a time, try it again.

 

[noylj]

#7 looks like the winner. Never ever ignore "flyers." Unless you called them, they are just as real as any other shot.
Personally, I would just repeat #7 and 0.2gn up and down. Shoot five groups at each charge weight to verify repeatability. One great group does not mean anything--believe it or not, it CAN be random.

 

[rduckwor]

The vertical on 7/8/9 look best to me. I concur with your plan.

As long as you had no pressure issues in that load range, I say get'erdone.

 

[Twoboxer]

In a word, yes your plan makes sense to me. Targets 7-8-9 look like they have potential, but they are 0.8gr apart and somewhere in there should be a scatter node. So that bothers me. So I might start below load #7 and end above load#9.

I also think targets 3-4 have potential as well. An OCW might be found at load 3.5 lol. Lower velocity, but might be useful depending on what you want to get from this load.