OCW, next step?

[58blackflag]

I loaded up some 178 amaxs with Varget in lapua brass and got the results in the pic below. The two five shot groups on the sides are both 175 FGMM to be a sort of baseline.
For the OCW powder charges going top to bottom were:
First-3 41.0, 41.9, 42.8 sighters/foulers

Then, 43.1>44.1>44.6>45.0>45.4

I started to get slight ejector marks from 45.0 and 45.4.

44.6 seems to look pretty good so, next should I load say 5 rounds each of 44.6+/- 0.2 grains and shoot them round robin format? Better that or just load 15 at 44.6 and adjust seating depth 10 thousandths each way? I don't have much time to do a lot of development...I need to have 250 rounds made for a weekend class coming up soon so I need to just get something set soon.

 

[waveslayer]

I would personally load 5 like you said and do round robin at least 200-300 yards away after the OCW to find your true node. It has worked great for me. I would do 44.4, 44.5, 44.6, 44.7, and 44.8if yyou are short on time.

 

[Aimsmall55]

Just shoot the damn thing at what you think is the best load. No point in waiting bullets on shit that isn't going to tell you anything other than I've gotta load more up .... I've never done an ocw. If I find a good load that shoots great at 200 yards. That's what I stick with.

 

[shoot4fun]

Just shoot the damn thing at what you think is the best load. No point in waiting bullets on shit that isn't going to tell you anything other than I've gotta load more up .... I've never done an ocw. If I find a good load that shoots great at 200 yards. That's what I stick with.

I respectfully disagree. The process, when done exactly as described by Dan, puts you in your tuned node with less loading, less powder, less bullets and less trips to the range than using any SWAG method out there.
To the OP, google Newberry OCW, read carefully and follow exactly. Too many people are using it with success for it to be a waste.

 

[Pinecone]

WAY to large of steps. You can be skipping right over accuracy nodes.

The OCW method uses 0.7 - 1.0% steps. That is .3 - .4 grain steps in the 40 grain range.

3 rounds per step are all you need. And make sure you shoot round robin

I developed an Excel template to do all the charge step calculations. You can find it here - http://www.snipershide.com/shooting/snipers-hide-reloading/193057-ocw-excel-template.html

 

[58blackflag]

I went back today and tested in 0.1 grain increments from 44.4 to 44.8. 44.5 looks like the ticket, the group was 0.6" edge to edge.
I shot all test groups round robin.
Next I plan to load 20 rounds or so to shoot over a chrono to check the speed and consistency. Also shoot a few out at 500-600 yards to check at distance.

 

[flashhole]

How far away was your target for the OCW test? If you are not at least 200 yards out it is hard to tell anything from the resluts, 300 yards is better. What you want to look for is the smallest vertical dispersion. Don't get hung up on windage. Your initial increments of .9 grains is too large. You can ignore the low end charges and focus on acquiring your top end load range.

 

[Pinecone]

OCW is shot at 100 yards. And it works at 100 yards, IF you follow the procedure.

Proper powder charge increments, shot round robin, adequate cooling between shots, etc.

 

[rduckwor]

44.5 looks like the ticket, the group was 0.6" edge to edge.

Wow! There's a shocker. Seems that 44.5 +/_ a few tenth of a grain of Varget is the mainstay for any 308 in the 175 class bullet. Glad you found your load and I hope it works well for you all the way out.