OCW which one?

[Splat]

I have three loads that shot great. I guess 42.8 and 43.6 had about the same POI
Shooting 178 AMAX with Varget seated at 2.80"
Which one?

Sorry for the sideways pic... And I wrote the wrong gr bullet on the sheet. It is 178gr AMAX.
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[lash]

42.6

Actually, for full disclosure, I'm totally new to load development and have just this week been spending time reading up on Dan Newberry's OCW method. So take this for what you feel it's worth.

Anyway, what I see is that 42.4 and 42.8 are almost exactly the same POI, meaning to me that that is a sweet spot. I'd next load up 42.2-43.0 in 0.2 increments and see where they are most consistent in velocity. Then choose the middle load, as that one lets small variables ( like temp changes, slight brass volume variations, etc.) happen without impacting your POI.

Again, I'm a total newb to load development, but I'm an engineer and the logic is applicable, based upon the method as developed. I'm sure that there will be some very experienced guys along soon to comment.

 

[Splat]

This the first time I've done a OCW. I've always done ladder testing.

 

[shoot4fun]

You are into a node at 43.6 and need to further test around that charge. I would do 43.4, 43.6, 43.8 and 44 grains. Discount minimal horizontal dispersion and watch out for scatter nodes. Also, please tell me you didn't shoot 49 grains of Varget with 178 AMax as your target seems to indicate. Your seating depth looks pretty good.

 

[ArmyJerry]

43.6 is very close to my 308 Lapua 175 smk load,, its 43.5 of varget

 

[Twoboxer]

Your 42.8 and 43.6 don't have similar POIs, they are your best groups. Need to look at groups immediately around them for direction.

Your 42.4 and 42.8 have similar POIs, but it shifts and opens up by 43.2. I'm thinking 42.6-42.7 for that node.

Assuming you shot 44.0 and 44.4 at the diamond tip/topofbar, I'm thinking 43.7 for that node.

IOW, I'd explore closely around 42.8 (probably favoring lower) and 43.6 (probably favoring higher).

 

[Splat]

You are into a node at 43.6 and need to further test around that charge. I would do 43.4, 43.6, 43.8 and 44 grains. Discount minimal horizontal dispersion and watch out for scatter nodes. Also, please tell me you didn't shoot 49 grains of Varget with 178 AMax as your target seems to indicate. Your seating depth looks pretty good.

That would be 44.0 gr and my bad handwriting.


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[Darkside-Six]

Your 42.8 and 43.6 don't have similar POIs, they are your best groups. Need to look at groups immediately around them for direction.

Your 42.4 and 42.8 have similar POIs, but it shifts and opens up by 43.2. I'm thinking 42.6-42.7 for that node.

Assuming you shot 44.0 and 44.4 at the diamond tip/topofbar, I'm thinking 43.7 for that node.

IOW, I'd explore closely around 42.8 (probably favoring lower) and 43.6 (probably favoring higher).

^^^this!


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[trailrider121]

If it were me, I would work between 42.4-43.0 grs. You seem to have a good ocw node, and would retest in .2 grs increments. You target says maybe a high node around 44.4- 44.6, but I would check and watch for pressure signs. What brass are you using?

 

[Splat]

If it were me, I would work between 42.4-43.0 grs. You seem to have a good ocw node, and would retest in .2 grs increments. You target says maybe a high node around 44.4- 44.6, but I would check and watch for pressure signs. What brass are you using?

I'm using Lapua brass. This was done with twice fired & neck sized only with Lee Collet die. I will probably bump the shoulder back before firing this brass again. I have a couple hundred new Lapua that I need to fire form.

 

[trailrider121]

Splat, If your using Lapua brass I would say your OCW would around the 42.8grs area.

 

[parsky1]

What primer and barrel length?

 

[Splat]

What primer and barrel length?

Fed 210M with 20" LW AIAT barrel.


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