OCW Analysis - Am I reading this right??

buyobuyo

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Apr 14, 2010
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I shot a couple of OCW tests today with my new AR, and I was hoping that someone could confirm what I'm reading from the targets (or tell me I'm out of my mind).

Both tests used LC85 brass, WSR primers, and 77SMK bullets loaded to mag length. Powders were Varget and H4895.

Varget:
varget-1024.png


H4895:
h4895-1024.png


If I'm reading the targets right, it looks like the OCW range for both tests is 22.9 - 23.3 grains. I have larger pictures if anyone wants to see them. Both tests were shot at 100yds with iron sights from prone with sling support. I started with a clean rifle and cleaned between tests.

Thanks, Jeremy
 

buyobuyo

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Apr 14, 2010
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Re: OCW Analysis - Am I reading this right??

Hmm... Just looks at the targets again.

Varget may actually be 23.4 - 23.8 grains, and H4895 is 22.9 - 23.3 grains.
 

wirehand

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Jul 12, 2008
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Re: OCW Analysis - Am I reading this right??

Yea, larger pics will help.

Also if you shoot from a farther distance the disparity in POA and POI becomes more pronounced.
 

Outsydlooknin75

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DulUth Jawja
Re: OCW Analysis - Am I reading this right??

In all honesty I dont think that you can really tell much from the test because you said you were just slug up .... how much shooter induced error is there?

Whenever I do test I make sure that the rifle is as stable as possible using a rest of some sort up front and a rear bag so that way I am inducing as little error as possible.
 

buyobuyo

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Apr 14, 2010
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Re: OCW Analysis - Am I reading this right??

I have a LeadSled that I prefer to use when doing load development, but an AR doesn't fit in it nicely. The mag is the main problem.

Maybe I'll load up the tests again and re-shoot it from the LeadSled with the mag removed.
 

MitchAlsup

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Re: OCW Analysis - Am I reading this right??

In my opinion, the varget OCW is near 23.6 while the H4895 is near 23.5.

When I say near, I mean that at this point you have found a window of OCW-ness, while you have not identified either the center of the window, nor have you found the width of the window.
 

High Binder

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Re: OCW Analysis - Am I reading this right??

Once you think you have found your OCW go out and shoot a range of loads close to that one just so you can confirm your first shooting session's results.
 

mdmp5

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  • May 7, 2009
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    Re: OCW Analysis - Am I reading this right??

    I have had a real bitch of a time finding OCW for my AR. I had an entire page of 10 targets with the same general POI on each target, which could be either construed as a very wide range of effective charges or as inconclusive.
     

    Outsydlooknin75

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    DulUth Jawja
    Re: OCW Analysis - Am I reading this right??

    I would use the led sled with a 20 round mag ..... I think if you try to single load it will give different readings .....

    Id load a mag, chamber the first round and just shoot it but not at your target, that way you dont have the dreaded "first round flier" from a gas gun that some people run into.
     

    buyobuyo

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    Apr 14, 2010
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    Re: OCW Analysis - Am I reading this right??

    Thanks for all the suggestions/tips so far. I think I'll load up the Varget test again and see what I can come up with for targets to re-shoot it at 200yds.