OCW test with PP 2000 MR .308 @ 200 yards.
- Thread starter Lausboob
- Start date
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I believe I would go with the 46.2. The method as I understand it is to narrow down a charge that has larger window of accuracy to either side of the given charge to allow for subtle changes in temperature etc that would otherwise swing accuracy greatly. at 46.2 you have such from what I can see. With all the charges hovering around MOA, if this were my rifle I would call it good. You may tighten that up even more if you have not yet tweaked in seating depths.
Of course, If I am off base in my understanding of OCW, then the above is useless.
Of course, If I am off base in my understanding of OCW, then the above is useless.
jasent
Well-Known Member
I would do an other ocw test with tenth grain increments from 46.0 to 46.7 you may hit you node a little better some where in there
I would not use any increment smaller than 1/2 grain. Too many shots from adjacent 1/10th grain groups will over lap each other. It even sometimes happens with 1/2 grain increments, especially if each load's accuracy ain't all that great. And many loads with a 3/10ths grain spread in charge weight will shoot no worse than 1/2 MOA at 600 yards; 1/3 MOA at 300 and 1/4 MOA at 200.
MontanaRifleman
Well-Known Member
No clear winners IMO. Not with 3 shot groups like that. I would repeat them all @ 300 yds on a no wind day.
What is your ES and SD? Need a chrono for that.
That is one of the flaws with OCW, short distance and not using a chrono does not tell you what it might do at longer ranges.
ES over 25 or so and your LR groups go to pot.
I would shoot from 46.0 to 47.2 in .3 gr increments over a chrono. Others may disagree but Oh, well.
Pick the best load and then reshoot for seating depth variation again over a chrono.
That is one of the flaws with OCW, short distance and not using a chrono does not tell you what it might do at longer ranges.
ES over 25 or so and your LR groups go to pot.
I would shoot from 46.0 to 47.2 in .3 gr increments over a chrono. Others may disagree but Oh, well.
Pick the best load and then reshoot for seating depth variation again over a chrono.
unvisable
Member
Measure each hole in each of the groups horizontally and vertically using the center dot as point 0,0 with positive up or right of center; negative being down or left of center .
Average each three horizontal measurements and each three vertical measurements to get the group center. That will yield as many ordered pairs as you have 3 shot groups.
Plot each point on a clean target and connect the points in sequence. you can see how the cwnter of the group is moving around.
Small movement between centers indicates stability of powder load. That is what you want with OCW.
Group size for OCW really doesn't mean much as long as all of the shots were "good" shots.
Picking a charge weight between two or among three is fine. After this you can do seating depth checks.
Average each three horizontal measurements and each three vertical measurements to get the group center. That will yield as many ordered pairs as you have 3 shot groups.
Plot each point on a clean target and connect the points in sequence. you can see how the cwnter of the group is moving around.
Small movement between centers indicates stability of powder load. That is what you want with OCW.
Group size for OCW really doesn't mean much as long as all of the shots were "good" shots.
Picking a charge weight between two or among three is fine. After this you can do seating depth checks.
