Ocw test help

jb41291

Bobby
Full Member
Minuteman
Jul 24, 2017
638
158
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Colorado springs, CO
Did my first ocw test today. Just need input from others who are more experienced and better read the results. Starting load was 39 and worked up by .4 grain increments. I did not gey any high pressure signs from my heavier charges. Any input would greatly help so i can plan my next step.

NOTE: 39.4 i shot another round as i felt i pulled one shot. 42.2 has a marked hole with a z for my first shot to get sighted in. That little guy, dont worry about that little guy.

Goals: Not dead set on a high velocity/powder charge. Mainly looking for a temp stable, consistent, and accurate load. So far i am thinking of looking between 41.4 to 42.2. Im thinking 41.8 might be the sweet spot for my setup.

Components are:
130 eldm bullets
Starline 6.5cm srp
Rl16 powder
Cci 450 primers

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Others here are better at this than me, but I would likely reshoot 39.9-42.5 at .1 gr. Increments 5 shot groups. You did not mention OAL as it relates to the distance of the ogive from the lands. I would load at 0.020” off the lands for this part and then once you settle on CW, load another batch at CW and adjust your OAL towards the lands in 0.005” increments.
 
Others here are better at this than me, but I would likely reshoot 39.9-42.5 at .1 gr. Increments 5 shot groups. You did not mention OAL as it relates to the distance of the ogive from the lands. I would load at 0.020” off the lands for this part and then once you settle on CW, load another batch at CW and adjust your OAL towards the lands in 0.005” increments.
I load my rounds .020 off the lands. I Need to confirm the the cbto length though.
 
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I would personally play around in that 40.6 to 41 node and also the 42.2 as they both are showing the least vertical spread. If you could get out past 300 yards that would help in your decision as well.
 
Shot 41.4 to 42.2 today. Mirage was kickiui ng my butt so i shot an extra round per load so 4 shots total. The poi all look pretty consistent. Any one think i should load 41.8 and just do a seating depth test next weekend?
 

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I like 42 as well. In your original target your rounds are impacting at the 12 o’clock position a step down and a step up from 42(41.8 and 42.2 respectively). You had a little more vertical stringing at 41.8 but that tightened up at 42 and 42.2. At 42 if you slightly undercharge or overcharge you should have nearly an identical POI. I would take the others advice and shoot this out at 3-400 yds on a day with low mirage and see how it shakes out. That will really help to highlight the optimal charge weight.
 
Finally got to do a ocw test for my tempest.

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Shot round robin with 5 rounds in each target. Well, attempted to. Targets 4, 5, and 6 are short one round each due to light primer strikes. From the looks of it either target 5 or 8 are my scatter nodes. Based on ocw test guidance of scatter nodes being 1.5% up or down from a ocw, if i go with target 5 my ocw would be either 41.7 gr for or 42.9 gr. If i go with target 8 as my scatter my ocw would be 42.6 gr or 43.8 gr.

Even considered 41.1 gr on target 1 to be the scatter node as its spread and pattern are unique from all the others. Going above it would bring me to 41.7 gr.

I am thinking of using 41.7 gr as my ocw. Let me know what you think or recommend. Still learning to read ocw results. Any feedback is appreciated. Thanks!