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Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: September/30/2017 at 18:13
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On my 6.5 creed i chrono 2565 from 41.2 grains of h4350.

On my 300 wsm 2975 from 63 grains rl17.

Went to range today and shot them from 100 yards out to 800 yards. I used my ballistic calc to get data. Well it was way off at every distance. So i record the actual data and come home. I just couldnt figure out how things were so far off. Checked and checked my settings and i think everything is correct. So i start changing the velocity. When i get the creed to 2800 it is near exact all the way to 800 yards. No distance off by more than .25 moa.

I do the same with the 300 wsm and get it to 3200 and everything is right on out to 800 yards.

I just dont see how it is possible i could be getting those velocities. I womdered scopes, but two scopes off exactly the same. Two rifles off almost exactly the same.

What am i missing here?
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: September/30/2017 at 18:15
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Bullets 143 eldx
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Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: September/30/2017 at 18:26
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I'd say a chronograph error…  looks like you are approximately the same value off… 235 fps on the 6.5 Creedmoor, 225fps on the 300WSM.  
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: September/30/2017 at 18:28
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But 2800 fps from my 20” creed. I dont see how that is possible.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: September/30/2017 at 18:37
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Also i have ran data in two calculators and get same results
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: September/30/2017 at 18:38
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It is a mystery.  
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: September/30/2017 at 19:00
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I can't come up with a RECOMMENDED way you get to 2800 fps with a 20in barrel.  2635.  Doesn't say it can't be done.  
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: October/01/2017 at 16:44
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Tail Wind ?  Devil
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: October/01/2017 at 17:46
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There was really no wind that day.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: October/01/2017 at 18:02
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FM...
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: October/02/2017 at 15:36
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I wonder if its because of the BC of the bullets?? I am sure the ELD is up there. The ones I loaded in my 308 were LOOOOOOOOOOOONNNNNGGGGG!!! 

I have never shot a barnes. Wish I had a place I could shoot 800 yards, or better yet, a gun that would. 
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/05/2017 at 02:59
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What happens if you lowered the BC of the bullets you fired and kept the velocity the same? Doubt the chronograph is off if you were not getting pressure signs on the brass.  You could also check the scope by doing a tall target test at 100 yds to see that the bullet impact corresponded with the change in scope dope.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: December/05/2017 at 20:57
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my creed shot 2830 fps with 123 gr bullet out of a 21" tube with 44 grains of H4350. I loaded up until the primers seemed like they wanted to blow out, then i reduced the charge by 1/2 grain.
Your velocity seems to be just fine as far as i can guess. Note: just a guess.
What i think may be the culprit is your formula or calculation.
Namely, you may have something wrong about BC, temperature, atmos pressure, etc


Edited by anweis - December/05/2017 at 21:02
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