180 Berger Hybrid wind drift

[Canhunter35]

I've been shooting a 1:8twist 7 rem mag with the 180 hybrids. It's a 28" tube and my mv is 3052fps. I've corrected my curve to 1630yds, so I know my mv and bc is pretty close.
Lately I've been taking 1-3 shots each day from 800-1300 yds, but my wind calls seem low, I'm basing it off my wind chart from applied ballistics.
I've taken my 6.5, and shooting side by side I'm basically holding the same wind with a slower and lower bc bullet.
So I'm wondering what other guys experience in wind deflection with using this bullet at long range.


One of my theories is with the 8twist barrel I'm over spinning the bullet causing it to remain nose up when it should track down to the angle of attack. And this is causing the increased wind deflection. Just a theory, what's your thoughts?

 

[lancetkenyon]

Are you always off to the right? Are you calculating spin drift into your equation along with wind drift?
Are you zeroed true center?

 

[Canhunter35]

Are you always off to the right? Are you calculating spin drift into your equation along with wind drift?
Are you zeroed true center?

Yep, I'm calculating spin drift, and my zero is pretty close. This is a cold bore shot on the orange

I've experienced increased wind drift from 3:00 and 9:00 winds.
I've performed a tall target test with this scope and level, and it was level.
The spin drift seems less than it should be. Yesterday, I had a 12mph wind from 3:30. I had to hold .4mil more than I expected and never dialed spin drift in. I held my 6.5cm with nearly the same wind hold and engaged target

 

[lancetkenyon]

What about your drops? Do they match predicted drops from you ballistic calculator?
Are you using G1 .674 or G7 .349"?
Maybe adjust BC if the drops are not matching either.
I don't think a 1:8" is overspinning a 180 Hyb. Mine is a 1:8.5", and I have shot other 1:8" 7RMs using 180s. Never had anything but great luck with them. From 2900 to 3250 (in a 28 Nosler w. 1:8").

 

[Canhunter35]

My drops r matching, I'm using .345g7
I'm really happy with how it's shooting, I made a 3" group at 922yds.
If I didn't have another rifle to confirm I'd think it was just bad wind calls.
It's not the end of the world, if this pattern continues I'll adjust my wind charts
Yeah I wouldn't thing a 1:8 would be overspinning, but not sure why I'm having the results I am

 

[Hand Skills]

C'mon guys, how can you deny the CM is actually magic now that we finally have evidence?

Seriously though, tagging in. That's an interesting phenomenon @Canhunter35

 

[lancetkenyon]

C'mon guys, how can you deny the CM is actually magic now that we finally have evidence?

Seriously though, tagging in. That's an interesting phenomenon @Canhunter35

I almost mentioned that 6.5CM phenomenon too....

 

[Canhunter35]

Lol yeah yeah.
I'd bring my 308, but then we'd be talking about the 7mm magic.
Maybe that's what I'll do though, you can't be off on ur wind calls with a 308.
Just shot at 1055 with a 5mph/6:30 wind call, dialed my spin in, held .25mil left and center punched the plate
That matched the wind chart but it was a mild tail wind

 

[Canhunter35]

So I made a load with 197smk at 2920fps and using .4g7
Was shooting it back to back with the 180hybrid.
Using jbm ballistic calculator with same inputs and confirmed hits at 1315yds, and a 8mph 125degree wind, jbm gave wind holds of 1.49 mil for the 197 and 1.69mil for the 180.
The 1.5 mil really was spot on.
I was using 2mils of wind hold for the 180s
It's not scientific but confirms my suspicion at least to myself lol.

If anyone is interested in using the 197 in a rem mag I pressured out with h1000, but retumbo gave excellent accuracy at .5gr below pressure signs