Can shooting into the wind lift your bullet?

[Bigcat_hunter]

I'm working on a drop chart for a new 300 RUM shooting 210 bergers at 2750ish fps. It was shooting 4" high at 800 yards and shooting over the 1000 yard target. So I adjusted the velocity calculation to lower impact and now it is right on at 800 yards but a good foot high at 1000 yards.

There is usually a wind coming directly at you at the range so you are shooting into the wind. Can this head wind be lifting my bullets at the last couple hundred yards of the range?

 

[Broz]

Sounds like mirage or possibly scope turret calibration (tracking) to me. I would shoot with out mirage first. Also make sure you are properly adjusting out all parallax. And of course check zero too.

 

[Tumbleweed]

If you are shooting over flat ground then I would say no, the wind could not cause lift, at least not to the extent you're seeing. When shooting directly into the wind the air pressure should be equal all around your bullet which would not cause a shift in any direction other than where the bullet was already headed. If you have some serious hilly terrain and such that you are shooting across, then yes you could certainly be seeing lift. What you're experiencing could be a combination of incorrect data input into your ballistics program or even a scope that is not tracking correctly.

 

[dragman]

Yes the wind can change your bullet impact sometimes up sometimes down just depends on at what point the wind is hitting it.

BUT your talking almost 7 MOA in change. like Broz said you have another problem somewhere.

 

[Bigcat_hunter]

It's got to be the scope. I have a Vortex PST that wouldn't hold zero. Sent it back twice. Finally holds zero but now it looks like it won't track. I already have 400 rounds down the tube trying to figure it out. Anyone want to buy a Vortex? I'll give you a hell of a deal LOL.

 

[4xforfun]

"2750ish" sounds kind of low for a rum with 210's. Are you sure about the MV? This could be your problem......a "garbage in, garbage out" thing.

 

[Broz]

It's got to be the scope. I have a Vortex PST that wouldn't hold zero. Sent it back twice. Finally holds zero but now it looks like it won't track. I already have 400 rounds down the tube trying to figure it out. Anyone want to buy a Vortex? I'll give you a hell of a deal LOL.

What rail base and rings??

 

[Broz]

"2750ish" sounds kind of low for a rum with 210's. Are you sure about the MV? This could be your problem......a "garbage in, garbage out" thing.

That is a good analysis. What powder charge? What program? what chronograph?

Is your program turret correction set at 1.0?

Have you tested the tracking in any way?

What BC are you entering? G1 or G7?

Was there any visible mirage that day?

Did you adjust out parallax? If so explain how?

Rings out of square will transfer stress into the scope tube and will often result in a tracking issue.

If I had sent a scope in twice and thought it was bad again I would test every aspect before jumping to conclusions.

There are tons of PTS's out there that are doing just fine. This does not mean you don't have a bad scope but I would prove it bad first.

Jeff

PS if you want to sell it silly cheap PM me. I have had good luck with them.

 

[Bigcat_hunter]

What rail base and rings??

I have a 20 moa base, cant remember which brand and nightforce low 30 mm rings.

 

[Bigcat_hunter]

I am using jbm ballstic program. The only tracking I have tested have been at the range shooting. I am using G7. Yes a little mirage but not bad. I adjusted parallax by turning parallax until the reticle did not move on target while moving my head up and down.

edit: forgot a couple of things. I have a powder charge of 95 grains of 50 BMG. Using a shooting chrony. It's a cheap chronograph but has worked well for me over the years. What would cause a huge jump in height from 8000 yards to 1000? By the way this scope was messed up. It wouldn't hold zero and after I sent it back the second time they said they forgot to tighten a lock ring or something. It is holding zero now.

That is a good analysis. What powder charge? What program? what chronograph?

Is your program turret correction set at 1.0?

Have you tested the tracking in any way?

What BC are you entering? G1 or G7?

Was there any visible mirage that day?

Did you adjust out parallax? If so explain how?

Rings out of square will transfer stress into the scope tube and will often result in a tracking issue.

If I had sent a scope in twice and thought it was bad again I would test every aspect before jumping to conclusions.

There are tons of PTS's out there that are doing just fine. This does not mean you don't have a bad scope but I would prove it bad first.

Jeff

PS if you want to sell it silly cheap PM me. I have had good luck with them.

 

[Bigcat_hunter]

"2750ish" sounds kind of low for a rum with 210's. Are you sure about the MV? This could be your problem......a "garbage in, garbage out" thing.

Im shooting a mild load with h50bmg. I gave up on getting H1000 and just settled on whats available. Its slow but extremely accurate.

 

[Broz]

If it is an EGW aluminum rail I would pull it and see if the mount holes are egged out. See it many times.

Also get a set of scope center points and see if the rings are in alignment and not tweeking the scope tube.

So to test tracking of the scope have you shot a group at 100 then cranked in 20 moa and shoot another group using the same point of aim as the first? Then verify that the second group is 20.94 " above the first one?

What G7 BC do you have entered in the program now?

 

[Bigcat_hunter]

If it is an EGW aluminum rail I would pull it and see if the mount holes are egged out. See it many times.

Also get a set of scope center points and see if the rings are in alignment and not tweeking the scope tube.

So to test tracking of the scope have you shot a group at 100 then cranked in 20 moa and shoot another group using the same point of aim as the first? Then verify that the second group is 20.94 " above the first one?

What G7 BC do you have entered in the program now?

I will try that tracking test at the range. I guess that would tell me right away if it's tracking correctly.

I am using the G7 BC of .323

 

[Broz]

I will try that tracking test at the range. I guess that would tell me right away if it's tracking correctly.

I am using the G7 BC of .323

Yes, good place to start and also you can recheck zero and load accuracy at the same time.

If it proves to not track look real close for any mount problems that could be inducing stress in the scope tube.

I would probably test at 10 moa and 20 moa. Just take 1.047 x the dialed in moa and that is how far the point of impact should move, in inches, at exactly 100 yards.

Jeff