Finally went beyond 1000 yards

[BrentM]

A real calculation shows the same bullet weight at the same speed blah blah at 1000 yards

140gr
3000 fps
.600 vs .500 bc G1
10 mph at 90 degress
5000 ft
59 temp


600 bc = 49.5" or 4.7 MOA
500 bc = 62.7" or 6 MOA

 

[WildRose]

Question for you experienced guys out there. Is wind drift affected by B.C. in that the lower the B.C. the faster the bullet slows down and the longer it is in flight being affected by the wind?

For example, could drift be calculated by the mass of the bullet and it's time of flight, or is there something to the shape of the bullet as well?

Case in point, if you had two bullets of the same shape / weight, but one (somehow) had a lower B.C. would they have the same amount of drift at the same time in flight. Even though the lesser B.C. bullet would not have carried as far due to velocity loss?

Thanks (if you followed all of that),

The short answer is yes. The higher BC bullet as a general rule is going to see less wind effect all else being equal.

Think for just a minute here. If you have two balloons that are exactly the same shape and size, but one filled with air and the other filled with water which will be more affected by the breeze if you hold them both in your hands outside? Of course the one filled with air will.

All else being equal it takes more energy to affect the flight of the heavier mass.

 

[BrentM]

I just realized I forgot the word QUICK behind real. Anyway, that was from the Hornady ballistic calculator. I do know that other brand non vld type bullets have the same basic weight with different bc numbers. Thought the difference was a bit surprising actually.

 

[BrentM]

Took it to 1333 today while out hunting wolves. Shot a rock that proved to be harder to find impacts on then I thought. It was 40f, 25.75 abp, -6 slope. Showed 36.6 moa and wind was 4 with a 4 moa left hold. One of two shots was visible. Dead center and about 10 inches low. Going out again tomorrow if weather cooperates and will try it again.

 

[BrentM]

Went to 1482 and knew this was going to be tough due to wind and my ability to read it. It felt mostly the blowing left to right at 7 but it was not consistent with gusts and lows. Anyway, the computer said to go 5.9 left, with 43.6 up. Ami nor I could spot the impacts at all from the distance. Got to the rock and found 2 of the 3 for sure. Both impacts were left, verticle, and 15" apart, about 2moa, and 1 to 1.5 moa low. I think the 3rd was way left since I held a few more MOA left thinking I read the wind wrong.

OK, so to make things more interesting when I got back to the truck, we on the 4 wheeler, I decided to re-check the zero. It was shooting low and left. 1.7 inches left, and 1 inch low.

I have to not tried to do any calculations but that might account for some of misses, any thoughts?

 

[WildRose]

Went to 1482 and knew this was going to be tough due to wind and my ability to read it. It felt mostly the blowing left to right at 7 but it was not consistent with gusts and lows. Anyway, the computer said to go 5.9 left, with 43.6 up. Ami nor I could spot the impacts at all from the distance. Got to the rock and found 2 of the 3 for sure. Both impacts were left, verticle, and 15" apart, about 2moa, and 1 to 1.5 moa low. I think the 3rd was way left since I held a few more MOA left thinking I read the wind wrong.

OK, so to make things more interesting when I got back to the truck, we on the 4 wheeler, I decided to re-check the zero. It was shooting low and left. 1.7 inches left, and 1 inch low.

I have to not tried to do any calculations but that might account for some of misses, any thoughts?

Still, not to shabby at that range!

Sounds to me like perhaps you need to do a box test to ensure your scope's elevation and windage click values are correct and consistent.

What scope is it you are using?

 

[BrentM]

Night force.

I had an incident a few weeks ago and it knocked the scope off 6 inches at 100. It seems to be ok but I worry.

 

[Broz]

Fine tune that parallax while zeroing. And I don't mean to a crisp picture.

Jeff

 

[BrentM]

This is what bothers me. First round is the one dead on. Then the group. I used the group to re-zero and they all were tight. This is 200 yards. Those are 1 x 1 squares

 

[BrentM]

Picture

 

[WildRose]

This is what bothers me. First round is the one dead on. Then the group. I used the group to re-zero and they all were tight. This is 200 yards. Those are 1 x 1 squares

You kind of lost me here.

Are you saying your first shot is dead on, but then POI shifts when you shoot a group, and you then adjust to bring the group to POI-POA?

 

[BrentM]

Stupid picture. The 3 shot group is actually low left. Just like my impacts at 1482. So on the parallax how do recommend I set it. It might not be correct.

 

[BrentM]

Well that seems to be the case here. I need to test this again and see if happens consistently. Thoughts?

 

[WildRose]

Well that seems to be the case here. I need to test this again and see if happens consistently. Thoughts?

Your picture shows about 2" Low and 1.5" right.

If you are consistently getting this kind of shift then either something is loose inside your scope, your scope mounts are loose, or you have an impingement problem somewhere or your action screws are not properly torqued.