Need help with my UP'S ? Help!!

[Down Under Hunter]

Just starting to lack some confidence in my long range system and thought I'd tell you all whats going on.

Went out today and shot my DE 338 edge at my 1130 M steel gong.

Conditions were as follows.

RH 57 %

ALT 120 ft

BP 29.8

Temp 74f

I am using 2830 as my velocity on the NF exbal programme.

I had a 4 oclock wind that I was shooting for 5 mph.

The shot is a tough one accross multiple draws and gulleys for about half the distance, then for the last half rises on a bout a 15 degree incline to the target.

Exbal came back with 35 moa up. Knowing that in previous sessions I have been going high with almost everything I dialled 33 up. This went high. I ended up at between 30.5 and 31 moa up to consistantly hit the plate ?

I then went to my 1530 yard gong with the following conditions

alt 154 ft
bp 29.75
rh 70 %
temp 71 f

exbal gave me 50.5 up

I dialled 46 up to hit ?

Everyone on my six sessions so far except the very first day, my moa elevation adjustments have varied to exbal by a long way, and frankly I am getting worried that something in the equation is screwed ?

My windage is generally pretty good, but I cant seem to get close on elevation even at short ranges like 400 -500 yards, where I am still hitting high.

I know that the updraft factor will be at play to a degree, but is 4-5 moa out, factoring a following wind feasible ??

Could one of you plug the conditons into exbal for me and see anything I am missing.

I am fairly sure that these shots I'm taking accross this terrain would test the best shooter in the world, but I I sure wouldlike to be a little closer to what the PDA is giving me ??

I am shooting the 300 smk.

Any clues would be really appreciated

Cheers all

DUH

 

[Wild_Bill]

Exball

For the details you gave I got 34 moa for the first one and 57 for the seccond I will write it all down later and re enter it.

Cheers Bill

 

[Down Under Hunter]

Bill,

I cant understand why you would get such different results ?

There was a little mirage out there yesterday, but I am starting to feel I am missing something else ?

DUH

 

[MagMan]

DUH, I also ran your #'s and came up with 34.25 on the fist one and 49.25 on the second one.

Just a question but do you realize you listed the first shot in Meters and the second shot in Yards? This would get confusing to me. Perhaps this is why Bill's second # is wacky.

You've checked the BC and made sure that is right? For you to have the actual drop that you are using the BC would have to be .87 @ 1530 yds and even higher to make 31 MOA @ 1235 yds. I think we can both agree this is not the issue.


Have you checked your scope at 100 yds to make sure a MOA is in fact an actual MOA. I know you have a NSX but anything is possible. I like to use 20 MOA for checking purposes. I don't think it is this either.

If you are confident in what you are doing is right I'd use an adjustable BC and do more shooting. If you keep hitting what you are aiming at then leave it alone and just accept it. Although there should be an answer.

 

[Down Under Hunter]

DUH, I also ran your #'s and came up with 34.25 on the fist one and 49.25 on the second one.

Just a question but do you realize you listed the first shot in Meters and the second shot in Yards? This would get confusing to me. Perhaps this is why Bill's second # is wacky.

You've checked the BC and made sure that is right? For you to have the actual drop that you are using the BC would have to be .87 @ 1530 yds and even higher to make 31 MOA @ 1235 yds. I think we can both agree this is not the issue.


Have you checked your scope at 100 yds to make sure a MOA is in fact an actual MOA. I know you have a NSX but anything is possible. I like to use 20 MOA for checking purposes. I don't think it is this either.

If you are confident in what you are doing is right I'd use an adjustable BC and do more shooting. If you keep hitting what you are aiming at then leave it alone and just accept it. Although there should be an answer.

Magman,

Thanks for your thoughts.

I just get that feeling I'm missing something ?

I definitely entered the 2 distance as 1130 M and 1400 M. Sorry for any confusion.

I shot the same 1400 target last week and exbal gave 49.5 I ended up at 47.5

This week- exbal 50.5, I shot 46.5 up.

Should exbal be closer than this ?? Does it seem reasonable ?

maybe a combo of mirage and updraft.

can updraft account for a 4-5 moa difference though ?

I will need to check my 100 M zero and chrono the load to check things completely

DUH

 

[britz]

I was thinking about that one yesterday and playing around with jbm calc.com. Just a thought, but are you sure what the actual distance is from center scope to center bore- your shooting a Nighforce scope arn't you? Pretty high off the rifle to accomodate that big 50 mm bell. Also I'd second your thought of checking your hundred yard zero and velocity again.

Like I said, just a though cuz you are obviosly a much better shot than me if you can consistantly hit targets at 1530 yards

Good luck and keep us informed, Mark.

 

[Shawn Carlock]

DUH,

I ran the program 7 ways from Sunday. I could not find any combo pf factors that would put you off that far. It can't be shooting as fast as it would need to to achieve the lower drops. No amount of conditions changes (within reason) will do it. I checked all the sight adj specs no combos there either.
I can only think of a couple possible issues.
1. Check to see that your 100 yard zero is good.
2. Take a large piece of paper 4' tall, put a dot at the bottom confirm 100 yard zero. Then dial up 35 moa, shoot and measure the verticle travel. It should be 36.5". If this checks out the see the next.
3. In a cross wind over certain terrain features the wind will cause lifts. Even a 5 mph wind can cause lifts like you are seeing at those distances. The feature you are most likely lookinf for is a ridge or a draw below your line of sight running away from you toward the target. Hope this helps if it doesn't drop me an email.

 

[Jon A]

As has been mentioned, biggest things to check: Click value of scope, 100 yd zero and velocity.

However, before any of that answer this--how was the distance to the gongs measured? If a rangefinder gives you the range of the hillside or bush behind the gong, you dial accordingly, you'll shoot over the gong. At that those ranges the bullet is coming down steeply, so when you get a large vertical error even a small error in range can easily explain it.

 

[Down Under Hunter]

As has been mentioned, biggest things to check: Click value of scope, 100 yd zero and velocity.

However, before any of that answer this--how was the distance to the gongs measured? If a rangefinder gives you the range of the hillside or bush behind the gong, you dial accordingly, you'll shoot over the gong. At that those ranges the bullet is coming down steeply, so when you get a large vertical error even a small error in range can easily explain it.

Jon,

The shorter distance was measured with a leica rangefinder and gps confirmed, the longer on was by gps ? I feel fairly confident that the ranges are accurate.

Shawn,

I'll drop you a line to discuss this further after I check the points you mentioned. What does your pda say for a 1130 m target in the mentioned conditions ?

Thanks all for your thoughts. I just want to make that first shot count !

 

[Shawn Carlock]

I was within 1/4 moa of what you got on the program. While it is always possible it is a scope problem I would be really suprised if it was. Keep us posted. Do you have any issues at 500-600? What is the futherest distance you can find to shoot over flat ground?

 

[Down Under Hunter]

I was within 1/4 moa of what you got on the program. While it is always possible it is a scope problem I would be really suprised if it was. Keep us posted. Do you have any issues at 500-600? What is the futherest distance you can find to shoot over flat ground?

Shawn,

Good to talk today ! I feel alot better about things now. After analysing make sessions , I have concluded that conditions are at play, nothing more. I will shoot the rifle over 500 yards on flat ground this weekend. If the elevation is on, we will confirm everything.

Cheers to all again !

DUH