Density Altitude In Shooter App?

[Formidilosus]

On the extraneous stuff- spin drift, zero angle, aerodynamic jump, Coriolis, etc, etc. All of it is real, however those things have very little effect on hit rates in the terminal range of bullets (1,200’ish yards and in), but do add a bunch of noise that complicates the process and causes people to make mistakes- especially with an animal is in front of them.

Those things make up maybe 1-2% of error (if that) in any given shot inside of that 1,200’ish yard range, and almost all of that is spin drift. 0-900’ish yard shooting is best served by clean, simple, straight forward processes with as much extraneous noise removed as possible.

 

[Matt5266]

Shooter on my android isn't very user friendly and confusing to me..... but I've been known to not be very smart with technology

 

[TX_Diver]

On the extraneous stuff- spin drift, zero angle, aerodynamic jump, Coriolis, etc, etc. All of it is real, however those things have very little effect on hit rates in the terminal range of bullets (1,200’ish yards and in), but do add a bunch of noise that complicates the process and causes people to make mistakes- especially with an animal is in front of them.

Those things make up maybe 1-2% of error (if that) in any given shot inside of that 1,200’ish yard range, and almost all of that is spin drift. 0-900’ish yard shooting is best served by clean, simple, straight forward processes with as much extraneous noise removed as possible.

With what I got above after your help would you just run with that? Or anything else stand out that I should fix? I’ll mess with velocity truing tomorrow and see if I can get that last .1 mil to line up.

Also Thanks a ton for helping me simplify that stuff! I didn’t know I could get rid of those extra options.

In reality in the field I don’t plan on shooting past 400, so most of this is moot, but it was frustrating the crap out of me that it was that far off, and whether its 350 in the field or 750 at the range it’d be nice if I could trust the app (which seems plausible as long as I use it right )

 

[magtech]

I have run shooter for a long time. Based on your first post id say your sight height isn't correct. I can shoot my 6.5 under 1k yards without using da, without spin drift, but those do help farther out.


When i only shot 500 yards and under i didnt touch my bc. I just ensured my velocity was good ( having a quality reloading process helps maintain a consistent velocity)

When i shoot 500 yards here i use the acquire atmosphere from weather station and go shoot. The only thing i have to really worry about is the wind, and myself.

 

[TX_Diver]

I

I have run shooter for a long time. Based on your first post id say your sight height isn't correct. I can shoot my 6.5 under 1k yards without using da, without spin drift, but those do help farther out.


When i only shot 500 yards and under i didnt touch my bc. I just ensured my velocity was good ( having a quality reloading process helps maintain a consistent velocity)

When i shoot 500 yards here i use the acquire atmosphere from weather station and go shoot. The only thing i have to really worry about is the wind, and myself.

I will double check again. They are UM medium 30mm rings. Thanks

 

[TX_Diver]

Played with velocity calibration today and I am guessing I'm still doing something wrong.

If I put in 4.5 Mils at 610 yards and calibrate the velocity it gives me 2513 as my adjusted velocity (which is my actual velocity. But when I go to the solution it tells me 4.4 Mils at 610 and 3.2 Mils at 495.

If I put in 4.5 mils at 610 yards, AND 3.5 mils at 495, then I get 4.6 Mils at 610 and 3.3 Mils at 495 (so more mils at one distance and less at another)

At this point it seems like I should set my target with a waterline out there again and send 10 rounds (instead of 5 that I did last time) to really get a good drop? Maybe it's close enough but .3 mils at 495 is 5.3" which seems like enough to make a difference?

 

[TX_Diver]

I have run shooter for a long time. Based on your first post id say your sight height isn't correct. I can shoot my 6.5 under 1k yards without using da, without spin drift, but those do help farther out.


When i only shot 500 yards and under i didnt touch my bc. I just ensured my velocity was good ( having a quality reloading process helps maintain a consistent velocity)

When i shoot 500 yards here i use the acquire atmosphere from weather station and go shoot. The only thing i have to really worry about is the wind, and myself.

I took 1 7/8 to 1.9" for my height over bore?



Changing it to 1.8 in the app makes no difference if I calibrate using only 4.5 at 610. If I put in 4.5 at 610 and 3.5 at 495 then it gives me 2474 still for my adjusted MV, but drops of 3.4 at 495 and 4.6 at 610, so .1 less and .1 more at each range. Let me know what you guys think based on the pic. It's very possible i measured it wrong.

 

[atmat]

It's very possible i measured it wrong.

It’s not going to be your scope height. I just played around moving my scope height 0.3” up or down in Shooter, and I don’t see any difference until >750 yards.

Have you considered just starting over? Erase the gun and ammo from the app, and start from scratch?

 

[The Guide]

I took 1 7/8 to 1.9" for my height over bore?
View attachment 754070


Changing it to 1.8 in the app makes no difference if I calibrate using only 4.5 at 610. If I put in 4.5 at 610 and 3.5 at 495 then it gives me 2474 still for my adjusted MV, but drops of 3.4 at 495 and 4.6 at 610, so .1 less and .1 more at each range. Let me know what you guys think based on the pic. It's very possible i measured it wrong.

I put your basic information in with nothing extra. I'm close to what you shot just using the G1 and MV. See below.

Jay

 

[magtech]

If your scope height is correct and your mv is correct and bullet is correct then the basic setup of the rifle seems to be off..... or, your scope is jacked. You can test the scope if you make a holding jig and setup a tape at exactly 100 yards.

How are you acquiring your weather data? My closest westher station is 1 mile away, so I pull from that in the options. My gps altitude is nornally within 100ft of my current location, but sometimes its off 200 ft. If so, i adjust it to what i know my altitude is.

 

[magtech]

So i made a profile with the information from your first post. Here is the drop table. I use this everytime instead of the solution page. The only thing i did different is change your sight height to 1.6". It seems to have solved your conundrum. Is this correct (sight height), for your weapon. I do not know.

Here is what i put in.
1:8twist
Sight height 1.6"
Pulled the 147 eldm from library
Added 2513 mv @70f
Manually put in 102 temp
Manually put in 4000ft alt

Then i just went to table. No temp velocity or other special stuff was selected.

I AM NOT SAYING THIS IS YOUR SIGHT HEIGHT, BUT IT WORKS.

Sight height is center of bore to center of scope. I measure mine with calipers. To get center of scope just measure the barrell and divide it in two. Measure your gap from action to scope and measure from center bore axis to top of action. Add them up. Do it 4 or 5 times and decide what number/method you consider is the most accurate.

 

[TX_Diver]

So i made a profile with the information from your first post. Here is the drop table. I use this everytime instead of the solution page. The only thing i did different is change your sight height to 1.6". It seems to have solved your conundrum. Is this correct (sight height), for your weapon. I do not know.

Here is what i put in.
1:8twist
Sight height 1.6"
Pulled the 147 eldm from library
Added 2513 mv @70f
Manually put in 102 temp
Manually put in 4000ft alt

Then i just went to table. No temp velocity or other special stuff was selected.

I AM NOT SAYING THIS IS YOUR SIGHT HEIGHT, BUT IT WORKS.

Sight height is center of bore to center of scope. I measure mine with calipers. To get center of scope just measure the barrell and divide it in two. Measure your gap from action to scope and measure from center bore axis to top of action. Add them up. Do it 4 or 5 times and decide what number/method you consider is the most accurate.

Post 27 has a pic of my scope height.

I will try the above suggestion of deleting everything and starting over to make sure I didn't input something wrong too.

I'm also thinking that either my dope at 610 or 495 had to have been off as it seems like it's not possible for both to be valid based on the solution.

If they have added the 147 ELD-M to the library now that could help too. I had to manually put it in.

For BC selection, as I start so close to the lower limit of .697 would it make more sense to use .6620 for my BC?

I'll mess with all that stuff shortly and update in a bit.

 

[Nine Banger]

I'm also thinking that either my dope at 610 or 495 had to have been off as it seems like it's not possible for both to be valid based on the solution.

I was getting incorrect drops between 300 and 825 with 147 ELD. I've futzed with it the last 3 range trips and I'm still not "there". I also experienced what you did where I manually enter known drops and "use MV" and then go back to the table and it will change one value I entered but not the other...

The app accepted my input for 825 but not 400. I'm still seeking the real drops for 500 and 600...we don't have 700 at my range. I ran out of time to find them at last range session.

 

[Overdrive]

May not be anything wrong with your APP. Have you considered that it was Mirage throwing your shots low, it's pretty common and I find it hard to believe that with a 102f temp that there was no Mirage. I've sat at the bench on hot days looking thru my scope with a cooled barrel and could see the target "dancing" because of Mirage. I personally shoot early mornings to avoid Mirage, especially when collecting data or checking my dope.

 

[TX_Diver]

May not be anything wrong with your APP. Have you considered that it was Mirage throwing your shots low, it's pretty common and I find it hard to believe that with a 102f temp that there was no Mirage. I've sat at the bench on hot days looking thru my scope with a cooled barrel and could see the target "dancing" because of Mirage. I personally shoot early mornings to avoid Mirage, especially when collecting data or checking my dope.

That's possible. My stock was delivered in the afternoon so that was my chance to go shoot. This weekend I'll get out there earlier and see what happens.

I think my best bet at this point is to find somewhere to shoot 7 or 800 and put 10 rounds on a waterline and go from there (vs 4 & 5 that'd I'd done at each distance previously).

How far off are you at 400 based on your 800 yard correction?

I wouldn't think it'd make much difference at the ranges I'm actually going to shoot at, but searching online to confirm my length and BCs, etc. for the 147 ELD-M I did find a lot of "complaints" of BC variability on that bullet.

If I need to shoot the last 200 or so I have loaded up to get this sorted out I will but hopefully I can do it in less than that!

 

[atmat]

That's possible. My stock was delivered in the afternoon so that was my chance to go shoot. This weekend I'll get out there earlier and see what happens.

I think my best bet at this point is to find somewhere to shoot 7 or 800 and put 10 rounds on a waterline and go from there (vs 4 & 5 that'd I'd done at each distance previously).

How far off are you at 400 based on your 800 yard correction?

I wouldn't think it'd make much difference at the ranges I'm actually going to shoot at, but searching online to confirm my length and BCs, etc. for the 147 ELD-M I did find a lot of "complaints" of BC variability on that bullet.

If I need to shoot the last 200 or so I have loaded up to get this sorted out I will but hopefully I can do it in less than that!

I think generally Hornady BC’s are good. Your bullet length is irrelevant if you’re not doing any of the advanced ballistics calculations.

 

[Formidilosus]

That's possible. My stock was delivered in the afternoon so that was my chance to go shoot. This weekend I'll get out there earlier and see what happens.

I think my best bet at this point is to find somewhere to shoot 7 or 800 and put 10 rounds on a waterline and go from there (vs 4 & 5 that'd I'd done at each distance previously).

How far off are you at 400 based on your 800 yard correction?

I wouldn't think it'd make much difference at the ranges I'm actually going to shoot at, but searching online to confirm my length and BCs, etc. for the 147 ELD-M I did find a lot of "complaints" of BC variability on that bullet.

If I need to shoot the last 200 or so I have loaded up to get this sorted out I will but hopefully I can do it in less than that!

It isn’t BC variability- you are chasing your tail with the little stuff.

Get a no kidding 100 yard zero without barrel, ground, or target mirage.
BC- .697 G1
Enter velocity
Enter sight height
Use DA.
True at 600-800 yards.
It will be correct from muzzle to your trying range.

Anything else is something wrong with your system, zero, wind, mirage, etc., somewhere- it isn’t that you are using a Mach 2.25 BC, AJ, spin drift, the angle of the light, nothing. Those things cause TINY errors.

 

[Nine Banger]

How far off are you at 400 based on your 800 yard correction?

147gr ELD 18" barrel

400: shooter said 2.1 mil, hits occured at 2.2 mil

500 shooter said 3.1, hits occur at 3.3 and 3.4 Mil

600 shooter said 4.1, hits occur at 4.4 mil

800: shooter said 6.5, hits occur at 7.8 mil

muzzle velocity was corrected.

I was suspecting BC is innacurate or variable too but my knowledge is in this subject is that of an advanced beginner.

Shooter accepted 7.8 for the MV correction but my 400 yard correction is ignored and wont change and says 2.6

 

[Formidilosus]

147gr ELD 18" barrel

400: shooter said 2.1 mil, hits occured at 2.2 mil

500 shooter said 3.1, hits occur at 3.3 and 3.4 Mil

600 shooter said 4.1, hits occur at 4.4 mil

800: shooter said 6.5, hits occur at 7.8 mil

muzzle velocity was corrected.

I was suspecting BC is innacurate or variable too but my knowledge is in this subject is that of an advanced beginner.

Shooter accepted 7.8 for the MV correction but my 400 yard correction is ignored and wont change and says 2.6

Close the app down and relaunch. That may fix it. Also, I’m supposing due to rounding errors, sometimes when you do velocity calibration in the app, it will be .1 mil off on the chart. Then you go in and manually modify the MV to get it to change.

 

[Nine Banger]

It isn’t BC variability- you are chasing your tail with the little stuff.

Thanks Form. Starting over with a new profile was my plan to eliminate errors.

OP: I acknowledge that all my data could be mirage as well...its in the 90's here and 92% RH and raining daily at this time. I'm shooting prone over a vast patch of mowed grass, so the scope is probably 10" above the wet grass.