Velocity adjustment with sig kilo

[jimbires]

how far are you guys able to range with your 2400abs ?

I'm ranging steel plates . I think it's been 100% at 1480 yards . I'll say I'm about 80% able to range 1680 yards about a 24" sq target . I got it to read one time at 2045 yards 24" sq target . forget it at 2375 yards about 34" sq target . all targets painted gloss white

 

[808mike]

Jim i think you hit the nail on the head! Same 1 moa difference and im pretty sure my cousin put the inputs in at sea level in his office and we shot at 4k.

 

[Tucker65]

I set up my 2400 abs a few months ago . it was in the 90*'s when I shot , I brought my chrony info home and plugged all my info in while I sat in A/C at the kitchen table . my first trip out with the rangefinder I was running about 1 moa off . I shot chrony readings again , and input them right there in the field , problem solved . the rangefinder has a built in weather station , so it needs to see the velocity under those conditions .

I'm not sure this is correct. You can only load 4 rifle profiles into the range finder at a time. I have a dozen or more profiles and change them in the range finder all the time from hunting rifle to varmint/target rifles and once I've entered the chronograph data in the app I'm good. If I shoot a powder that is temperature sensitive I'll put those parameters in if I know the velocity differences while shooting at different temperatures. If what Jim is saying is true you'd have to enter all the data for your rifle profile in the app at in the field while shooting and then sync that profile on the range finder. Once synced it would need to stay there to be accurate unless you syned it again in the same conditions.

 

[John Klingenberg]

I'd agree to adjust the velocity so it fits. The point of shooting is to hit. As long as its correct in actual shooting you've solved it.

 

[jimbires]

I'm not sure this is correct. You can only load 4 rifle profiles into the range finder at a time. I have a dozen or more profiles and change them in the range finder all the time from hunting rifle to varmint/target rifles and once I've entered the chronograph data in the app I'm good. If I shoot a powder that is temperature sensitive I'll put those parameters in if I know the velocity differences while shooting at different temperatures. If what Jim is saying is true you'd have to enter all the data for your rifle profile in the app at in the field while shooting and then sync that profile on the range finder. Once synced it would need to stay there to be accurate unless you syned it again in the same conditions.

Why Ballistic Calibration Should Only Be Performed In the Field

Why Ballistic Calibration Should Only Be Performed In the Field: https://youtu.be/sMNcolFdfP0 The Applied Ballistics Engine is advanced enough that it takes in to account the target information and environmentals at the time you perform a Muzzle Velocity or Ballistic Calibration. Due to the...

www.longrangeonly.com

 

[jimbires]

Jim i think you hit the nail on the head! Same 1 moa difference and im pretty sure my cousin put the inputs in at sea level in his office and we shot at 4k.

don't forget to do the compass calibration too .

 

[808mike]

don't forget to do the compass calibration too .

Awsome info thank you!
I feel optimistic now ill let you guys know how it goes tomorrow.

 

[Tucker65]

I had questions about shooting at different altitudes and weather conditions and what to do about calibration. I asked DocUSMCRetired about it and he said as long as I zero my rifle at 100 yards I'd be good. I couldn't grasp the idea of shooting at sea level and then at 6000' how it would work. He explained to me that if zeroed at 100 yards the bullet isn't in the air long enough for any atmospheric conditions to affect it. Then when you shoot at any elevation or weather condition the range finders sensors determine the correction based on your 100 yards zero which should be good. That being said, if you're zeroed at 200 yards the elevation and weather conditions could be skewing your range finders corrections.

 

[jimbires]

I don't think a 100 yard zero will vary much due to weather . you set up this rangefinder under any conditions or elevation and it knows this . then when used at a different location , or even a different day , this rangefinder will correct it's dope to match the conditions that it is presently in . I'm going by memory ; on the app , I think at the bottom there is about 5 lines that you can input more temps and velocities . I think these are to help the rangefinder know more conditions to help with more accurate outputs . probably way more needed with temp sensitive powders .

 

[Tucker65]

I don't think a 100 yard zero will vary much due to weather . you set up this rangefinder under any conditions or elevation and it knows this . then when used at a different location , or even a different day , this rangefinder will correct it's dope to match the conditions that it is presently in . I'm going by memory ; on the app , I think at the bottom there is about 5 lines that you can input more temps and velocities . I think these are to help the rangefinder know more conditions to help with more accurate outputs . probably way more needed with temp sensitive powders .

Yes, a 100 yard zero won't make any difference from sea level to 10,000 feet but if he's zeroed at 200 yards at sea level and shooting at 4000 feet that could be his 1 moa error.

 

[jimbires]

correct . if I understand 808Mike correctly ; they shot and gathered velocity info at 4000' in those weather conditions on that day . THEN at sea level , in the comfort of his climate controlled office , he set up the rangefinder . so the range finder thinks they shot 3000 FPS , at sea level , in a 70* ??, low humidity environment .

if the rangefinder was set up in the field , the rangefinder should account for the change in altitude , temp , humidity ..... .

 

[Tucker65]

correct . if I understand 808Mike correctly ; they shot and gathered velocity info at 4000' in those weather conditions on that day . THEN at sea level , in the comfort of his climate controlled office , he set up the rangefinder . so the range finder thinks they shot 3000 FPS , at sea level , in a 70* ??, low humidity environment .

if the rangefinder was set up in the field , the rangefinder should account for the change in altitude , temp , humidity ..... .

This is where the range finder and its instructions are not very intuitive. Does the ranger finder take all those atmospheric readings to calibrate itself every time you sync a new rifle profile. If that's the case do you then need to get accurate new velocity readings where you're going to be shooting every time you want to load a rifle profile.

The app where all your profiles are created doesn't know anything about your environment. I guess that is why I was instructed to zero at 100 yards to take all the atmospheric variables out of the equation. All I know is that I zero all my rifles at 100 and sync profiles back and forth all the time. My drops have been really close using the AB curves that Litz verified. I've shot these rifles out to 1500 yards with only minor tweeks to the curve and some of that could be driver error behind the rifle.

 

[808mike]

correct . if I understand 808Mike correctly ; they shot and gathered velocity info at 4000' in those weather conditions on that day . THEN at sea level , in the comfort of his climate controlled office , he set up the rangefinder . so the range finder thinks they shot 3000 FPS , at sea level , in a 70* ??, low humidity environment .

if the rangefinder was set up in the field , the rangefinder should account for the change in altitude , temp , humidity ..... .

Just to confirm...Data was inputed at sea level a few days before gun was shot at 4000' and reconfirmed velocity . zero range was 214 yards for gun and range finder.
Two range finders and shooter app said 2.5 moa @ 340 but we had to dail 3.5 and @ 540 range finders and app said 7 moa but we had to dail 8 moa.
I told my cousin i would write +1 on the range finder lens so he would see it while ranging and he was good to go..

 

[jimbires]

This is where the range finder and its instructions are not very intuitive. Does the ranger finder take all those atmospheric readings to calibrate itself every time you sync a new rifle profile. If that's the case do you then need to get accurate new velocity readings where you're going to be shooting every time you want to load a rifle profile.

The app where all your profiles are created doesn't know anything about your environment. I guess that is why I was instructed to zero at 100 yards to take all the atmospheric variables out of the equation. All I know is that I zero all my rifles at 100 and sync profiles back and forth all the time. My drops have been really close using the AB curves that Litz verified. I've shot these rifles out to 1500 yards with only minor tweeks to the curve and some of that could be driver error behind the rifle.

I think the app must know the conditions you were shooting in . I'm assuming the range finder gives that info to the app when they are in sync .