StrelokPro Pro weather data

[StarlingChaser]

Not sure if this is under the correct category but relates with ammo directly. I have used StrelokPro for a while now but have never really messed with weather data. So a couple of questions for you guys who would know. 1st does weather data change the point of impact for air guns (slugs) that much, let’s say I zero at 50 ant shoot at 120 and I zeroed at 75 degrees and shoot later at 30 degrees. 2nd to truly use BC or FPS correction it should be done at the same time as we zero at the same weather conditions. Now I zero at home one day and do a correction maybe a week later when I can shoot further and the weather is totally different. I think this is causing me issues. 3rd are the more serious shooters getting there fps at one temp then at another temp later to set their temp sensitivity? 

 

[8thman]

My impact mk2 will looses speed as temperatures drop about 10fps for every 10 degree drop, an example at 85 degrees the gun shoots 900fps and at 75 degrees it’s in the 890fps and at 65 degrees 880fps. Now with that being said the other day It was 45 degrees and it was 875fps and I do not know if it will drop lower as gets colder or if it reaches a bottom out point? I believe at 90 degrees it may be at 910 degrees but I don’t know?when I zeroed the gun at 80 degrees at one high of true center at 50-75 and 100 yards ,as temperatures drop my poi drops and when I last shot it at 875 the 36.2 slugs dropped to true center of my target. After deer season I will conduct more tests, I got my impact mk2 this past July and after some break downs I have set where I believe it to be. Knowing about the temperature variation making the poi one inch high at 80 degrees every thing so far are falling right in place for me but normally I shoot a lot in my yard out to 120yds , I sometimes go through 200-500 nsa 36.2 slugs in a week, if weather allows and I’m not hunting (note I also deer hunt in my yard). Good luck to all!

 

[StarlingChaser]

Your info reflects really close to what I am seeing. I can’t shoot that much right now so keep us informed on your results. This is kind of an eye opener for me. Never would have dreamed weather would make such a big difference in air guns. 

 

[8thman]

The way the gun is tuned gun now and that includes the scope adjustments I have had no reason to change for the last 900-1200 shots with slugs. The wind I just play according, and I shoot a three group to check the environmental changes generally if their little wind I’m only dealing with a one inch drop so far at the most. Also if the sun is hitting the black gun it seems to shoot a little faster but I have not confirmed that with the chrony yet,this time of year towards evening temperatures drop ten degrees in short periods of time.

 

[Airgun-hobbyist]

I use the SrelokPro edition and still have not used the weather portion of the app either! I didn't think it mattered much with our relatively short ranges, but I'm sure it does a little. When saving the ballistic data I do manually change the temperature to what it was when shooting or chroning just so there are some written log of temperature. It would seem that you could test the theory of whether or not weather effects POI by manipulation of the weather data and seeing if it effects the projected point of impact. I do trajectory tests based on bullet weight and FPS changes with the Pro app and the results are usually correct. 

 

[StarlingChaser]

Yes I have been playing with #s and I am really surprised. Here are some results. My last shot I took when out shooting starlings was 103 yds so I will use that. My zero is 50 yds shooting 29g hollow point boat tail slugs at 974 fps. I zeroed at 46 degrees so at 103 yds. Strelok  told me my hold over is 1.86 mil. I used 1.5% change for weather because this seemed to be close to what a few people have said (this is the part I have not proven yet  by actual shooting). Anyway if the only factor I change is the current temp, at 103 yds. and 32 deg. It says my hold over is 2.02 mil, at 90 deg. my hold over is 1.40 mil. At 103 yds. that is 2.3" difference between 32 deg. and 90 deg. for this slug. I dont think this can be so but I have my work cut out for me to do real world testing. Do any of you guys have a weather sensitivity % that has interred different fps at at least 2 temps. If 1.5% is close then I have been missing a big part of Streloks formula but would also explain a lot of questions. This didnt even take humidity and pressure into account. Still learning!