shooting at different Temperatures

Forums General Discussion shooting at different Temperatures

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    DAVEFISHING
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    Have any of you tested your FPS at different Temperatures ? Are springers more prone to temperature changes than PCP?  My Diana Stealth has a 60 FPS drop from 60 deg.to 100 deg.

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    SvilenP
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    "Strelok +" => As the temperature increases, the speed and power increase and vice versa, as the temperature decreases.

    With my measured Hatsan 125 data with a chronograph, it gives me the top score when changing the temperature (in the program).

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    DAVEFISHING
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    SvilenP

    "Strelok +" => As the temperature increases, the speed and power increase and vice versa, as the temperature decreases.

    With my measured Hatsan 125 data with a chronograph, it gives me the top score when changing the temperature (in the program).

    Do you have your data to show me?

    my data.

    60 deg 700 FPS.

    78 DEG 690FPS

    90 DEG. 670 FPS.

    102DEG  655FPS

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    bigdaves40
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    Davefishing, my thought is with a springer, you are compressing cold dense air 60deg Wich may pushing the pellet faster as you show. And hot thin air less fps. Kind of like a high compression race engine, cooler the air going in, more compression and HP. Just my thoughts Dave.

    Note: pcp will probably shoot faster in the heat, inturnal air source. 

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    SvilenP
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    My temperature influence data is only theoretical (from the program). I have not yet measured this impact on terrain. There may be other results in practice…

    By the way, the difference that the program gives me is (25 deg Celsius and 40 deg to 50 meters): V: 142.3 m/s and J: 10.5 => V: 145 m/s and J: 10.9

    So the difference is not great at Power but rather at Speed…But again, I repeat that it is theoretical…

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    Scrufhunter
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    I can tell you from experience temp and elevation play a role..  when its really hot 100+ the riasing heat thermals effect the trajectory. its like wind. 

    When I lived up a mountain, and drove down to my friends orchard along the river about 1000ft elevation change the temp was always cooler by the river, and I would have to resight in.  At the time all I used was gas rams.  I remember in the winter months when there wasnt much of a temp difference between the two places my POI didnt shift as much if at all really

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    SvilenP
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    Yes, altitude affects a lot, but here it is a matter of whether, with just a rise in temperature at the same altitude, the speed
    (respectively power) in what direction will it change?

    Theoretically, I see that the speed (and power) is increasing when the temperature rises while the colleague is going back?

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    Scrufhunter
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    I can say when I put my rifle away in the hot of summer and pulled it out in the mid fall 30-40 degree difference the riffle needed to be sighted in again…kept at same altitude, the POI changed. Although it very well could have been the fact I hadnt shot the gun in about two-three months or so

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    DAVEFISHING
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    SvilenP

    Yes, altitude affects a lot, but here it is a matter of whether, with just a rise in temperature at the same altitude, the speed
    (respectively power) in what direction will it change?

    Theoretically, I see that the speed (and power) is increasing when the temperature rises while the colleague is going back?

    AS temp. goes up the speed goes down.

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    Scrufhunter
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    I would believe that in very hot places, where you can see the shadows of the heat rising/thermals that it would effect the trajectory/travel of a pellet in the same way as wind  in a vertical manner….How does high humidity vs no humidity effect a pellet in travel? I would imagine that extreme cold would effect it aswel. A pellet traveling threw extremly cold air, i'd imagine it would take on frost and dimenish the range and effect the POI from shot to shot

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    SvilenP
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    In our forum colleagues have always written that winter speed is falling and for this reason I think it is logical that at higher temperature the speed slightly increased as the program shows. But I have not yet observed what difference there will be, for example, 15 degrees Celsius and 40 …

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    DAVEFISHING
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    Temp. has change my left and right POI. I have showed this on here before but have not got a response. I took the gun back to AOA where i bought it for evaluation. They only have a 25yd target inside.

    5AM 70 deg

    9AM 100 deg.

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    John_in_Ma
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    DAVEFISHING

    Temp. has change my left and right POI. I have showed this on here before but have not got a response. I took the gun back to AOA where i bought it for evaluation. They only have a 25yd target inside.

    5AM 70 deg

     

    9AM 100 deg.

     

    Have you tried shooting it without the scope at those temps? Have you tried a different scope? Did you leave the gun outside to warm up? Was the wind the same when both groups were shot? 

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    SvilenP
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    Without much understanding, I think the problem of this difference in the target is not only due to the difference in temperature …

    Differences in summer / winter, differences in wind and no wind – Ok, but such a difference only by the temperature … hardly …

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    DAVEFISHING
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    this is the third scope I have put on  UTG 4-16×56 Bubble Leveler AO Rifle Scope  . no open sights for it. it stays out side all the time. on my shooting stand or in my boat.

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    SvilenP
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    Ok but shooting on the targets with the same pellets (brand) ? and under the same conditions (meaning at the same time, wind, place etc and the only difference is temperature)?

    PP. Which bench is a rifle what is the model and the brand? Are you satisfied with the size and exact positioning of the rifle?

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    DAVEFISHING
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    Glad I did not leave it in there yesterday. We had a bad storm come threw and a culvert from the neighbor blew into my barn. smashed my shooting stand, broke my boat prop. Ordered a new stand today and prop.

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    jking
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    Wow Dave, that must of been a heck of a storm. About par for the desert though, going from bone dry to flash flooding in minutes. I was going to say it's the heat affecting the droop of the barrel but if the velocity is dropping that much it sure looks like it's just the speed causing the difference in POI. I've only had one break barrel way back when so I don't know much about them. I know when my PCP's get good and hot they can shoot 20fps faster for a while. Maybe someone with the same gun will chime in. Keep us posted on what you find. By the way, have you shot it throughout the morning to see if it's a steady drop in POI as well as the velocity?

    Good luck

    Jimmy

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    SvilenP
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    I'm sorry for the damage!
    There is nothing to do against nature …

    What kind of stand will you take?

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    DAVEFISHING
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    this is what I ordered.

    Goplus Portable Shooting Table Bench Seat with Adjustable Gun Rest.

     

    Caldwell DeadShot Boxed Combo (Front & Rear Bag)

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