I noticed that my FX Royale 500 POI changed after a few minutes when I went outside. It was shooting a decent group at first, but after a few minutes it was shooting almost an inch low and inconsistent. I shot a few over the chronograph and there was no change. My house was fairly cool with the AC on and outside was hot and very humid. Anybody else notice similar results?
Effect of changing temp & humidity
- Thread starter deroosea
- Start date
Its common to see some change do to temperature changes. Let the gun and scope stabilize at the new temperature for a few minutes before shooting. Metal especially expands when it gets hot so as its warming up things are changing size until it all gets to the new temperature. And different materials expand at different rates so its not surprising that poi will shift around until everything stabilizes.
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I have noticed that in my 25M range, that one day I was shooting while it was warm and humid out, actually was misting rain. My POI was higher than just the day before when it was dryer and cooler air. From my research this proved to support that cool air is denser and that humid warm air is less dense, thus providing less resistance to the pellet as it travels thru the air stream, therefore less drop caused by resistance and hence a slightly higher POI. Then again, I could have been the culprit as well. Who knows, but I did notice it and thought it was an interesting phenomenon to witness.
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Humidity, no. Not at all at normal airgun ranges. Temp. change, could well be. And if it is temp change it could be, just the rifle, just the scope, both. Different metals expand/contract at different rates. You'll see a lot of people at matchs with temp strips (like for a fish tank that change color) on their rifles or scopes. SOME temp shifts (that's some rigs) are very repeatable, I have a friend who add's 4 clicks to his scope at 84 degrees, works everytime. Some are not as easy to nail down and or continue to change.
Pretty easy to check just make sure it's zeroed cool it down to 40 or so and take it shooting on a hot day with a decent thermometer.
IF that's your problem, maybe try different scope rings, different scope then if you still have temp shift put a sticker thermo on it and learn where to click depending.
John
Pretty easy to check just make sure it's zeroed cool it down to 40 or so and take it shooting on a hot day with a decent thermometer.
IF that's your problem, maybe try different scope rings, different scope then if you still have temp shift put a sticker thermo on it and learn where to click depending.
John
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When I bring my rifle outside from the a/c home, the rifle is covered in condensation. Does this condensation hurt the rifle in anyway? When I take my AR15 out I could care less about moisture, but PCP's seem more delicate and I'm still very new to air rifles.
CJ
CJ
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Hmmm... turns out that cleaning the rifle after ~400 shots helps too. After cleaning my rifle I was back to pellet on pellet at 35 yards (~1/2 inch groups). Go figure. 
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