How do you...adjust for large temperature changes

[Smok3y]

How do you all adjust your air rifles throughout the year as the temperature changes? I guess the same goes for you guys that live in various places around the world and then travel to a big international tourney.

For example, it is March and you have your gun dialed in but the highs are only around 70* at best. Now it is July and 90* or more every day and your pellets have gained 20FPS and are not shooting quite as well. 

Do you make small adjustments to the reg, just the hammer spring, or do you go through the effort of adjusting the reg and hammer spring as well to keep that perfect balance? I started thinking that the 10 FPS increase when we got into the 80s was causing a bit of change, and I’m fairly positive the 20 FPS is affecting things now in the 90s.

How does one deal with that with a Daystate without the adjustability? I didn’t have my Daystates long enough for that to become an issue, but I have often missed them. Running into this recently has me wondering how I would have adjusted with those rifles too. 

 

[elh0102]

Smoky, I believe you might be overthinking it a bit. If it's hot enough to push up velocity, and you can't make a tuning adjustment, just make a POI adjustment and shoot. This isn't something restricted to air guns, basic ballistics.

 

[JCD]

Scopes tend to add more to temp shift than the guns, at least in my back yard and the FT shooting I've done. I've shot with folks who have marked there scope wheels at 'hi' and 'low' temps for distances where it matters, and sometimes in between But for me, dead of winter (call it 30 degrees) and middle of summer (call it 90) are a couple clicks on the turrets. 

 

[Smok3y]

Maybe I am. I was just thinking that the increase in speed may affect it more than just a little POI. As often as you see everyone trying to find that perfect balance, a 20 FPS change is often enough to get a rifle pellet combo dialed right in.

Seems like a bigger issue for the competition guys than it is for a back yard guy like me. Just made me curious how people deal with it.

 

[Smok3y]

Maybe it is no issue at all. Sounds like I was just thinking too hard. Never shot the same rifle all year round before.

 

[qball]

Shouldn’t be an issue, the trajectory will vary a little so regardless of temp you should re-zero all the time anyways. 

 

[elh0102]

I shoot air rifles only casually, for fun and pesting. But I shot both RF and CF bench rest for years. At the precision accuracy level, tuning is a daily challenge, since matches are won or lost at very small differentials. And yes, temperature changes are an important variable. I remember reducing powder charges by 1-2 grains on higher temperature days. But in terms of practical accuracy, squirrel head accuracy, these temperature changes are not generally significant. Chasing the ultimate accuracy can be a maddening endeavor, which is why I so enjoy my air rifle plinking. If I can't hit it, I get a bigger target!