Daystate Air Ranger 2012. Pressure changes query???

[Whizzie 38]

Here we go folks, sold my Air Arms S400 TDR .22 last year & put many a hard earned coffer into my supergun. I have to say, I am incredibly impressed with the air ranger. Nothing I can say here really would do it true justice. It is a superb piece of kit, that i'm seriously happy with.

 

However... Here's my recent dilema. Everytime, i go out, i check the zero of the rifle is pellet on pellet @ 35yds. After a few hours of rabbiting on my permission, with nothing seen & an empty game bag, i put some training time on the range. All good practice. The rifle has a sweet spot starting at about 176 bar & to charge it over this is simply a waste of pellets. After sending 40 - 50 pellets through it, the zero was suddenly lost, and the rifle started hitting a full 6" above the previous zero @ 35yds. it remained consistent for 10 shots. Bemused, I reloaded the mag & put another 10 through. Same result. The scope / rifle wasnt knocked, there was no change of anything at all. After re zeroing the rifle & sending another 30 - 40 pellets through it, the charge indicated about 110 - 120bar, well within the sweet spot. The rifle then adjusted back to its original zero point requiring the appropriate adjustment to the scope....

 

This has given me some food for thought, as the only conclusion i can draw, rather strangely, is that of the weather. On both occasions when this has happened, the rifles gone out with a full charge & performed normally. However the early start has been rather cool & the mid day temps have reached over 22.5 degree's C. With the mid day sun & increase in ambient temperature, could this cause an increase in pressure & increase in air delivery to the chamber when the trigger is pulled??? (Warm air expands / cold air contracts etc.) However, my 230 bar divers bottle is stored close to the manifolds for the underfloor heating system, so its pretty warm there too, and I would say about 21 - 24 degree's C. So if the rifle is charged at that temp, and then exposed to cooler air, and then the sun / ambient temp increases, could this account for the change described above??? The Air Ranger isnt regulated, but then the daystate air release system is so consistent, it doesnt need to be.

 

Any thoughts???

 

Whizzie

[Whizzie 38]

Having played about with this.... You're not going to believe it, See above image, you can see my rifle and my home-made bipod. It works fine and is a cheap and cheerful way of Laying in the prone position and getting the results without putting any bipod fixtures into my lovely Minelli stock.

 

However you also notice the rifle isn't equipped with a body bottle/barrel support, as seen on the air ranger etc. The initial shots were taken using the bipod underneath the buddy bottle, and then a lower profile was adopted and the bipod placed forward of the buddy bottle, under the barrel.... The weight of the gun and forward position of the bipod under the barrel caused a lift, Resulting in the problem discussed above.

 

You live & learn...

Edited September 24, 2012 by Whizzie

[AR177 588]

The barrel is free floating, resting it on anything will throw off your zero

 

you can get the barrel supports online if you really want one, think they are about £26

 

ATB

 

Adam

[Whizzie 38]

I can't believe I was so naive to miss something so obvious, but then, its something no doubt other folks will do, or hopefully now avoid!

 

Cheers

 

ATB

 

Whizzie

Edited September 26, 2012 by Whizzie