This gotta beat them all- 500yards Big bore airgun shoot

[johan_portin]

Hi flims!

Actually I have had the gun for about four months but since I’m suffering from a severe condition of poor judgement I haven’t been able to test it much on longer distances. When I bought the gun from param… I also bought a scope, a Leapers 3-12*44 but with parallax set at 35yrd – why? Poor judgement! So I used this scope for a while and realized it wasn’t good enough so I ordered a new one 3-12*44 AO and a leapers 8-32*56 AO, chrono, bipod and some more stuff… the 3-12 scope wasn’t in stock and they told me it could take a week or so; so I waited. After six weeks I removed the scope from my order and they sent it to me.

So after two months I finally got my shjt – cuz I have bad judgement.

This was about two weeks ago, at this time I had to go on business trip by car – in this season the weather conditions here in Norway can be very challenging for drivers since the roads mostly are covered by ice… due to poor judgement combined with an icy road I now haven’t got any means to go anywhere to shoot – my bmw is scraped…

[flims]

tnks for you post. i'm curious to see how the air rifles work in such cold temperatures as you speak of. Are they still consistant? i never shot mine at less than 14degrees celcius i think. in summer i sometimes get strange numbers if it bakes in the sun.pressure soars ofcourse.
For the price i think its hard to beat Falcon optics esp. the new Menace range. some friends of mine are vry pleased with them esp. with their Mil turret that matches the reticle perfectly.

[johan_portin]

Low temperature doesn’t affect pcps much, I just fill the to the same pressure and shoot. But temperature differences can be bad for a pcp since air expands with higher temperature. The expansion of air is fairly linear and can therefore easily be calculated with the absolute temperature (the Kelvin scale) 0 degrees Celsius is 273,15 in Kelvin. So if I fill my pcp to 3000psi outdoors at 0 Celsius and the bring it inside to room temperature it will have 3200 psi - at 20 degrees Celsius (from 0) the volume of gas has expanded 20/273,15=0.0732 roughly 7%.

In your case filling the gun indoors at 20 degrees and the leaving it outside to cook in the sun for a while so the black tube reaches 80 degrees is bad! At this temperature you will have 3660 psi in the tube.

Its good to be aware of this, especially if you leave the gun fully charged in a car on a hot day...

For CO2 its totaly diffrent - you can shoot with CO2 at low temperatures... well you could but it sucks

[flims]

thanks for the explanation on airpressure johan.

In your case filling the gun indoors at 20 degrees and the leaving it outside to cook in the sun for a while so the black tube reaches 80 degrees is bad! At this temperature you will have 3660 psi in the tube.

Its good to be aware of this, especially if you leave the gun fully charged in a car on a hot day...

with regards to this, i dont leave it to bake in the sun but if im on the range for 4hours in summer and its 38degrees Celcius in the shade the gun is still getting warm. We do try to avoid leaving them in the sun altough the background temperature is still very high here in Summer. usually people leave about 10am as it starts getting unbearable but i did spend my fair share under the mediterreanean summer sun then run to the Sea
the pressure would indeed rise and sometimes i would get higher velocities altough i was never sure if the higher velocities are because of the environmental conditions or because of the tube of the gun per se' as happens with external ballistics in firearms.

i fill the gun on the range as with those guns you need to lug the cylinder with you. i fill about 10 times on a range session if left in the car the o ring that is there to prevent over pressure will just tear and it starts loosing air

[el maipino]

Just found this thread. Excellent.

I am about to order a shinsung dragon slayer .50 cal airrifle on friday and hope to have it by within the week.

I will be trying out the 200 and 225 grain pellets from pyramydair in the US.

No exp whatsoever with bigbore but been dying to have one for ages and now I am no longer in the UK and dont have to worry about fac laws etc I am going to get one.

I will post some pics and video as soon as I can.