Leishy loosing air

Once the gun is folded it is cocked so there is no difference in the sealing parts be it folded or left cocked while straight, so not sure why it would "leak" a different amount. Are you sure it isn't temperature related? Being such a small cylinder my leshiy appears to be greatly affected by temperature changes. I fill it up to 250bar in evening and when I left the house it was still 250. I check it about a hour after hunting in about 25degree temps and the pressure was 225bar. When the temp got up to about 50 it was up to 240bar.

Fill it and let it sit over a couple of days and see if it keeps going down the same each night.
 
I first witnessed that, as I aired up the gun to 236 bar, left it in a colder part of house and got a 205 reading a day later. The next day 192, cocked it and loaded pellet for pests raiding garbage cans. The gun unshot then read 140 two days later. I shot the pellet left the gun for several days just checked and was at 5 on the gauge shot the gun and got a weak sound. What size O rings do I need to do the whole job,