HW77K .22, HW100KT .22, HW95K .22. AA TX200 MK3 .22. AA S410 MK3 .177. HW80 .25 HW30S .22. Pistols: Walther CP88 .177, Hatsan Mod25 Supercharger .22, HW45 Silver Star .177, Webley Alecto .177, SMK Victory CP2 .22
Before it closed..my local gunshop used to put the bottle into a bin full of water to keep it cool and also top up after waiting 15 minutes or so.
Chairman Emley Moor F.T.C. 2023 - Misfits champ, HFT extreme champ, NEFTA hunter champ, Midlands Hunter champ, UKAHFT champ.
https://sites.google.com/site/emleymoorftc/contact-us
I wrap my bottle in a duvet, with a couple of picnic freezer blocks and leave 'em in the back of the car for 1/2 an hour before I set off for the dive shop.
That means the cylinder is at about 5 celcius when I arrive, ready for a full fill, without the cylinder ending up warm and under filled.
The laws of physics are always useful.