although like a lot of things it could just be a placebo 
Interesting…I do in the winter months put my cartridges on the radiator the evening before and that does seem to help somewhat. Especially if they have recently come from the shop
Out of curiosity - Is that legal in the UK? At my end of the channel a certificate can be (and in several cases I know of was) revoked for leaving munitions unattended. It has to be kept in a safe, or has to be in the shooters personal possession. If in a bag prior / after shooting where the shooter can see the bag: Okay. In a locker in your gun club? Okay. In the boot of your car, while car is in the parking lot? Not okay. Wife finds a 12 G or even a 22 cartridge in your shooting jacket, places it on top of your safe and you happen to get a FEO visit? Trouble.
I’m assuming you mean as “long term storage” ? I.e for a couple of weeks ? If this is the case would be interesting if you where to take some indoors and give them a little radiator treatment before your next outing and see if you can see a difference ?
It’s the plumbing that’s the issueI don't think I'd want to haul a radiator around with me thanks
In my experience of “confetti” it appears to be more unburnt powder than premature breakdown of the wad. Especially when looking down the barrels after. Lad who I shoot with got a slab of black gold on the way to a shoot and the box felt damp. Like cold to the touch never seemed to warm up if you know what I mean and after putting 100+ through his gun it looked like he’d been burning coal
Both sad and glad it isn’t just me. It’s hard to get fiocchi near me as my local places are staunch Hull and Gamebore. With a couple of slabs of Eley if they are feeling exotic. So I have to order from Just Cartridges.
