I'm looking at different ways to cool a barrel as well. There is one thing that I learned in life is that if something looks stupid but it works, then it isn't stupid.
I'm not saying that the product in the OP's posting is a good idea. I will admit that I doubt that it works. Nevertheless, I'd like to see more data before spending $75 on that product.
I was re-zeroing a rifle the other day and sending some extra practice rounds downrange when I decided to point some electric fans at the rifle in an effort to cool the barrel. I didn't think it would work very fast but decided to try it anyway.
The fans belong to the club and are inside the rifle house for shooters to keep cool on hot days.
Anyway, after I pointed the fans at my rifle I noticed that the mirage from the hot rifle barrel had disappeared completely! This was obviously the result of air flow eliminating the heat waves and not a big reduction in metal temperature. [smacks self on forehead and wonders why that wasn't thought of before].
I could imagine the impression I would give someone seeing me shooting prone with two big electric fans blowing on my rifle. After all, I would never have electric fans with me in the field hunting so why would I use them at the rifle range.
Well, as I accidentally discovered, the mirage cause by barrel and suppressor heat disappeared. Note, I do use a suppressor wrap but the mirage is still there.
I usually like to zero all my rifles from a prone position on the bipod as I would shoot them in the field with 10 shot groups. I want to see the performance and any POI shift when the barrel heats up.
This gets difficult when mirage is factored in the shooting session. With the electric fans, the mirage is eliminated and I'm able to see what my rifles are capable of doing with hot barrels.
Next on my shopping or DIY list are mirage strips.
Back to barrel cooling. I've seen smarter men than me use the portable barrel cooling fans but articles that I've read with temperature readings taken at various intervals leave me wondering about the efficacy of these devices.
This leads me to another idea.
I have a gadzillion 12g CO2 cartridges for air guns and the CO2 tire inflator like the ones pictured below.
This entire subject of barrel cooling got me to thinking about using these CO2 tire inflators with flexible tubing to shoot a couple cold blasts of air inside the barrel to get it to cool after about 10-20 rounds.
The obvious concern is the blast of freezing air inside a hot barrel and what it does to cause any material fatigue.
I read on some other forums the same cause for concern. However, there was one person, who claimed to have some expertise in metallurgy, said it would not be a problem. I regret that I cannot find that link anywhere now.
Others have mentioned pouring cold water down a barrel. I've done that with a paper cartridge sharps rifle and a a 45-70 as well as other muzzle-loaders when I've shot a lot and need to reduce the fouling. Yet, I doubt that the temperature in a single shot blackpowder rifle would get as high as a centerfire semi-auto or bolt action rifle.
Still others have said they simply use a rag soaked with water and/or alcohol applied to the barrel to get it to cool.
So what is the consensus with the metallurgists in this group? Are there any advantages or risks with using CO2 or water to cool the barrel?
barrelcool.com 
