Barrel Cool

[RC20]

I was thinking a paintball tank at first, but thought about portability and thought the small cartridges(single range session) would work out pretty well. Not sure about how much pressure a scuba tank holds? or if there would be any integrity issues. (not a diver). But yeah the vortex cooler would be a similar premise.

Two sizes scuba tankes.

71 CF: Run 2450 psi as I recall.

80: 3000 psi (I had one, dive guy hated me, but I always had more air than everyone else.

It all gets reduced down to workable via the regulator.

There are adaptors for air rifles, that's a huge amount of pressure so you need right stuff.

Both air and CO because of the venture affect create cold (velocity increase, pressure decrease, temp drops) so they would cool better than straight air. Old carbs use to ice up because of that (and aircraft have a heat diverter to clear it out and or stop it)

[RC20]

I had heard of some folks running water through the bore on some pretty high dollar rifles when shooting in 105 F temps. When I lived in the desert years go I decided to try it since I couldn't shoot more than 2 shots in ten minutes without the barrel becoming too hot. Often it was too hot just sitting there in the sun after 1 shot or even ZERO shots.

It worked really well. Just run a few dry patches through when done and one lightly oiled and start shooting again. No adverse impact on Stainless tubes per bore scope inspection and accuracy / barrel life. I am still shooting some of those barrels a decade later. It cools significantly faster than water soaked rags on the outside. I usually do both the wet rags and the water down the tube. Make sure the steel is below 298 F before you do this. If water on the outside RAPIDLY sizzles away, you are likely on the upper edge or too hot to use water cooling. Let it air cool down below the boiling point inside the bore and then run water through it.

From Wikipedia:

Tempering quenched-steel at very low temperatures, between 66 and 148 °C (151 and 298 °F), will usually not have much effect other than a slight relief of some of the internal stresses. Tempering at higher temperatures, from 148 to 205 °C (298 to 401 °F), will produce a slight reduction in hardness, but will primarily relieve much of the internal stresses. Tempering in the range of 260 and 340 °C (500 and 644 °F) causes a decrease in ductility and an increase in brittleness, and is referred to as the "tempered martensite embrittlement" (TME) range.

Great supporting information