BarrelCool, A COOL Way To Cool Your Barrel

What could make a chamber flag cooler? By adding a small fan to it to blow ambient air down inside your barrel to cool it down. BarrelCool is exactly what it says. It cools your barrel while having the functionality of a chamber flag. This is that sort of device where you say “Now why didn’t I think of that?”

The BarrelCool chamber flag runs on three CR123 batteries and can run for 7-10 hours constantly.


The BarrelCool works in bolt action as well as AR type weapons.

Why would a shooter need this? According to BarrelCool some ranges require the use of a chamber flag during a cease fire. Some shooters will use this down time to cool their barrels using different methods such as running water on the barrel or pulling patches through the barrel. However some ranges do not like shooters to even be near a firearm let alone touch one during a cease fire. Usually because someone is down range changing or fixing a target.  With the BarrelCool chamber flag, you just insert it and turn it on then walk away.

The BarrelCool is only $34.99 on their website. Go to to check out more information.

Nicholas C

Co-Founder of KRISSTALK forums, an owner’s support group and all things KRISS Vector related. Nick found his passion through competitive shooting while living in NY. He participates in USPSA and 3Gun. He loves all things that shoots and flashlights. Really really bright flashlights.

Any questions please email him at


  • iksnilol

    CR123 batteries? Srsly?

    I’ll admit, it is a good idea. I kinda want to make my own from a computer fan.

    Also, never pour water on a hot gun (especially glowing hot), that ain’t good for the steel.

    • Nicholas C

      Shush you. Lol what about water cooled machine guns?

      • Zachary marrs

        There is a difference between throwing water on a hot barrel, and heating up a barrel encased in a water jacket

      • iksnilol

        Point is, the water is there before the heat.

        Gunning til the gun is cooking and then dunking it in water is a good way to screw up a perfectly good rifle.

        • randomswede

          Did you just feed a troll(ing), this must be part of a larger counter trolling scheme that I can’t fathom…

          • iksnilol

            We’re hitting maximum trolldrive.

            She’s falling apart cap’n, I d’nae know how long we can keep ‘er going.

          • MisterTheory

            you have to SHOUT THAT OUT!!!!!!!!!!!!!!!!!!

    • Mattie Dimes

      Why didn’t they put a solar panel on the top of it?

    • randomswede

      * A funnel with a tip that fits in your breach
      * A PC fan that fits the funnels big end
      * Some plastic pipe to hold the funnel in the breach securely
      * A battery holder for 8 D or C or AA or AAA batteries
      * A non momentary switch
      * Hot glue (and hot glue gun)
      * Bright yellow spray paint

      That’s a rainy afternoon and save for the funnel it’s probably all in that “this-WILL-come-in-handy-someday” bin.

      I guess I should add that you probably won’t be the prettiest princess at the range so if that’s a problem; $35 is the solution.

      • Jwedel1231

        Are you serious? It’s a simple product, reasonably priced, available now, and is actually useful if you want your barrel to cool down for any reason.

        Save your hate for something that deserves it.

        • randomswede

          No hate, just a DIY recipe in response to iksnilol ” I kinda want to make my own from a computer fan.”.
          I wouldn’t say “reasonably priced” though, I’d say niche priced which is perfectly fine for a niche product.

          Hate is the product of fear; I’m not afraid of a small yellow plastic device going up for sale.

      • And you won’t save much, even before you factor in the value of your time.

    • Martin M

      Agreed. From the picture I thought it’d take 4xAAs.

      Why not go super high tech and add a peltier you clip on the barrel to power the fan? Then you could charge more can claims like ‘eco friendly’, and ‘lower carbon footprint’. Besides, it’s not like they are in the business of selling batteries.

      I suppose it could be worse. They could make it rechargeable or give it some sort of proprietary power cell that requires an equally proprietary charging base.

      • JSmath

        Because battery cooling your barrel is never eco friendly, the way using a drier is never really eco friendly. Just being honest, I think you have a better idea, but they very likely chose the CR123 standard due to availability and costs benefits.

      • El Duderino

        Peltier? I was thinking a low profile Stirling engine. That would be awesome…maybe mess with accuracy just a tad with that piston moving around. 😉

        • Martin M

          That’s some full on steam punk there!

    • gunsandrockets

      Hmm… what about watering a cool barrel before firing? Or misting a warm barrel with a spray bottle?

    • Nope it certainly isn’t good for the barrel!

    • Badwolf

      I suggest ditch the battery compartment all together, make the unit smaller. Instead use a usb connector. You can hook it up to any power bank, the same used to charge your phone.

      • Now, THAT, I like! Cheaper in the long run than even CR123s!

  • TVOrZ6dw

    Because it doubles as a chamber flag, I can see this being useful to some people.
    For me, it’s jumping the shark.

  • Cymond

    At least it’s cheaper and more universal than Caldwell’s idea.

  • Ax

    Look at that graph. After a whopping 14 minutes of waiting, this product has produced a difference in temperature of 11 degrees Fahrenheit (which I think is about 6 degrees C).

    Also, note that the blue line starts out at 133 rather than 136, although that might just be that those first three degrees F of difference happened during the first 120 seconds.

    Is it really that much of a difference between a 121 F barrel and a 112 F barrel?

    Not worth it.

    • Sianmink

      It starts at 2 minutes, not 0. I’ll allow it.
      Still, for $30 and 3 CR123s, it doesn’t seem worth it. Couldn’t they at least run the thing on AAs?

      • Bryan Sumoba

        To get the same voltage output to run the fan and get the right airflow, you would need (6) AA or AAA batteries, which would make it difficult from a design standpoint to make it run as a chamber flag as well.

        • m-cameron

          Because we totally haven’t invented 9v batteries yet….

          • Bryan Sumoba

            A standard 9V battery has very little capacity as well. We were killing 9V batteries within 25-30 minutes. We get 7-10 hours with CR123A batteries.

        • jon spencer

          If a AA fan eats batteries, use Eneloops.
          Run them for a hour, replace with another and recharge.
          Just bought a kit with ten AA’s and six AAA’s with a charger for $27.
          Two thousand recharges are what they say is expected from the batteries. That’s equivalent to twenty thousand AA’s and twelve thousand AAA’s for under $30. Not counting the electricity, which might reach two dollars.

          • jon spencer

            Or a cordless vacuum with a Li. battery, put the hose on the bbl end and suck the heat out from the open action. With a good DeWalt or Makita you can get 6 to 8 hours run time on one battery. Bet those vacuum’s move much more air too.

      • Look at the battery life comparisons they keep posting.

        CR123s are *cheaper* than AA and 9v batteries at that point.

        • Sianmink

          how many hours do you need to run a bore fan though?

          • Based on their battery life comoarisons in this application, unless your AA batteries cost about 5% or less than your CR123s, you’ll still *save* money with CR123s. And if your unit ends up spending more time not being used than being used, you’ll save even more money – becauae you won’t lose any noticeable juice from storage losses with CR123s before you use the power actually doing stuff, whereas you *will* lose significant amounts of juice from your AA bunny batteries.

            This generally holds true for most CR123 versus AA (and most common batteries). If you actually track how often you have to replace batteries over a period of several years, the CR123 generally cost less overall, even though they are more expensive individually. Complaining that CR123s cost more than AAs is like complaining that a $2 2L bottle of soda “costs more” than a single $1.20 1L bottle.

  • So $35 for 11 degrees of cooling over 14 minutes not including paying for those over priced stupid CR123 batteries. Stupid gun accessory for people that have no clue but have too much money. Of course I’ve never been worried about over heating my bolt action barrel, I just can’t shoot one fast enough to do it and I have yet to meet any one else that with normal shooting can get one hot enough to do it either. If I were that paranoid about barrel heating from low rate of fire in a bolt action I would never shoot any of my machine guns.


      This doesn’t happen as often as it used to because surplus ammo has gotten so much more expensive, but…

      I have gotten my Mausers and Moist Nuggets cooking pretty hot from running them like Alex does in his videos. Range ceasefires where shooters are forbidden from touching their guns typically last 10 to 15 minutes as people go downrange.

      • Nashvone

        “Moist Nuggets” Best laugh of my day. And yes, I’ve gotten mine pretty toasty during a “group therapy” session.

      • jay

        I’ve burnt a few fingers after doing the “mad Minute” with my #4 Mk1. And been yelled at about no rapid fire. Of course the range masters eyes get big when they see what I’m shooting. I just can’t get my moisin to shoot as sweetly.

      • I’ve also gotten my Poison Maggot and No4 Mk1 too hot to comfortably touch, in aimed fire. Especially the People’s Ballistic Boar Spear (because the forearm is so thin), it isn’t hard to do with full power ammo.

  • Richard

    If it was cheaper, more effective, or both it would be more interesting.

  • LG

    In South Africa at safari style shooting matches, I have seen good sized fans mounted in the base of the gun racks to force cooling air through the breach and barrel. It worked a lot better than this possibly could.

    • Bigger fans, more air volume – I’m not surprised.

      However, could you chuck that unit in your pocket for a quick range trip?

      Everything is a trade-off…

  • TheNotoriousIUD

    I just keep all my bullets in the refrigerator.

  • Bryan Sumoba

    It is also made in the USA, which also accounts for a bit of the cost.

  • C. Her

    I was thinking that it should be AA or AAA powered but not sure if those would last long enough to surpass the CR123’s. Maybe an internal battery that is micro usb chargeable since most Android users have a micro usb chargers in their cars anyways?

    • Bryan Sumoba

      You got it right…AA or AAA or even 9V batteries do not have the capacity needed and would die within an hour or two. We are getting 7-10 hours of battery life in a BarrelCool, and a set is included with BarrelCool

  • 6.5x55Swedish

    Would be nice to have compressed air at the range

  • Aaron E

    An expensive chamber flag. Simply opening the action cools the barrel, and the degrees gained by this $35 contraption just doesn’t warrant the money IMO.

    • gunsandrockets

      Doubling the cooling rate ain’t bad.

    • JSmath

      For most people, I agree. For guys trying to be the next Jerry, I would definitely spend the $35, easy. Especially in the particular case they recognize, which absolutely is something I’ve seen at two ranges (one of them in Shittyfornia).

    • Anyone who does benchrest, or someone who run a lot of rounds at one time through the gun (if I owned a machinegun, I’d buy N+1 of these, where N= how many “air cooled” MGs I own).

  • gunsandrockets

    Not too expensive either. Sweet!

  • El Duderino

    This product literally blows.

    • El Duderino

      I should point out I was making a double entendre. I have no ill will toward the product. It actually seems…*cool*…to me!

      • Bryan Sumoba

        At a recent F-Class match, a shooter put (25) 7RSAUM rounds down his barrel in about 10-12 minutes. We could not touch the barrel (~150 degree F outside barrel temp if we had to guess). We placed BarrelCool in it and within 25-30 minutes, it was near ambient. We were feeling the air coming out of the muzzle and it felt like a mini blow dryer.

        • El Duderino

          Like I said, no ill will, just a low hanging joke there for the taking. If your product is the bee’s knee’s it’ll be all over the place pretty soon. And there will be a Chinese knockoff or 10 for $9.99 that take AAs by next year.

          • Bryan Sumoba

            Hopefully our patent (which is pending) will stop that 😉

          • Well watch the folks at SHOT who are always after designs to copy.

          • Patents have really never stopped overseas copycats before.

            C-Products made a couple very small changes to the Magpul AR-15 no-tilt follower, sold it as their own, and still managed to beat a patent infringement lawsuit.

          • iksnilol

            Are you 18? Cause you have that innocent and hopeful optimism going in that comment.

            The Chinese don’t care about patents. And if that somehow stops them, they’ll just make a small change or something to still be able to sell it. Though if you make the product good people will probably prefer yours.

      • Argh you’re on a roll__LOL!

      • iksnilol

        You might even say you are a fan of the product?

  • I think Nick said he knew people who did that not that he did it.

  • Badwolf

    Am I the only one who brings his refrigerator and generator to Uspsa and 3gun?

    What? If it’s good enough for my beer, then it’s good enough for my barrels.

  • Suppressed

    Being as Nick is an automotive enthusiast and has undoubtedly heard many a tale of warped rotors caused by thermal shock at the carwash or whatever, I’m going to guess he knows better than to put cool water on his own barrels.

    Granted, I could be wrong, but I’m giving him the benefit of the doubt on this one.

  • Dragonheart

    So you run air down the tube and it blows out a flame. How about a temperature sensor on the barrel to show how long it takes to make a real difference? Anyone priced the CR123 batteries lately?
    I don’t let my barrels get that hot, but if you really need to cool a barrel some highly filtered or better distilled water in a pump up sprayer with a rubber plug around the nozzle inserted into the chamber will push water down the barrel and cool the barrel. Water removes heat 25 times faster than air. Then, “VERY IMPORTANT “, run dry patches down the barrel to remove any residual water before firing; this also cleans out powder residue.

    • As I stated above, when looked at over the long term, I’ve found CR123s are actually cheaper than disposable batteries. Because batteries spend more time sitting around than running, and AAs go flat faster while sitting around. So, you spend less money replacing dead batteries when you use CR123s, generally.

      Plus, he stated above that they were having difficulty getting the voltage required.

  • Given how fast they go flat when not in use, I’ve found AA batteries are actually *more expensive* than CR123s, when you look at annual costs . 😉

  • The time to cool is really what attracts me.

    And I’d think NFA “stamp collectors” would be on this like a fat kid on the free dessert cart.