Jimmy Rigged AR15 Barrel Heat Sink

[Asavage270]

Hello all, I am looking for input on potential home made heat sink designs for AR barrels.
I am beginning building a upper that will get abused with high round count / heavy firing schedule and have been toying with the idea of barrel heat sinks.
I am aware of the JP enterprise heat sink and am a fan of the design and also aware of its shortcomings; for this upper build accuracy is not paramount, cooling is prioritized.

Unfortunately I am going to be using a heavy chrome lined barrel that has a diameter of larger than .750 near the throat so the JP will not work. So I have turned to custom design.
Does anyone have any ideas that they have dreamed up?

I am going to be using a 1" diameter barrel and up to a 1.8" inside diameter hand guard.

I have considered scraping the whole idea and just using cheap chrome lined barrels that are disposable but figured i would pick the minds of some fellow gun nerds first.



Here's a couple links to potential ideas

EveryMarket

everymarket.com

^wrap around coil style heat sink (lacks barrel adhesion, and can't find in aluminum)

Round Heatsink for LED - Diameter ⌀45mm / ⌀1.77"

SKU 2004ASL Type Round LED Heatsink Material Aluminum 6063-T5 Surface Non-Anodized (Mill Finish) Diameter (Width) ⌀45mm / ⌀1.77'' All of our Heatsink Extrusions are stocked as full length (78'' to 118'' depending on the extrusion). We cut to your specified piece length (inch/mm) per order. We...

heatsinkonline.com

^ solid heat sink (would need to be lathed out to fit 1" barrel profile, along with some sort of clamping design)

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[ScottInPDX]

Hmm, an interesting engineering problem...

How much of a concern is weight? Will you be shooting from a bench or running around with this? And how long is the barrel?

Any reason you don't want to go with a fluted barrel instead?

 

[bcp]

Water cooled.

https://www.google.com/search?sca_esv=579833118&q=water-cooled+ar-15&udm=2&source=univ

Bruce

 

[powermad]

Barrels can be swapped out pretty easy.

If you think you may be shooting barrels out I would look at SOLGW, buy the barrel once, shoot it out and they will get you another.

 

[NobullSKS]

Water cooled.

https://www.google.com/search?sca_esv=579833118&q=water-cooled+ar-15&udm=2&source=univ

Bruce

Make the circuit long enough to warm an MRE

 

[arakboss]

Hose clamp a few of these to barrel and you'll be good to go.

0.827'' (21mm) Wide Heatsink (821AS)

0.827'' (21mm) Wide Heatsink (821AS)

heatsinkonline.com

 

[Asavage270]

Hmm, an interesting engineering problem...

How much of a concern is weight? Will you be shooting from a bench or running around with this? And how long is the barrel?

Any reason you don't want to go with a fluted barrel instead?

Not terribly concerned with weight, but I dont want to strap more than about 1-2lbs on if possible.

I'll be running a 20" barrel, and would like it light enough to be able to lug around.

Fluted barrels offer a better heat dissipation than round barrels but not significantly so.
They would also reduce the barrel surface area in contact with any form of heat sink applied to it; there by reducing the effects of the fluting and the heat sink.

 

[Asavage270]

Water cooled.

https://www.google.com/search?sca_esv=579833118&q=water-cooled+ar-15&udm=2&source=univ

Bruce

While an impressive design I'm trying to keep the weapon system man portable

 

[bcp]

For use between shooting sessions, put a fan on the bottom of a magazine housing

Bruce

 

[Asavage270]

For use between shooting sessions, put a fan on the bottom of a magazine housing

Bruce

Yeah I saw these and they do work well but I was hoping to find an active (during use) cooling design. I even thought about 3d printing in high temp resin a picatiny mount for a small fan that stays pointed at the heat sink
Would be goofy as all hell but would work

 

[Asavage270]

Amazon.com

I have one of these mini air pumps that I use for back packing and it runs around 2 hours on a charge and it has significant air output. Now I just need a pic rail mount lol

 

[TTSX]

Move to Wyoming for the winter. No bolt ons necessary, just a coooool barrel

 

[Caveman Jim]

Get one of these and save some $$$.

Made of heat resistant and flame resistant split leather, all sewed by Kevlar stitching, provide extremely high heat protection up to 932°F(500℃).

AP-1166 Heat Resistant Welding Gloves

Made of heat resistant and flame resistant split leather, all sewed by Kevlar stitching, provide extremely high heat protection up to 932°F(500℃). Double Reinforced Leather Padding on key positions such as Fingers, Palms, Elbow& Backs, provide extreme heat resistant protection and increase...

yeswelder.com

 

[CamoDeafie]

0.936" Bull barrel blank, get a machine shop to turn fins like this Japanese machine gun, make sure smallest diameter no smaller than 0.625" diameter.

 

[Flopsweat]

Hose clamp a few of these to barrel and you'll be good to go.

0.827'' (21mm) Wide Heatsink (821AS)

0.827'' (21mm) Wide Heatsink (821AS)

heatsinkonline.com

Get a bull barrel and machine it square, then attach flat heatsinks like this to it.

 

[CamoDeafie]

Get a bull barrel and machine it square, then attach flat heatsinks like this to it.

I think if one could machine it square, one could slot it/flute it deep enough? Or fin it (kinda like cutting deep ACME threads)..

 

[Flopsweat]

I think if one could machine it square, one could slot it/flute it deep enough? Or fin it (kinda like cutting deep ACME threads)..

Milling it flat sounds a lot less complicated. The heatsinks are only $7 each. It's not worth the effort, and you get more surface area with the store bought heatsinks.

 

[CamoDeafie]

Milling it flat sounds a lot less complicated. The heatsinks are only $7 each. It's not worth the effort, and you get more surface area with the store bought heatsinks.

I dunno. Turning grooves 0.125" deep from a 0.936 barrel can be done pretty quickly on a good CNC lathe. And this would have the smallest outside diameter of 0.686" which is still larger than pencil profile 0.625. And that's just for the straight parts where you can go down that deep. It'll look a bit wonky but doable. Could even turn the gas block portion down to 0.750 and then do govt profile from gas block to muzzle and cover the fins with a handguard...

Edit the $7 heatsinks are probably extruded aluminum and might melt.

 

[arakboss]

Get a bull barrel and machine it square, then attach flat heatsinks like this to it.

Why settle for square. Octagon Barrels were a thing. Eight heatsinks are twice as good as four.

 

[ferret427]

Just an odd thought, but instead of squaring the barrel, just go with a straight profile. You could then spec the sink clamping surface to match the barrel diameter.

Also....wonder if it would benefit from using an interface like Cryo Paste or other thermal paste/grease (used for heat transfer from a computer CPU's lid to its heatsink). The tolerances between the sink and the barrel would have to be fairly tight.