Hot handguard solutions

[Fuel Fire Desire]

For the sake of conversation.....



I have an AR pistol using a Magpul SL handguard. After a magazine of steady rate shooting, not even rapid fire, the handguard gets *very* warm. After two magazines, or after a mag dump, it’s too hot to handle. I’ve not had another AR act like this before, even with Magpul furniture (albeit MOE and not SL). The SL has the heat shield just like the MOE series has, but it’s much more slim.

Has anyone tried any methods to reduce felt temperature? Aside from wearing gloves (which I do with this gun now), has anyone tried doing something stupid like stuffing the air space under the handguard with crinkled aluminum foil, or wrapped the barrel under the hand guard in header wrap?

Not that I’d be compelled to actually go that far, but I’m just curious what others have done.




I have the same issue with another rifle using Magpul’s Zhukov stock.....but that has an aluminum chassis underneath the thin plastic that’s clamped right to the barrel.....acting like a heat sink. I ended up putting an AFG on that one, but I don’t think I’d do the same to this PDW.

[somecrazygreek]

Saw on a forum a while back a guy actually wrapped his barrel and gas system with a few layers of aluminum foil. Can't see it with the handguard on, makes a giant difference...or so he says. I haven't tried it personally, but there's a reason a lot of handguards come with heat shields on the inside, it's basically the same thing.

[10x25mm]

Is the temperature concentrated at one location - over the chamber or the gas block - or is it evenly distributed?

[Fuel Fire Desire]

Is the temperature concentrated at one location - over the chamber or the gas block - or is it evenly distributed?

It’s the entire length of the handguard excluding the area over the linear compensator. All around it.

I don’t have a picture of the heat shield, but it’s the same type used by other Magpul handguards. Which confuses me why this guy gets so unbearably hot...but my other carbines with Magpul furniture don’t.

I can’t say it’s specifically because of the SL handguard either. I never shot this pistol with the MOE handguard, and this is my first/ only AR pistol. So I don’t even know if the heat is inherent to the short barrel/ gas system itself.

EDIT: found some stock photos of the SL. It’s significantly more slim compared to the MOE, but the bottom and top are roughly the same distance from the bore axis.





My configuration with the SL






Same upper but with a MOE

[JDG]

My Saint don't heat up too bad, not like what your seeing... Plenty of air holes!

[10x25mm]

A thin fiberglass matte blanket without paper or aluminum backing should provide you with plenty of insulation ASTM C553 Types IV and higher are rated at temperatures of 850°F and higher. The lower number ASTM Types are only good to 450°F, which is a bit dicey. Thermal conductivity for all the fiberglass mattes is is about 0.25 BTU/(h⋅ft⋅°F) which is far lower than aluminum.

Wrap it in a 'C' pattern around the barrel - closed at the bottom and open at the top. The opening at the top will allow some heat to escape over time. Just keep in mind that cool down will take a lot longer and you really shouldn't fire more than 120 rounds before giving it a rest.

Fiberglass matte is readily available and cheap. The two downsides are discoloration of your barrel finish (which will burn off) and some tendency to retain moisture if you dunk your pistol or get rained on. Fiberglass holds about 5% moisture by weight at room temperature. That moisture will come off as steam if you run its temperature over the boiling temperature and steam can be unpleasant in and of itself.

[dirtmcgirt76239]

A thin fiberglass matte blanket without paper or aluminum backing should provide you with plenty of insulation ASTM C553 Types IV and higher are rated at temperatures of 850°F and higher. The lower number ASTM Types are only good to 450°F, which is a bit dicey. Thermal conductivity for all the fiberglass mattes is is about 0.25 BTU/(h⋅ft⋅°F) which is far lower than aluminum.

Wrap it in a 'C' pattern around the barrel - closed at the bottom and open at the top. The opening at the top will allow some heat to escape over time. Just keep in mind that cool down will take a lot longer and you really shouldn't fire more than 120 rounds before giving it a rest.

Fiberglass matte is readily available and cheap. The two downsides are discoloration of your barrel finish (which will burn off) and some tendency to retain moisture if you dunk your pistol or get rained on. Fiberglass holds about 5% moisture by weight at room temperature. That moisture will come off as steam if you run its temperature over the boiling temperature and steam can be unpleasant in and of itself.

what about a high temp automobile header wrap ?

https://www.summitracing.com/parts/d...RoC1aQQAvD_BwE

[10x25mm]

what about a high temp automobile header wrap ?

https://www.summitracing.com/parts/d...RoC1aQQAvD_BwE

Even better.

[Fuel Fire Desire]

That’s what I was kind of thinking, but didn’t know what kind of negatives to expect. This thing already takes a couple moons to cool off before I feel ol stuffing it back into its case. I don’t want to accidentally kill the barrel.

[UpNorthWOLF]

Is it because your muzzle device is inside the plastic?