Could someone explain what the difference is between single shield and double shield handguards?

I was looking at a few of my AR's and---for example---on one of them I can look down into the handguard cooling holes and see through the holes in the aluminum "inner" shield and can look right past it and see the gas tube and the top of the barrel. On a different one, I look down through the cooling holes and can only see the 'top' of a maroon or dark colored piece of aluminum----and can't see the top of either the gas tube or the barrel.

Is the first one a "single" heat shield and the second a "double" heat shield----or am I scr*w*d up on this?

Thanks for the education fellas!  CBR

Some single's will have the vents exposed, other may cover it.
If you plan on running more than two mags in succession, plan on getting either the double shielded or a railed system-then goes the debate on what cover's if any and/or a vertical grip.

Pop the current ones off and look at them, you should be able to see from that viewpoint.

Mark

If I understand this---is it correct to presume that the double shield HG's would have what would be considered to be two "layers" of aluminum inside of the poly handguards?

SIngle shield ones are your run-of-the-mill handguards for AR-15s, the Double shield ones are the ones you see on Military M-4s.



Here's a good example; the long ones on the top are AR-15 rifle lenght, single-shield handguards, while the ones on the bottom are the shorter M4 carbine, double-shield handguards. The reason for that is that since the M4 is a select fire weapon (SAFE-SEMI-BURST/AUTO), the heat generated during BURST or AUTO fire is significantly higher than that of a SEMI ONLY rifle, therefore double shielded handguards are neccesary. Another feature of the double-shielded handguards is that the shields are staggered, also note the location of the ventilation holes - they are on a 45 degree angle instead of on the top and bottom, so the heat doesn't esacape directly to the top, blurring your sight picture. Also, the double handsguards are staggered, so they lock together  ensuring not heat will leak through the sides of the handguards.

Just my .02 cents.

The issued M16 heatshields are single shield, just like your picture.

I understand!  Thanks guys!  CBR