Looking for information on AR 15 Handguards......

[rramsey]

Good Morning, I am new to the world of AR-15's. I recently bought a DPMS Bull 20 flat top model with a stainless barrel. At a local gun show I was looking at a used metal round handguard with a knurled gripping surface on it. There were no cooling vents machined into it, just solid surface front to rear. My question is...On AR-15's built in North America are the handguards interchangable with the threads at the attaching points ? Does anyone recognize the handguard I described ? Thanks, Richard

 

[johnu]

I have a couple of ARs with the type of handguard you describe. They require a barrel nut that has male threads on the end away from the upper receiver - the handguard is screwed onto the barrel nut. Some have locking screws to keep them tight.

Vents in an aluminum handguard will help a some, but not as much as you might think. Why? Most of the heat transfer from the barrel will be via emittance (think hot barrel to colder atmosphere or surroundings) or via conduction (hot surface to a cold surface.)

John

 

[chuckbuster243]

Ar you asking if the threads on the receiver are the same? Or the different threads for free float tubes are the same? The receiver threads are the same on all ar15 uppers. The barrel nut outside threads that hold on the float tube are different. If you find two brands that match its by shear luck. Not sure what your question is. Matt

 

[jonbearman]

In almost all cases the answer is no. They all seem to use a proprietary thread ,meaning non standard.

 

[itchyTF]

FWIW, Krieger has their ARM-10A handguard. It is smooth with no cooling vents. The inside thread of the receiver nut is standard for the AR-15 upper threads but everything else is specific for this handguard. I have 2 of them and I like their design.

http://www.kriegerbarrels.com/Handguards-c1246-wp3395.htm

The picture doesn't show all the parts. Aside from the bipod stud there are 4 parts to the system.