Rifle Length traditional hand guard

[strawf3]

A friend is putting together a AR10 using a standard hand guard using a traditional front cup and a delta ring in the rear. It seems that the hand guard is about .25" to long. Any ideas?

 

Gene

[Armed Eye Doc]

Welcome to the forum. 

Can you post some more details about the build and some pictures of the point of concern?  That would help a bunch to get some suggestions.

[blue109]

Is it an actual armalite AR10, or a 308AR rifle of a different manufacture? Not all guns use the same length gas tube. 

[Steve crawford]

Those hand guards seem to be a very tight fit.  Do you have a handguard installation tool?  I had a lot of trouble trying to change the hand guard on my AR-15.  It was easy after I got the handguard tool. My hands just were not strong enough to get the Delta ring down far enough to get the old handguard off and the new one on.  🥵🥵🥵

 

      Steve

[rpoL98]

On 4/6/2022 at 2:46 PM, strawf3 said:

A friend is putting together a AR10 using a standard hand guard using a traditional front cup and a delta ring in the rear. It seems that the hand guard is about .25" to long. Any ideas?

 

Gene

@strawf3

you need to use a barrel that uses the Armalite AR-10 gas tube length.  I suspect your friend's barrel is one that uses the standard AR-15 gas tube length.  for comparison, the AR-15 rifle gas tube is 15-1/8", the Armalite AR-10 rifle gas tube is 15-1/2".

the extra gas tube length means the gas port is that much further forward, and consequently the gas block and hand-guard cap is also that much further forward, enabling use of AR-15 drop-in handguards.

as an example, Faxon AR-308 barrels use the Armalite AR-10 gas port location, instead of adapting the AR-15 gas tube to their AR-308 barrels.

[rpoL98]

the AR-308 in the above picture uses a Faxon 16" Gunner barrel which is listed as "mid-length" gas system length, but in actuality uses the Armalite AR-10 carbine gas system length.

The Armalite AR-10 Carbine gas tube is about 3/8" longer than the AR-15 mid-length gas tube, enabling use of AR-15 mid-length drop-in handguards in an AR-10 platform.  this is all due to the taller barrel nut, evidenced by the bigger delta ring.

Edited April 27, 2022 by rpoL98
clarification