I have a carbine length AR. It has the round handguards and I want to change to triangular, like the early versions found on the rifles. I have found a set, but what I need is a set of the triangular guards that will use the "round" end cap. The reason is that mine has a 11.5" barrel with a 5" flash suppressor that is pinned/welded on, so I would like to be able to just swap hand guards. Does anyone know of a brand/set that utilizes the round end cap? I originally posted this on the Modern Military Firearms forum, but never even received a view, so thought I would post it here. Thanks in advance.

You might try contacting Aero in Washington, I have found them to be good to work with and answer questions on the AR platform.

Thanks!

Triangle carbine handguards are ultra-rare. I don't think anyone ever made any for round end caps. Early USGI triangle carbine handguards looked homemade.

airgun1:
I have found several reproduction sets for sale, but none of them show in detail what end cap shape they use. I found a set of the rifle length many years ago, that used the round end cap, but can not for the life of me remember who they were. Guess I will just have to spend some time on the telephone and see if I can't find them somewhere.

check your PM for pics.