I have 21 AR's and have built many more than that, the largest
ID i have found and used is 1.75.
You can find 1.75 ID handguards from DanDef, YHM, DPMS, OLY, JP
and there is others.
You will need to do some mods to a long handguard and the gas block
if you want to use TP555's multi position blocks.
I used the JP Vtac because the vents lined up to my adjustable gas block.
