im confused, does the le6920 have the m4 profile (or is that the le6921)? heavy barrel, is that 6920 or 6921? from reading here i know both are chrome brl and chmbr and have the feed ramps.  im trying to decide what to get.                            BUT. you know what, i guess it doesnt really matter because i can only get the 6920.                      (6921 short barrel RIGHT??? not legal without paper work??)  any who, can someone tell want kind of barrel le6920 has, M4, heavy barrel or what.        i used to own a bushmaster 14.5 izzy. i had to sell because of unexpected financial needs. it was a great gun, real pretty, and work perfectly, i wanna try someting diffrent this time around.

Quoted: im confused, does the le6920 have the m4 profile (or is that the le6921)? heavy barrel, is that 6920 or 6921? from reading here i know both are chrome brl and chmbr and have the feed ramps.  im trying to decide what to get.                            BUT. you know what, i guess it doesnt really matter because i can only get the 6920.                      (6921 short barrel RIGHT??? not legal without paper work??)  any who, can someone tell want kind of barrel le6920 has, M4, heavy barrel or what.        i used to own a bushmaster 14.5 izzy. i had to sell because of unexpected financial needs. it was a great gun, real pretty, and work perfectly, i wanna try someting diffrent this time around.

The Colt 6920 has a lightweight barrel under the handguards. The 6920HB has a heavier
barrel, but costs substantially more. There are 6921 heavy barrels out there, but you would have
to either register it as in SBR or place a permanent F/S like the Phantom on the muzzle to comply with the NFA-required 16" minimum.

Be advised, Colts are not inexpensive.
Hope this helps.

The 6920 and the 6921 both have the M4 government profile (thin under the handguards) and grenade launcher notch.

6920 has 16" barrel and the 6921 has 14.5" but you could install a permanent FS like a Phantom to make it over 16", to avoid the SBR paperwork and tax.

The 6721 is the one with the HBAR barrel (heavy under the handguards) and no M203 grenade launcher notch in front of the FSB.

I love my LE6920.  I also have a Bushmaster M4A3.  I also have a Olyarms 9mm upper.