Let me start by saying I am truly impressed with the knowledge of the individuals on these forums.  I'm facing a small dilema.  In anticipation of the AWB sunsetting I have pre-ordered a Colt A3 6721 from Impactguns.com.  I was also interested in the M4 6920, but chose the 6721 due to the 1:9 riflling twist.  I plan on eventually using this weapon on duty, so accuracy is highly important and this is why I felt the HBAR on the 6721 was better.  Could someon please provide me the differences of these two rifles and explain the positives and negatives of each.  Your honest opinion is greatly appreciated.

The weight and looks are really the only difference.  The 6920 will have the “M-4” profile barrel and it will be lighter.  It will also come with the “M-4” handguards and side sling swivel.  The accuracy will be the same.

Ray

Like I said on the other thread.  If you are looking for a safe queen, or a paper shooter, it doesn't matter.  If you are thinking about carrying it and / or doing work with it, the M4 variants tend to be easier to work with.  

I've carried both weapons on duty.  It really doesn't matter as they are both fine weapons.

Yeah the differences are fairly small.  6920 has the fat M4 handguards, M4 cuts in barrel, side sling swivel, and 1:7 twist.  I recently picked the 6721 over the 6920 mostly because the lower is marked "AR-15A3," which I find much more attractrive than "Colt's Law Enforcement Carbine." I ordered a M4 handguard and side sling swivel to replace once the rifle gets here next week.

Brian

only the 1/7 M4 barrels are chrome lined barrels and chambers......  I have a 6721 upper in 1/9 that is a good shooter, but no chrome barrel. The 6721 is a LITTLE heavier than the 6920 or 6520 versions, but if  you shoot the heavier rounds the 1/7 barrel is a little better, and the chrome plating makes it a little more durable.

Another vote for the 6920 - lighter, 1/7 twist for heavier bullets, and the ever so cool M4 profile .

i understand your delima, so i got both, & in a few more days i will have 3 more "Colt AR-15s"

Quoted: only the 1/7 M4 barrels are chrome lined barrels and chambers......  I have a 6721 upper in 1/9 that is a good shooter, but no chrome barrel.

WRONG!

I don't know why you keep posting this bull shit.  I'm not sure if thru some fluke you got at 6721 without Chrome lining, but the spec is chrome lining.  My 6721 has chrome lining.

Doesn't your barrel read "C MPC  NATO 1/9"?

That said, I suggest the 6721.  Unless you are humping this weapon for long hours or something, I always prefer the HBAR.  Also I like the longer life of the 1/9 twist.  I don't know if that is really measurable, but I feel warmer about the idea.

I am not TRYING to post bullshit.... just trying to accurately quote what I've read here from several different current Colt "experts" here online at AR15.com. Mine is definitlely a Colt and only says C MP(no 2nd C) 5.56 NATO 1/9 HBAR. I'm not an expert by any means, but just quoting what I've read right here. MY 6721 DOES NOT have a chrome bore/chamber, and if it did I would be posting otherwise. Maybe it's different for the LE6721 upper kits, but if you do some Searching here, I'm not the ONLY person that believes this "bullshit". I've been told MANY times from several sources, all the 1/7 Colt LE/Military barrels are chromed and the 1/9 barrels since the late '90s are NOT

like everyone else says as well.... Colt does different things with their parts.

PLEASE show us all where it says ALL 6721 1/9's are chromed

who pissed in your Wheaties??

6920 (M4)

HE's OUT OF PRISON!

Quoted: I am not TRYING to post bullshit.... just trying to accurately quote what I've read here from several different current Colt "experts" here online at AR15.com. Mine is definitlely a Colt and only says C MP(no 2nd C) 5.56 NATO 1/9 HBAR. I'm not an expert by any means, but just quoting what I've read right here. MY 6721 DOES NOT have a chrome bore/chamber, and if it did I would be posting otherwise. Maybe it's different for the LE6721 upper kits, but if you do some Searching here, I'm not the ONLY person that believes this "bullshit". I've been told MANY times from several sources, all the 1/7 Colt LE/Military barrels are chromed and the 1/9 barrels since the late '90s are NOT like everyone else says as well.... Colt does different things with their parts.

Ahh...  You're not talking bout the LE gun.  That's where we're differing here.  The LE guns are all chrome lined bores.

The guys here are asking about the LE guns that are coming available.  So they need to know what the barrel is on that model.  I wasn't aware that the civi didn't have chrome.  

Quoted:
I am not TRYING to post bullshit.... just trying to accurately quote what I've read here from several different current Colt "experts" here online at AR15.com. quote]

Watch what you read that has been posted by "experts" here.  There is a lot of quality info, but there is a lot of inflated opinion mixed in as well.

Quoted: 6920 (M4)

Hey!  What ever happened to you man?  I still never got the whole story.

I'm overdoing it. I bought a 6920 so I could switch uppers with my MT6400c. That way I have a cool M-4 upper and a cool M-4 marked lower!!

Or do like I did, and get the AR6721 lower, so it says "AR-15A3", and get a M4 upper to put on it.

Best of both worlds!

I've used my 6920 as a duty gun for about 6 years now with approx. 35,000 rds through it w/o a single malfunction.

If you want a tank of a weapon the 6920 is the way to go.