In Praise of the Colt 6720 (and 6520)

[Pachucko]

Here is my old war horse, brought out of retirement. Is the the correct lower for this upper? Ive switched and swapped so many times I wonder. So what says Colt Gods ? I thought this was a 6720?





PB

Yes, you’re correct. 6720 has the AR-15A4 Lightweight lower.


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[AndyLate]

Too bad they won't make a midlength. I'm just too cramped on a 7" handguard, especially after trying to fit a light.

But yes to the pencil barrel.

Ditto. I have a BCM midlength LW 16" w/FSB and I really appreciate the extra real estate.

Of course you can ditch the FSB + HG and run longer rail, but then we are moving away from the 6720/6520 configuration.

Am I the only one who has seen a Gov and LW barrel without handguards?

Andy

[SteyrAUG]

Ditto. I have a BCM midlength LW 16" w/FSB and I really appreciate the extra real estate.

Of course you can ditch the FSB + HG and run longer rail, but then we are moving away from the 6720/6520 configuration.






Andy

You can also run a bayo mounted light rail.

[Eurodriver]

Where can one find a Colt 6520?

[SteyrAUG]

Where can one find a Colt 6520?

Pretty sure it's discontinued. The 6720 was the flat top version of the same and now it looks like those are no longer available.

[Rogue556]

Where can one find a Colt 6520?

Gunbroker has them pretty regularly, but you pay Gunbroker prices of course. Other than that they pop up on occasion online as LEO trade ins from some of the venders that carry used stuff. I've heard of a few scoring them for a good price at pawn shops, but that's probably pure luck.

I've seen a few complete rifles pop up in the EE on TOS, as well as complete uppers and lowers. The AR6520's (post ban) aren't fetching the same prices as the R6520's (pre ban), but neither are as cheap as they once were. I'd guestimate the AR6520's in good shape are probably between $1,100-$1,500 and the R6520's are $1,500-$2,500. If you find a LEO trade in AR6520, you might pay closer to $800-$1000.

I got carried away and bought/built a few over the past year.

[SteyrAUG]

Given the difference between preban and postban 6520s being a M4 style stock vs. SP1 style and roll marks, I'd take that AR6520 any day.

I've got a pair of 2004 vintage LE rollmark rifles and I'm never letting them go. Also prefer the A2 sights vs. the A1s on the SP1 carbine.

[rifleman8]

There have been several iterations of the R6520 which have worn the "AR-15 A2 GOV'T CARBINE" roll mark from about the mid 80's to early 2000's

The first (sometimes referred to as "the green label") was a slab-side, shorty companion to the 20" Bbl. "AR-15 A2 GOV'T MODEL", also a slab-side. Not too many of these guns were made as Colt used up it's supply of SP1 forgings and moved forward with the A2 configuration semi-auto lowers.

Next came the "blue label" pre-bans with the new lower. This is one of my favorites, though I often question myself as to why, as it has been a major pain in my ass for three decades.

Most, if not all of the "blue labels" have large FCG pins and the annoying sear block. The sear block can be found held in place with one pin, or a pin on each side, and at least three different size pins were used over the years.

Most of these guns shipped with the .250" diameter screw type pivot pin, even though most (but not all) were machined for the push-pin pivot pin. A tell-tale sign of push-pin machining is a weep hole in the fence about 1.5" back from the pivot pin head. The ejection port cover must be closed to see this in a photo.

Blue label 6520's came in at least two shades of grey, I think what Ken of Specialized Armament would call "Colt medium grey" and "Colt dark grey"

I have probably handled no less than fifty of these over the years, and on all but one, fit of the upper to the lower was - well - crap, not to put too fine a point on it. The uppers - especially towards the rear are all cocked off to the left. This condition carried on into the post-ban versions of the 6520 as well, but seems to have gotten straightened out towards the end of 6520 production.

Most, if not all blue label 6520's uppers were machined for M4 feed ramps. Most (but not all) of these uppers have a small "4" stamped on the front of the carry handle.

All of the 6520's I have fired displayed exceptional accuracy. More so than (this might get me some flak) the several AR6721's I have had the pleasure to own and operate. Of course, as has been pointed out here, that pencil Bbl. is going to heat up pretty quick, and the "very good" accuracy of the HBAR will stay consistent for considerably longer strings of fire.

The pre-ban 6520's have lots of issues. Giant headache if you want better triggers or BCG's, ridiculous sight radius, silly receiver extension to name a few. Overall they are a large type pain in the ass, and I really like them. Guess I must have issues as well.