Colt 6720 - 6920 quality

[5.56 Bonded SP]

My new 6920 hasn't missed a beat.

I've shot tula, wolf, m193, m855, and handloads out of it.
About 1,000 rounds maybe more the past 2 months, and not a single malfunction. I've only had the gun since about September or October.


I pretty much only want to buy colts right now, and find them for the best deals possible.

My 6920 might have a lot of scrapes and cosmetic imperfections, but it gives me more peace of mind than any of my other rifles.
Something about those scuffed up colts just gives me a confident feeling.

I've owned enough lemon ARs from budget companies like S&W that I won't spend another cent on anything but Colts or other milspec tier 1 guns.

Does anyone else besides me have the issue with the mag well in the 6720 being tighter than the 6920?

I have issues with pmags in general not wanting to drop free after they get some use, the problem happens with 7 different guns I own.

Not trying to get into a debate, but I only buy lancers now after lots of not so great experiences with gi mags, and pmags. I've just come to accept that mags are disposable and don't last forever.

Ymmv

[grizzlyblake]

I hear you, I just more specifically think it's strange that two brand new Colt lowers can have different specs on the mag well size. I would've thought they would build them on the same machines and assembly line.

I can't fathom a reason they're intentionally different - just that it's sloppy tolerance allowances. I hope that doesn't go further than the mag well inner dimensions to other parts of the gun.

[Dienekes]

Had my 6720 since 2012. I wasn't happy with the exterior finish on the bolt carrier--it looked like it had been finished over old corrosion and frankly pretty grungy. Back then it was a $1200 rifle and I wasn't too happy about it. I mentioned it here and caught hell for being negative about the bestest of all rifles.

I'm now up to about 2300 plus rounds. The only thing I've done to the rifle is to install a Geissele G2S trigger and of course a good ($) optic. Zero issues, has always gone bang. I'm quite fond of it, should lay in another.

[MistWolf]

...I can't fathom a reason they're intentionally different...

They aren't. It's possible the mag catch is too tight. Back off the mag release button a half turn and test it. Do that a couple of times and see if it helps.

[grizzlyblake]

I'll give that a shot, but the mags all hang up about 50% of the way out. They release and then bind once they drop from the catch.

[Todd.K]

You are describing perfectly one of the occasional issues Magpul said the gen3 mags were a design improvement over gen2.

You can measure to see if it's in spec,
Use gen3 or GI mags,
Take a little sandpaper to your gen2 mags,
Sell the lower to a Colt collector and try a different lower

[5.56 Bonded SP]

You are describing perfectly one of the occasional issues Magpul said the gen3 mags were a design improvement over gen2.

You can measure to see if it's in spec,
Use gen3 or GI mags,
Take a little sandpaper to your gen2 mags,
Sell the lower to a Colt collector and try a different lower

Ya, i would be willing to bet money its the pmags that are out of spec, and that his lower is fine.

[squid8286]

I have two 6920s; one of which I bought about mid-2016, and the other in January, 2017. The earlier one will not drop Gen 2 P mags free. I haven't used it a whole lot yet. I suspect that with a little more use that will change.

[grizzlyblake]

You are describing perfectly one of the occasional issues Magpul said the gen3 mags were a design improvement over gen2.

You can measure to see if it's in spec,
Use gen3 or GI mags,
Take a little sandpaper to your gen2 mags,
Sell the lower to a Colt collector and try a different lower

The Gen3 20 rounder that came with the 6720 drops free just fine so I imagine getting some more Gen3s would be the solution to the issue.

What I have a hard time with is that two brand new Colts, fresh out of the wrappers, have different final specs on the mag well interior dimensions - whether it's milling, anodizing, etc. I don't know.

I don't see it as debatable because in the fresh 6920 the PMags are so loose they'll shoot themselves out if the rifle is held vertically and the mag release pushed. The exact same mags (brand new Gen2 PMags) have to be pulled with some force out of the 6720 when it's held perfectly parallel to the floor.

So let's assume the PMags are out of spec. Even then, why would a half dozen PMags be loose in one lower and overly tight in another? Logic only says that the dimensions of the lowers are in fact different. Remove the PMags from the equation and pretend it's a piece of wood. Tight in one lower, loose in another; points to differences in lower specs.

What I don't know is if Colt has a gradient of allowable measurements in these, and the 6920 measured out on the maximum spec while the 6720 measured out to the minimum, yet both passed QC. I'm just not familiar with the manufacturing.

[Sancho Panza]

Much easier to sell the PMags to PMag collectors.

If a mag won't drop free from every one of my ARs, it finds a new home.