Local LGS has Colt branded 30 round G.I aluminum mags for 20- each. Want some quality aluminum, are they worth it? Just bought a new Colt carbine, figured it would be neat to have a few "Colt" mags.

no, it's not worth paying a premium for the COLT name on the floor plate. especially since COLT doesn't manufacturer them but is contracted out to make them by another M16 magazine manufacturer then  sticks the COLT name on the floor plate.

if you want a COLT mag to go with your COLT rifle then get a couple. but, as for them being better then other manufacturers M16 mags, no they aren't any better.

here is a dirty little secret, firearms manufacturers don't fiddle around making magazine. they all contract that menial job to magazine manufacturers. then charge the costumer a lot for it

SIG SAUER and others ie. BROWNING  contracts MEC-GAR to make their mags. the exact same mag ie. that SIG wants 40-some bucks for  you can buy the MEC-GAR one for 20- some bucks. both the same mags, one packaged in SIG package the other in a MEC-GAR  package.

I would say pick up some of Brownell's private branded mags and change out the bottom plate for one that is stamped Colt, I just saw an auction that a guy was selling 20 Colt branded bottom plates for $15 bucks shipped, the Brownell and even D&H are pretty much the same thing.

I saw a ton of these at Clyde Armory, was tempted to get ONE just because. The green followers these have any good?

Its just a name. Funny if you set a box out at a gun show first thing people do is look at the floorplate or fingerfk the follower.
Everytime.

The followers worked great until people made up the tilt myth.
I clocked right at 25k rounds through an M16 before hearing about tilt. Worked every time

Go buy Sure feeds for $12 at 44mag.com

Anti tilt followers are not a myth, but as pointed out many times, they are not required in a straight magazine, they have been proven successful in the curved 30 rounders and most often that is what the newer magazines have.

Just to expand on this, Colt, Okay, and NHMTG magazine are all made in the same factory. They all wear the same cage code, 33710. If you place them side by side, you can even see that the welds match up on the spine of the magazines (different from Center Industroes, for example). My understanding is that Okay magazines were originally only for government contracts, and NHMTG-branded mags were for commercial sales, but of course they also made Colt-stamped mags. If you see any of these brands for sale at gun shows, it's common to see the Colt mags marked at a higher price on the same table simply because of the name. I've bought Colt mags when they were reasonably priced ($8 - $10), but don't be fooled by someone telling you the Colts are better, or even different, for any reason.

For whatever reason, they have recently discontinued the NHMTG-marked mags and are now selling the Okay-branded mags commercially under the "catchy" Surefeed name.

The military mint green follower is usually fine, but I like installing the Magpul follower just for a little added reliability.

You have a Colt rifle, You paid extra for it, so I would get a mag or two that also say Colt on them.

Colts have been shipping with Pmags for at least three years.  

That's the best Colt mag I've seen.

Not just the floor plate.

I have some old Colt magazines with the Colt part number 62667 stamped in the mag and the Colt part number 62665A on the follower.  The floorplate  shows the pony and says Colt AR-15  They do not have the Okay stamp inside the magazine.  These were made by Colt in the late 1960's??  Does anyone have any info on these and are they worth any premium to a collector?

Abject fraud...

OKAY magazines are the gold standard. Now that you can buy them under the Surefeed name for $12, there's no reason to buy any other magazine. Brownell's and D&H magazines are second class quality. If OKAY's at this price were available in 2007, PMAG's wouldn't exist today.

I have seen it a lot at the gunshows I have attended, in fact there were a couple of vendors at the SHOT a couple of years ago that were taking orders for bottom plates for the retro crowd.

I have not done it, I have some Colt branded mags and I don't use them.

If someone wants to change out the plates and is not trying to sell them as Colt, then there is no fraud, just like a lot of guys build retro rifles and send to Braceman to have the lower reprofiled and marked Colt.

I have a couple of dozen Colt mags from the Vietnam era to today. But I sure as hell won't pay extra for them. If I bought new mags, they would be the D&H 30 rounders from PSA for $6.99 apiece. Dirt cheap, and they work.

A long time ago I traded a guy for a bunch of Colt 20 rounders.
The base plates are marked "Colt AR-15 .223" and address.
They have aluminum followers.

All the USGI 20s, including Colt, have aluminum followers.

Some Colt Commercial 20s had black plastic followers.