Did Colt aquire their tooling in pics they look almost identical besides they are steel and have the AR18 mag catch on the right side man wish I could score one someday.  Also what happen to the tooling or was it lost or destroyed I heard Reed Knight purchased a bunch of Stoner 63 parts did he acquire some AR18 stuff too?

My GUESS is that after the military rejected the Colt 30 round continuous curve magazines, Colt sold the tooling to Armalite.  Armalite improved the magazines by making them out of steel instead of aluminum.  They also improved the feed reliability by replacing the sheet metal follower with a plastic follower. IMO the mags had to have been made on the same tooling because the bodies of both mags are so exactly alike. I also think that the vast majority of Vietnam photos showing “full curve” mags in theatre use, are actually Costa Mesa Armalite 30 round mags that were purchased by the soldiers or their parents.

So it would have been the other way around Colt sold to Armalite?

That is my best guess, and fits perfectly with the time line.

M16Indiana the info re the ArmaLite Costa Mesa CA 30rd parkerized steel mags all points to their intended mfg for the Howa AR-18 in 1967. I'd have to dig thru my files but I'm fairly confident ArmaLite got a patent for their design in 1967 and worked independently of Colt using their own tooling to produce the 30rd mags. I have magazine articles from 1969-1970 showing the ArmaLite 30rd mags that were to be sold with the Costa Mesa mfg AR-18/180 rifles. I'm only guessing re the ArmaLite mag tooling but it's possible that it was sold to Federal Ordinance who might of been former ArmaLite employees who made high quality aftermarket mags. When ArmaLite Costa Mesa CA closed for business they had depleted their stock of USA mfg magazines. Agree that a good number of photos showing 30rd mags in Vietnam may very well been the ArmaLite mags. I'll check my files and update re if it's a patent or drawing of the ArmaLite 30rd mag.

@kobren - Agreed, but the FAILED Colt 30 round full curve mags came out in 1966, and it seems like a pretty strong co-incidence that Armalite started producing their 30 round steel mag in 1967.  They WOULD have a patent for their mag even if using Colt tooling, because it was significantly different from the Colt mag (steel, instead of aluminum, totally different follower, no insertion hump, and the slot on the back side for the AR18/180 mag catch).  Besides, the curve of both mags is identical.

M16Indiana a lot of good points re the 30rd mags by Colt and Armalite that I won't dispute. Keep in mind that ArmaLite had their sites set on a large US military rifle contract and I doubt Colt would be selling ArmaLite any tooling to a competitor. Both companies were well aware of the US military request for a 30rd mag and both were in competition to design and produce a reliable mag at the same time 1966-67. Found the folder, technical drawing of assembly magazine 30rds AR-18, part number 2802, drawing dated Oct 3 '66, 30rd mag also in the revised AR-18 parts list I have. Big Rix has a far superior background to speak about ArmaLites capability re tooling and mfg of mags, rifles etc. Everything I have read indicates that ArmaLite had adequate resources in house and if needed to be farmed out there were a number of companies in Costa Mesa they could turn to.

My other question is once they decided on the GI 30rnd strait then curved mag is why they didnt mass produce them since most units in the 1970s and 1980s wouldnt see them at all unless a specialized unit I believe once the USMC adopted the A2 they were issued only 30rnd gi mags 20s went away wby the hell did it take so long?

The 70’s and 80’s is when they WERE mass produced.  Look at photos from the invasion of Granada (1983) and most of the magazines you see ARE 30 rounders.

Here is the info section of an original print of the magazine assembly. I'm not even sure if I'm allowed to share this but the dates might help with the discussion.

By the way I have never held a Colt 30 round Full Curve mag or compared them to a Costa Mesa 30 rounder.

Has anyone?

Got pics of a side by side?

@BigRix That date is 1966 which is when the military rejected Colt’s 30 round mag.  If Armalite did not get their tooling from Colt, they probably got hold of one of Colt’s mags and copied the shape (ie curve) because they appear to be identical when you hold them side by side. Below is a full curve Colt mag, a Costa Mesa 30 round mag, and a current USGI mag:

That's awesome I did notice the Costamesa seems just a hair straighter curve then the Colt either way I would love one of those big drool right now!