Very Early Costa Mesa AR-18 Pt 2

Lets look at the more interesting side of AR-18 serial number 057.

There are early features everywhere over here!

Of course like the other side you see no reinforcement at the front of the mag well. The most obvious difference is the lack of a dust cover. Early testing showed that there was just too much space for dirt and debris to get into the action. This was fixed during later production.

No curved charging handle on these early models, just like the AR-16 that proceeded it. To my understanding the spent cases would sometimes hit the charging handle and bounce back into the ejection port. To remedy this they changed the design to act somewhat like a shell deflector.

Reminds me a lot of the AR180B.

Other features that may not be so obvious, the reinforcing ribs in the upper extend all the way to the rear. They stop short on regular production models.

Finally we move onto the lower receiver. Compare the front of the trigger guard to the one in your gun safe.

(What do you mean you don’t have one?) (Go get one.) (You know you want to.)

On regular production models the front of the trigger guard serves double duty as a guide for the rear of the magazine. Not so on this example.

Let me know what you see that is different. There is at least one more thing that can be seen in the above photo. Can you spot it?

5 Replies to “Very Early Costa Mesa AR-18 Pt 2”

  1. Looks like it has the later stock latch as seen on all but the earliest rifles.

  2. Looks like the stock latch is the type used on all but the earliest rifles

  3. Wondering if the carrier and charging handle are the 3/8 diameter as used on the production guns or the earlier smaller diameter. The straight handle would not need the keyway in the carrier.
    The firing pin retrainer pin looks to be slotted not solid as seen on the production guns.
    Wonder if the gun shown has the early sight arpeture and spring like my 018.

  4. Serial 057 was mfg. 9-15-65 and transferred to Ft. Benning 9-17-65.
    Interesting huh?

  5. Although never met, its great to have Pete Fleis chime in. Wish I lived in MO or AZ so I could have toys.
    NY barely allows a pocket knife and we need to change our deadly Assault Rifles to “ not” assault rifles.

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