M16A1 and A2/3

A little over a month ago I actually looked at the M16 at the top of the page and thought that there was something wrong with it in as much as the rear appeared to be that of an M16A1 and the front to be that of an M16A2/3.
I was going to comment on it but of course could not due to the lack of functionality of the CSP M16 page.
A couple of weeks ago I had occasion to spend some time in Small Arms at NSWC Crane. The rifles we disassembled (about 500) looked exactly like the one in the top of the page.
Namely the lowers were mostly manufactured by Colt and the uppers, of course had no stamping indicating manufacturer but I believe they too were of Colt manufacture. The uppers were of the M16A1 variety.
First the upper and lower were separated and placed in tri-walls.
We worked on the uppers only.
The first two guys would take a chamber brush on a hand drill and run it through the chamber then the same guy would run a bore brush through the barrel once. After doing that he dropped a metal rod type gauge through the barrel. If it went all the way through, the barrel was considered straight.
The next guy would use a throat erosion gauge to check for wear. If it passed, the upper assy was put on a cart and sent to the next station.
At this station the sailor removed the handguard and punched out the pin that held the gas tube in place and removed it with a special tool.
Next station was mine and I would put the upper receiver into a molded plastic device and secure it in a vice.
Then I would use one of those m16 tools you see all over the place and use it to remove the compensator.
Next, I would use a special tool not the above mentioned one but one with a longer handle to remove the nut that secures the barrel to the receiver. Once unscrewed I would remove the barrel, most I could just pull out, others I would bang on the front sight with a rubber mallot until loosened and then pull off the rest of the way. Then I would up-end the barrel with the muzzle on the table and remove the clip that held the nut spring and washer on the barrel and then slide them off and put them into bins on the table
Place the barrel on a cart and go on to the next one.
The parts were to be refinished and reassembled into M16A3 as the Navy does not use A2.
Almost all the barrels were marked FNMI 5.56 1/7 and the rifles were turn-ins from a SeaBee unit.
Like I said we did about 450 to 500 in two days. I believe I could do it in my sleep now.
The barrel gauging caused me to wonder about my "brand new" M16A3 I carried when last in Iraq. Was it really new or was it rebuilt and if rebuilt how worn was the barrel. It seemed to shoot accurately enough.
I think it was rebuilt.

Thanks for posting this. This is the type of information folks will be asking about in 10, 20 or 30 years down the pike. Imagine reading an account of a GM who had worked on rebuilding Lee Navy rifles after use in the Spanish-American War. Before something becomes history someone has to live it.

I watched a program on the reconditioning at Anniston Alabama of the M16s & M4s, and it was done in similar fashion. They looked like new when done.
Bruce

Some day they might let you take a bunch of them to the underground firing ranges and burn some ammo for the final test.

OFC