Google Free Pop Quiz - M16 Related

[Paul Gomez]

OK, here is a Google Free Pop Quiz...What that means is you cannot use the internet or any other reference resource to answer the question.

What are the differences between the M16A1 and M16A2 rifle as fielded by the US Army?

BTW, there are around a dozen.

They'll be some sort of prize for the person/s with the correct answers. I'll figure that one out.

Enjoy!

 

[SpeedRacer]

I could be completely wrong, but with no Googling this is what my brain is dumping out:

A2 - Added rear sight height adjustment, changed flash hider, added forward assist, changed barrel profile (thicker), different front sight post/adjustment tool, different buttstock (I believe the A2 is longer?)

 

[Paul Gomez]

You're getting there.

On the rear sight, there are three distinct changes.
The A1 had a forward assist. The A2 changed the shape.
On the buttstock, there are three or four changes, depending on how you count one of them.

The A2 flashhider omitted the bottom cut to prevent kicking up dust and crap when shooting prone. We borrowed that idea from the Israeli Galil flashhider.

The A2 front sight is flat topped and square faced whereas the A1 was a tapered point, almost cone like in profile.

The A2 barrel is thicker, in front of the sight tower, than the A1 barrel. That is not the only change.

 

[SpeedRacer]

Yeah I just Googled and smacked my forehead on about 3 or 4 things I shoulda known. I missed a couple of the biggies!

 

[Nolacopusmc]

forend?

 

[kengel2]

On the rear sight, there are three distinct changes.
The A1 had a forward assist. The A2 changed the shape.
On the buttstock, there are three or four changes, depending on how you count one of them.

The A2 flashhider omitted the bottom cut to prevent kicking up dust and crap when shooting prone. We borrowed that idea from the Israeli Galil flashhider.

The A2 front sight is flat topped and square faced whereas the A1 was a tapered point, almost cone like in profile.

The A2 barrel is thicker, in front of the sight tower, than the A1 barrel. That is not the only change.

Without looking, the rear A2 sight has a windage knob, elevation, and O2 peep.

The buttstock should be length and little door I believe.

I think the other barrel change is the twist, 1/7 instead of like 1/10 or something.

 

[Paul Gomez]

Without looking, the rear A2 sight has a windage knob, elevation, and O2 peep.

Yep, the A1 apertures were the same size but the center points were in different locations. The A2 has a large aperture, marked 0-2, and a small aperture for 3 and beyond. The center points are still in different locations.

The buttstock should be length and little door I believe.

Length, material of composition, & checkering of buttplate. A1s and A2s have checkering on the face of the storage compartment door on the butt. A1 buttplates were smooth surrounding the checkered door. M16 buttplates did not have a storage compartment at all. M16 buttstocks also had a pivoting rear sling swivel whereas both A1 and A2 stocks have a fixed rear swivel.

And NolaCop mentioned the foreend. The A2 design utilized a stronger material and consisted of two cylindrical halves. This did away with having to order/stock left side handguards and right side handguards, as was the case with the original triangular design.

 

[Quickdraw22]

Weren't the A1's completely flat on the right side (mag eject side) of the lower receiver??

Also, the older grips had a hole where you could put a metal loop to hold a sling. Never seen one with that hole actually utilized, but that's what I'd use it for

What do I win??!!

DAVE

 

[Richard in LA]

off the top of my head.
1. flashhider
2. barrel profile & twist? 1-12/1-7
3. front sight post
4. rear sight. elevation adjustment, and finger adjustable windage
5. handguards/retainer
6. pistol grip
7. length of buttstock
8. shell deflctor (Brunson bump)
9. FCG
10. slip ring/delta ring
11. reinforcements added around the receiver extension hoop and front pivot pin area
12. teardrop vs round FA button

 

[Paul Gomez]

Weren't the A1's completely flat on the right side (mag eject side) of the lower receiver??

Sort of. The reinforcements around the mag release, pivot pins and receiver extension had been implemented over the years prior to the M16A2 but were not a mandatory component of the design until the M16A2.

Also, the older grips had a hole where you could put a metal loop to hold a sling.

That and they did not have the finger shelf that was included as part of the A2 design.

So far, Richard's list has been the most complete.

Pangris,

As more than one woman in my life has informed me, I have more useless information that will never earn me money rattling around in my skull than ought to be allowed by international law. I was never sure if that was a complement or not.

 

[joshuades]

These may be wrong.

I think one of the barrel changes was to chrome line the barrel and chamber.

Also, I don't know if it was retrofitted after redesignation or was part of the A2, the FCG changed from full auto to three round burst.

 

[Paul Gomez]

I think one of the barrel changes was to chrome line the barrel and chamber.

That was an M16 to M16A1 change.

Also, I don't know if it was retrofitted after redesignation or was part of the A2, the FCG changed from full auto to three round burst.

Yes, the M16A2 was fielded with a 3 shot burst capability. The M16A3 went back to the Full Auto option and the M16A4 standardized the MilStd 1913/Picatenney Flat top config.

 

[Richard in LA]

Come on Paul, when you going to end this? I've been racking my brain trying to think of other "mandatory" changes, but cannot think of any, and I am resisting google in case I do.

 

[Paul Gomez]

Getting on the road to Bastrop. Will post this evening.

 

[Paul Gomez]

Starting from the rear of the gun and working forward:

A2 buttplate checkered. A1 trapdoor only checkered. M16 butt had no trapdoor.
A2 & A1 had fixed rear sling swivel. M16 had pivoting swivel
A2 stock is 5/8th inch longer. Requires spacer to fit on end of buffer tube & longer screw.
A2 plastic material much stronger than previous plastics.
Receiver Extension [buffer tube] interface reinforcements became standard on A2. They had been added to the lower receiver design prior to the A2 spec, so you will find some A1s with the reinforcements & some without.
Fire Control Group on the M16A2 has Safe -Semi-Burst. M16,M16A1 & M16A3 have Safe-Semi-Auto config.
A2 pistol grip is made of stronger plastic and has a finger ledge.
A2 Forward Assist is circular or 'bullseye' in shape. A1 is shaped like a golf club. M16 has none.
A2 rear sight assembly has adjustable knobs for deviation & elevation & has a large aperture & a small aperture. They do not have the same center point.
The A1 had two small apertures with different center points
A2 has integral brass deflector. M16 & M16A1 have none. I have seen an M16A1 or two with an integral brass deflector. This is sometimes referred to as an M18A1E1 or C7. The C7 was the initial M16 variant issued to the Canadian military. It was superceded relatively quickly by the C7A1 and, later, the C7A2.
On the A2, the dust cover spring was strengthened.
The reinforcements around the magazine release button were integrated into the design over the lifespan of the A1 but were not a mandated component of the weapon spec until the M16A2.
The slip ring which accommodates the rear of the handguards was changed to a tapered design on the A2 to aid in retracting it.
The A2 handguards are two interchangeable, semi-circular units. The A1 triangles necessitated a left & right piece.
The A2 barrel has 1:7 rifling. The A1 had 1:12. The M16 was initially supplied with 1:14. Additionally, the A2 barrel is thicker forward of the front sight base. Also, it is mounted with a crush washer in between the hider and the barrel as opposed to the peel washers used on the A1
The A2 uses a square, flat top front sight. The A1 used a round, almost cone like, front sight.
The A2 flash hider omits the bottom cut from the A1 design. The M16 initially had an open three prong design.

I think that's about it. Anyone come up with anything else, please post it. Feel free to google now and see if anything else pops up.

 

[Paul Gomez]

When did they replace the solid pin in the bolt with the cotter pin?

The solid stainless steel pin was part of Stoner's early design but, to the best of my knowledge, was never part of the military design.

Remember there were a lot of 'cost cutting' measures that McNamara & Co shoved down the military's throat concerning the M16, so even if the solid pin had been part of the design, they'd've probably nixed it.

Even today, you're looking at an $8 part versus a $2 part.

[I think it's worth it and have them in all of my bolt carrier groups, but that works out to less than $50.]