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8/10/2012 5:15:59 PM EDT

Simple question, that I can not find the answer to.

What is the difference in a 16" M4 upper and a 16" M4A1 upper?


8/10/2012 5:18:16 PM EDT
[#1]
I think the A1 has a heavier profile barrel under the Handguards M4 feed ramps and a H buffer..

Google should give you specifics pretty quick
8/10/2012 5:18:46 PM EDT
[#2]
I always thought the only difference between the M4 and the M4A1 is that the M4A1 has the full-auto option while the M4 has the 3 round burst.  So I don't see how there is really a difference in the upper.
8/10/2012 5:50:04 PM EDT
[#3]
Quoted:
I always thought the only difference between the M4 and the M4A1 is that the M4A1 has the full-auto option while the M4 has the 3 round burst.  So I don't see how there is really a difference in the upper.


Exactly what has me confused.  Yet you will find some companies offering a M4 upper and a M4A1 upper.  

I can't tell the difference, and wondered if there actually is one.

Price usually doesn't seem to be a factor either.

Just curious.
8/10/2012 5:53:28 PM EDT
[#4]
Quoted:
I always thought the only difference between the M4 and the M4A1 is that the M4A1 has the full-auto option while the M4 has the 3 round burst.  So I don't see how there is really a difference in the upper.

I believe this to be correct. ^^^

Also there is no "16 inch M4" per se.
Civilian M4gerys use 16" barrels to get around SBR Tax Stamp issues.
(and they look odd with carbine gas, IMHO)
8/10/2012 5:57:05 PM EDT
[#5]
Quoted:

Simple question, that I can not find the answer to.

What is the difference in a 16" M4 upper and a 16" M4A1 upper?




M4 is capable of only a three round burst while the M4A1 is capable of full auto fire.
EDIT: Oops, misread your initial post, thought you meant the whole rifle....no more cleaning with Hoppes #9 and no ventilation for me..
8/10/2012 6:06:02 PM EDT
[#6]
Since 16” barrels come on civilian weapons there could be any number of differences at any given manufacturers discretion.
The official difference is the full auto selection, but it would appear that barrels that are heavier under the handguards and heavy buffers have shown up also.
No doubt it will all get sorted out sooner or later.
8/10/2012 6:27:30 PM EDT
[#7]
The A1 has the heavy ('SOCOM') barrel profile.

(The A1 lower is FA vice 3rnd burst.)
8/10/2012 6:55:02 PM EDT
[#8]
Early m4's has a2 uppers
8/10/2012 7:16:40 PM EDT
[#9]
Quoted:
The A1 has the heavy ('SOCOM') barrel profile.

(The A1 lower is FA vice 3rnd burst.)


This right here is your answer. The M4A1 has both features over the M4: full auto and heavier (under handguards) barrel.

8/13/2012 11:26:46 AM EDT
[#10]

Ok, thanks to all.

The answer is the barrel profile is different.

Just what I wanted to know.

Thanks

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