My apologies, but I brought this over here for some help with a quick decision:

If you had to choose between these two, and only these two, which route would you go and why?

upper A:
original slabside M16 upper
unknown round count
triangular handguards & everything

upper B:
T numbered flat top
postban DPMS 16" match barrel
approx. 500 rnds
YHM front flip up sight


p.s. it is to go on a Eagle Arms lower + this will be my first and only upper.  Probably remain that way until I graduate college (six classes from now)

Are you sure the upper is an M16 slabside/no FA upper, and NOT a colt SP1 upper?

The front takedown hole will be larger and it will not be cut for a sear, if it's an SP1 upper. If it's an original true non-FA upper, it will have the normal front pivot hole size, as well as having the sear cuts on the underside of the upper.

I know it doesn't answer your question, but it at least makes it easier to tell what it is exactily you're purchasing

No, this is an ex-Air Force upper.  Regular (small) hole front pin, etc.

My personal pros & cons are basically that the slabside is not chrome-lined, of course, but it does have a threaded barrel for muzzle device flexibility.  However, the flat top gives me optics flexibility and it has a chrome-lined barrel, but it's a post ban.  Augh!  What do I do?

Postban upper.
Save up the cash and have a gunsmith add an A2 flashhider at a later date.

Slightly used beats beat-to-hell any day of the week.

But aren't barrel threading costs stupendous?

can I get a bump?

Quoted: But aren't barrel threading costs stupendous?

im no expert but it shouldn't be that much, your average joe machinest should be able to do it.

Barrel threading is typically around $75.  Big deal.  You wont ever miss it.  If this is your first and only upper, get the one that is more versatile.  

You confuse me.... the DPMS match barrel IS chrome lined and the M16 barrel ISNT?  Are you sure.  Typically DPMS didnt do chrome lining until recently, and not really on "match barrels"  And pretty much all your M16 barrels were 1/12 twist chrome lined chamber and bore.... very rare to find one that wasnt.

Get the DPMS, heres why:

1.  target rifle tack driver that can outshoot you.
2.  Carbine length, more versatile, plenty accurate.
3.  More than likely, its a tighter twist rate, bigger range of ammo.
4.  Flat top, WAY more options.
5.  Shell deflectors and forward assist are a good thing.
6.  If an HBAR, it will have better heat handling characteristics than the govt barrel

The only cons are reduced fragmentation range from a 16" barrel, and I am sure thats really important to you.  

Quoted: But aren't barrel threading costs stupendous?

Check with a place like Kurt's Kustoms (in the idustry forum).  He charged me $85 to put on one of his A2 TakBrakes on my MT6731 upper.  That included the $45 for the cost of the brake.  An A2 flash hider can be had for $5-7.  My guess would be it would cost you about $50 total

Quoted: Barrel threading is typically around $75.  Big deal.  You wont ever miss it.  If this is your first and only upper, get the one that is more versatile.   You confuse me.... the DPMS match barrel IS chrome lined and the M16 barrel ISNT?  Are you sure.  Typically DPMS didnt do chrome lining until recently, and not really on "match barrels"  And pretty much all your M16 barrels were 1/12 twist chrome lined chamber and bore.... very rare to find one that wasnt. Get the DPMS, heres why: 1.  target rifle tack driver that can outshoot you. 2.  Carbine length, more versatile, plenty accurate. 3.  More than likely, its a tighter twist rate, bigger range of ammo. 4.  Flat top, WAY more options. 5.  Shell deflectors and forward assist are a good thing. 6.  If an HBAR, it will have better heat handling characteristics than the govt barrel The only cons are reduced fragmentation range from a 16" barrel, and I am sure thats really important to you.

Actually, early M16 uppers, barrels marked C MP C, meant chrome CHAMBER, but NOT bore, from the research I've done.  I agree on your points.

I believe you are right.  I got one of mine out of the closet.  Its a pristine Colt slabside M16 upper with birdcage FH... with a 20" skinny barrel.  It is marked only with "CMPC" on the *underside* of the barrel.  I always assumed this would be chrome lined on chamber and bore.

From doing a little reading, there were some early M16A1's that only had the chamber chrome lined, not the bore.  Bummer!  I pulled the birdcage off, and sure enough, I dont see any chrome on the muzzle, like I do on my bushmasters.  Damn.  I thought all these skinny barrels were pretty much chrome bore.

Quoted: My apologies, but I brought this over here for some help with a quick decision: If you had to choose between these two, and only these two, which route would you go and why? upper A: original slabside M16 upper unknown round count triangular handguards & everything upper B: T numbered flat top postban DPMS 16" match barrel approx. 500 rnds YHM front flip up sight p.s. it is to go on a Eagle Arms lower + this will be my first and only upper.  Probably remain that way until I graduate college (six classes from now)

Definately the new one...

1:12 is too slow a twist, IMHO... 1:9 is the slowest you should go...

Thanks for the advice, folks.  (although the poll results aren't extremely definitive)

Quoted: My apologies, but I brought this over here for some help with a quick decision: If you had to choose between these two, and only these two, which route would you go and why? upper A: original slabside M16 upper unknown round count triangular handguards & everything upper B: T numbered flat top postban DPMS 16" match barrel approx. 500 rnds YHM front flip up sight p.s. it is to go on a Eagle Arms lower + this will be my first and only upper.  Probably remain that way until I graduate college (six classes from now)

Wait a few days, until the AWB sunsets.
Then ask the question.

Well, I'm obviously going to wait to built it, but I can make purchases now all day long.