Closest to mil-spec?

[mljdeckard]

I have recently had a change of plans.

I thought I was very done with the army, but I was extended a very lucrative offer to go back into the Utah National Guard. I WAS going to build two ARs, one in M-4 configuration, and one for varminting. But NOW, I find myself in the position where I don't want to spoil myself to an after-market trigger and sights, etc, and THEN try to qualify with a rifle made by the cheapest bidder.

Assuming my issue weapon will be an older M-16 A2, no frills, what is the very closest AR I could buy or build to this?

 

[jagdpanzer347]

I would say either Colt or Bushmaster.

-jagd

 

[DMK]

The key to a copy of that weapon will be in the barrel. You don't want an HBAR. Most of the manufacturers will try to sell you one.

I'd buy a regular A2 stocked lower made by Colt, RRA, Bushmaster, Armalite or even DPMS (or build one from a bare receiver). Then order the proper upper from Bushmaster or CMMG.

What you want is a 20" Government profile with a chrome lined barrel and chamber like this one with a 1/9 twist from Bushmaster(shown below). A 1/9 twist would be easiest to get and some may argueis better for general purpose use, but a 1/7 twist is what the real M-16A2 has. You can call Bushmaster and they can build you the upper with that 1/9 twist barrel no problem, it's a stock item. Once in a while, they even make a run of those barrels with 1/7 twist. You may get lucky and get one now, or you may get put on a list for 12 months until the next production run.

CMMG also sells an A2 Govt. profile upper but with the proper 1/7 twist right here It's the CMMG 20” Gov’t Upper, order it with the A2 upper, no feed ramp, round foreward assist and standard front sight base. (or you could build an M16A4 copy by ordering the A3 upper with the F Marked sight base which is slighty taller to line up better with the detachable carry handle/rear sight).

Bushmaster uses 4150 steel just like Colt and FN use on the military contract rifles. I'm not sure if CMMG does. But honestly, with chrome lining and semi-auto fire, you don't really need the slightly harder steel. 99% of the rifles out there use 4140 in their barrels.

The M16A2 copy will be a nice rifle. A good light weight, general purpose AR. I built one (pic here) with the Bushmaster 1/9 twist barrel during the AWB years (no flash hider or bayo lug unfortunately). It's my second favorite rifle only to my pristine Garand. I love the simplicity and balance of it. Mine's very accurate. I'm not missing the heavy HBAR at all.

 

[PvtPyle]

Buy a Stag. If you buy a Colt, it may as well be a Stag. If you buy an RRA, it may as well be a Stag. They do a lot of other peoples parts.

There are only a few actual manufacturers of parts, the rest just assemble them.

 

[ny32182]

So the military M16A4 (20" flat top) uses an F marked FSB?

 

[PvtPyle]

I dont know, we use M4's for everything. Any Marines know?

 

[ocabj]

Get any milspec lower and basic lower parts kit (ie: Stag lower with Stag LPK). Standard A2 stock. Then get an A2 upper with carry handle and a 20", 1 in 7" chrome lined barrel and a 5.56NATO chamber. CMMG has a good complete one.

New 20" gov’t upper. This upper comes with full handguards and is complete with bolt, carrier and charging handle. CMMG semi auto bolt carriers have the shrouded firing pin to protect against hammer wear. Upper receivers are "T" marked and include extended feed ramp cuts. Features include gov’t contour barrel, chrome lined 5.56mm chamber and bore, 1/7 twist, parkerizing under “F” marked forged front sight base and magnetic particle testing on every barrel. When ordering with optional gas block, barrels will not be drilled for taper pins. Barrel is marked CMMG MPC 5.56 NATO 1/7.

NOTE: Picture shows A3 version. You can get it in A2.

 

[Don't Tread On Me]

I disagree. I've found the CMT (same as Stag) LPK to be rough and no different in quality than some of the LPK's found in kits.

I think Bushmaster's is better, but they have that cheesy trigger guard and I've heard stories of some low quality parts being sourced into their LPK's in the past, but I can't confirm this myself.

The LPK in my Colt is by far the best. Not saying that because it's a Colt or I own it. That's just what I see with my eyes and feel with my hands. Parts are made much more cleanly. The also exibit less wear compared to other parts that have seen the same round count. I know people say that CMT makes the parts for Colt. This may be true. But I've read others claim Colt hand selects the best parts. You can see the difference, at least in my experience. There must be some truth to this.

There's a lot of experieced people in this thread, but I have to disagree. I do not believe RRA or Bushmaster to be the equal of Colt. I find Colt to be better in a number of areas, and the Colt is by far, the absolute closest in quality of manufacture to the military rifles (which are better than their commercial cousins).


By the way, your rifle in the service might have been made by the lowest bidder - but it was still made to the government's specification. Which is, you might want to know, a whole heck of a lot more stringent and demanding than what RRA or Bushmaster holds their rifles to. That's a fact.

 

[ny32182]

If the guy wants to get as close as possible to the FN mil-spec, he will get either a CMMG or Bravo Company upper... both are much closer to milspec than anything in the Colt civilian lineup.

 

[HankB]

Unless you go to the graymarket "LEO only" rifles - for which you'll pay a premium - today's Colts will be AWB-compliant, and also have things like a block in the lower and nonstandard pins, along with (on some models) a plastic recoil buffer. And if by chance you DO need warranty work done, good luck having Colt do it. I'd avoid them for that alone, aside from their unsavory politics.

Still, having said that, the Colt LEO-only rifles I've seen DO seem to work well.

But then, so do Armalite, Bushmaster, RRA, etc.

Bushmaster is a very good alternative, and I've heard good things about S&W's new rifles, but being new, they seem to command a premium.

If you're using GI ammo of any type, you won't be able to tell the difference between a 1/9 and a 1/7 twist.

 

[DMK]

I disagree. I've found the CMT (same as Stag) LPK to be rough and no different in quality than some of the LPK's found in kits.

I think Bushmaster's is better, but they have that cheesy trigger guard and I've heard stories of some low quality parts being sourced into their LPK's in the past, but I can't confirm this myself.

The LPK in my Colt is by far the best. Not saying that because it's a Colt or I own it. That's just what I see with my eyes and feel with my hands. Parts are made much more cleanly. The also exibit less wear compared to other parts that have seen the same round count. I know people say that CMT makes the parts for Colt. This may be true. But I've read others claim Colt hand selects the best parts. You can see the difference, at least in my experience. There must be some truth to this.

I use DPMS LPKs and they all work just fine. I'm a perfectionist and have never seen any flaws in finish or function with the parts. However, on all my lowers (I've built four so far on two DPMS and two Eagle Arms recievers) I've swapped the trigger parts for RRA NM triggers. These triggers are, very, very sweet. They break like the proverbial glass rod with no creep at all.

Colt probably does make the best bolts. However, I've purchased RRA bolts on all my builds and have found zero problems with them and I like the more substantial carriers on them.

 

[LoadedDrum]

I have the CMMG 20" A2 Government. If you get it, you will not be dissappointed. Bravo Company's version is also a good way to go.

 

[ny32182]

So the military M16A4 (20" flat top) uses an F marked FSB?

Please, if *anyone* knows the answer to this, I would much appreciate it. I thought that the F marked base was specifically for some sort of sighting correction on carbines, but don't really know for sure.

Also, do current production 20" M16's use the extended "M4" feed ramps?

 

[ocabj]

I own Colts so I don't doubt quality. But the key point here is "Milspec". Civilian market Colts are not Milspec as others have pointed out. The Stag lower and parts plus the CMMG complete Government upper will give the original poster a Milspec M16A2 clone (short of select fire with three shot burst).

As far as the M4 feed ramp question, no, military M16s don't have M4 feed ramps. Hence, the nomenclature, "M4 feed ramps".

 

[DMK]

Please, if *anyone* knows the answer to this, I would much appreciate it. I thought that the F marked base was specifically for some sort of sighting correction on carbines, but don't really know for sure.

It's my understanding that M16A4s do have F marked front sight bases to correct for a taller carry handle. Now, I've never seen a real M16A4, so my info is second hand. I've just done a lot of research on folks building clones of them and folk posting detailed pics of them on AR15.com.

 

[ny32182]

Thanks. I intend to put together a clone myself. Might make one exception and add the M4 feed ramps, even though it seems they are not in use on M16s at this time.

 

[Lebben-B]

Yes, the M16A4 has the "F" marked FSB.

Mike

 

[Phantom Warrior]

Not to be contrarian here, but I'll just throw in my experience. I'm an Active Army Joe. I work in a 3 shop, but I also work part time in the arms room (don't ask).

What we had before we got our brand new shipment of M-4s was worn, well-used M16A4s and some even more well-used A2s. The key word here being WELL-USED.

Everyone is arguing about the minute differences between this and that upper. Frankly, if you buy a basic AR with a 20" upper you are pretty much going to be there. Avoid match triggers, free float handguard tubes, and other custom modifications and I doubt you'll be able to tell the difference. I suppose you could drag it through the gravel a few times to scuff up the finish...

Also, if you are really interested in getting the closest copy possible, you might want to talk to someone in your guard unit. In my admittedly limited experience, I've found that a lot of Army units are going to A4s with a quad rail handguard to faciliate the attachment of sights and gear to the weapon over the basic A2 with plastic handguards. Just a thought.

 

[MisterPX]

My FN A2 doesn't have M4 feedramps. Stick with a well regarded manufacturer, get a 1/7 barrel, and you'll be fine.

 

[ny32182]

Well, the point of my next 20" rifle is that it be at, or as close as possible, to a semi-auto version of the M16A4 spec. For historical accuracy and lighter weight of the gov profile barrel more than anything else, really.

I agree that a 20" rifle from any of the major makes should function great. My current Bushy 20" HBAR certainly does, though I might have to sell it soon to fund other projects.

 

[DMK]

Frankly, if you buy a basic AR with a 20" upper you are pretty much going to be there.

Well, that's just the thing. Although the situation on the market is getting better, most manufacturers want to sell you an HBAR. Only a few companies even make a Government profile barrel. I have two Govt. profile 20 inch rifles (an Bushmaster barreled A2 and a Bravo barreled A4). They are noticably lighter and feel much handier than my 16" HBAR. While a 20" HBAR may look like an M16A2 with the handguards on, it's not a minute difference.

Now my Govt. profile 16" midlengths, those are just heaven with a pistol grip, but that's for another thread.

 

[mljdeckard]

Thanks guys, this is very helpful. While I want to build a bone stock A2, I'll still build a M-4 and something in the same vein as a Bushmaster Varminter Special for coyotes.

 

[Aguila Blanca]

Is it correct that the M16A2 has/had a 1:7 barrel twist? I was in back before there was an M16A-anything ( I was in 'Nam when we transitioned from the M14 to the M16), but I didn't think the 1:7 twist barrels came along until much later than the A2 was phased out.

In fact, it's been my understanding that a lot of NG units still have 1:12 barrels and can't use the 62gr M855 ammo because the slow twist of their barrels renders the ammo useless beyond about 75 meters. The older M16s with the slow twist barrels were designed to shoot 55gr ammo, and that's what they need.

A 1:9 barrel will shoot both, but isn't fast enough to stabilize the newer 72gr, 75gr and 77gr bullets that some of the elite units are playing with in the sandbox.

 

[Lebben-B]

The M16A2 has a 1:7 twist barrel. This twist was selected IOT stabilize the M856 tracer round, which is substantially longer than the M855 or M193.

Mike

 

[DMK]

Is it correct that the M16A2 has/had a 1:7 barrel twist? I was in back before there was an M16A-anything ( I was in 'Nam when we transitioned from the M14 to the M16), but I didn't think the 1:7 twist barrels came along until much later than the A2 was phased out.

M16s, M16E1s, M16A1s, XM177 carbines and early(thin barrel) USAF GAU-5 carbines all had 1/12 twists. The thin barrel is the give away.

M16A2s, M16A3s(if these even exist), M16A4s, M4 carbines, and USAF GUU-5P(M4 barrelled) carbines all have 1/7 twist. These all have heavier barrels with machined profile areas under the handguards. The M4 barrel has a thick groove cut in front of the front sight. The M4A1 has that groove, plus a cutout in it's heavier area under the handguard.

A 1:9 barrel will shoot both, but isn't fast enough to stabilize the newer 72gr, 75gr and 77gr bullets that some of the elite units are playing with in the sandbox.

Perhaps off topic to this thread, but that's not necessarily true in every case. Some 1/9 twist barrels shoot heavier bullets fine. I've shot a lot of 75gr. and some 77 gr. in my two RRA(Wilson) 16" and one Bushmaster 20" 1/9 twist barrels. They shoot both very well at 100 yards.

Some barrels do better than others. 1/9 is right on the edge of stabilizing these longer rounds. The generally accepted explanation for this is that the barrel twist number of lower cost barrels isn't perfectly the same for every rifle. Some 1/9 barrels may be a little closer to 1/10 twist and some may be closer to 1/8 twist.