Importance of "Mil-Spec"WRT Colt AR 15's?

AR/M4 AR General Discussion
1

I wanted to ask a question to this community regarding exactly what “Mil-Spec” is;

I assume, as the name implies, that it is a sort of standard held by the military for their required specifications for firearms and other gear.

Having said that, I was recently told that Colt AR 15’s are NOT made to Mil Spec standards…I dont know if they exceed them or not, but mil spec standards they are not. I have also heard that Colt does NOT have any contract or agreement with the military to provide them with their weapons (at least the AR 15 or M4)

Now, my question is, does it really matter? Also, does Colt really have any sort of contract with the military to provide them with the AR 15? Does ANY company that makes AR 15’s have the contract? Should this matter to me in the purchase of my weapon? Should I let Mil-spec or non mil spec determine which AR I should buy?

I have noted that Colt is one of the preferred brands among many of the people in this forum, and rightfully so! I happen to think that Colt firearms in general are excellent (I own 2 1911’s and I think they are fantastic weapons!)

But my main question here would be that If Colt does not make their AR’s to Mil Spec standards and they do NOT have a contract with the military, then why are some or all firearms dealers discouraged (by Colt) to sell their firearms (AR 15’s that is) to the civilian market? I ask this because the cost of an AR 15 in a gun store can be quite high…usually DOUBLE the cost of some of the other brands.

I was told by a local gun store owner that this was because of lack of availability of these firearms from Colt, meaning Colt really does not want to send these weapons to local gun stores because they want these weapons to go mostly to LE and Military ( he had ONE Colt AR 15 in the store ). I then asked if Colt was contracted by the military to provide them with their AR 15’s, and I was told no, because these were non Mil-Spec weapons! This led to several questions in my mind, hence this post.

I am sorry for asking all these questions which may seem trifle to the more knowledgeable members of this forum, but the more research I do about these weapons, the more I find out and the more I want to discern between rumor and truth, and exactly what should really matter and what should not in the purchase of my AR.

Based on what I have seen so far on this forum, I know I am in the right place to find the right answers to these questions.

I thank you for taking the time to read my post!!

Abdon

2

AR15’s are not “mil spec”.
Colt supplies M4/ M4A1 Carbines, as well as M16A2/A3/A4 rifles to DoD. FN supplies M16A2/A4 to DoD. Gun stores do not sell M4/ M4A1 Carbines or M16A2/A3/A4 Rifles.
The errornet is not always a valid source of information. Compared to gunstore employees however, the errornet is the gold standard.

He is correct tha AR15’s are not “mil spec”. Both Colt and FN supply M4’s and M16’s to the military (and they are the only ones who supply a standard “A”).
Colt does not discourage civilian sales. They are selling everything they have to the military, to the tune of 8-10k a month- depending on whose numbers you source). Colt has allegedly purchased additional machinery to keep up with the military demand.
From a business standpoint, it only makes sense to sell to the military and avoid other issues with other then mil sales (this goes back to agreements with state and city).
The availability of Colt AR’s has always been low. Soon you may never see another one in a store.

3

“milspec AR15” is obviously an oxymoron, but Colt probably comes closer to more of the the milspecs that actually matter than most other companies. For example, their lowers may not have the right pin sizes but they do have the right aluminum with the right anodizing and the right dry lube film. Most of their barrels have the wrong twist rate and don’t have as much chrome as they should, but they are all MP tested.

4

Here is the M-4 mil-spec for your enjoyment:

http://www.biggerhammer.net/ar15/milspec/MIL-C-71186_(AR).pdf

5

Thanks Ammotech, I didn’t know it was available on-line.

6

What is the “right” twist rate? The spec calls for 1/7. They produce the odd 1/9 for the LE/civ market. Had four and sold them to buy 1/7’s.

Not enough chrome? That’s a new one!

I am looking at a gen-u-ine Colt M4 barrel: 5.56mm NATO C MP 1/7. How can I discern that it has insufficient chrome in the barrel and chamber?

ETA: Are you referring to the post-ban rifles that had chrome only in the chamber? Simple solution: buy only Colt barrels with factory-installed flash suppressors. They are fully chromed.

7

1/7 is for the M855/M856 bullet the older AR/M16 used, I think, a 1/12 twist for the M193/M196 rounds. The civi/LE 1/9 allows for a greater number of bullet weights to be used.
I shoot M193 because it is cheaper but if I want to change ammo all I would need to do is re-zero vs. a bbl or upper swap.

8

Sub, I should have been more specific but you already knew the info. The milspec says 1/7 twist with a chrome lined bore and chamber. Many of the civilian models are 1/9 twist with chrome lined chamber but not a chrome lined bore. The threaded muzzle is not a good indicator, my 16" lightweight had a threaded muzzle but was 1/9 without a chrome lined bore. Best is to stick with a milspec profile (M4, A2) with a 1/7 twist.

9

Actually, 1/7 allows for a greater range of bullets. It works fine with pretty much anything M193 or heavier. 1/9 is borderline with the heavier 77 and 75 gr ammo. Some 1/9 barrels will work and some will not. Mine didn’t.

10

That’s good data point. Maybe the determining factor on chrome is not only the FS but also the twist. All nine 16" Colt 1/7 LW’s I have are chrome lined. I was unaware Colt made a 1/9 16" LW. I have seen Colt 20" M16 barrels (so-called “pencil” but otherwise “standard”) barrels in 1/7.

11

I stand corrected; thanks!

12

Oh boy, here we go again!
After checking all the posts I came to the conclusion that 1/9" twist would give me the most options RE: ammo. Maybe not the most accurate, not milspec but the best compromise for all around use. My gunsmith says 1/7" is not good (while looking at my trusty AR Sporter 1/7", 20") But I know it to be very accurate out to 500meters with PMC ball 55 grain.

I start shopping for a replacement CAR & see the Colts are all 1/7"twist
but the bushy’s & RRA’s & S&W are 1/9" good? well maybe.
Then I see the heavy barrel Sporters are more desireable AR15 HBAR. I assume becuase of the “thicker barrel”. THEN I see Colt makes the ideal CAR for what I’ve learned so far announcing the AR6721 Tactical. Its got the preferred heavier barrel AND its 1/9" twist AND its a Colt Great!
Here’s a quote from colts site “The 16.1" (40.9 cm) heavy barrel with 1 in 9" (229 mm) rifling twist allows flexibility in ammunition selection.”

Now I read this thread & suddenly the the 1/7" twist is the preferred twist !?
That points me back to the LE6920…again sheesh

For the sake of further discussion, I came to understand the milspec 1/7" twist was the best for milspec ammo which is what the average GI is issued.
Us civilians have more ammo options so hence I concluded 1/9" was more forgiving…
For me, I just wanna shoot the cheap stuff i.e. PMC ball or 62 grain M193

…Can anyone clarify this endless enigma?

13

Soon you may never see another one in a store.

Pat, could you please elaborate on that?

14

I found this on another site regarding Twist rate.
"Twist

The barrel’s twist rate refers to the distance a bullet travels in the barrel to complete a full revolution. For instance, a 1/9" twist means that the bullet will make a complete revolution for each 9 inches traveled in the barrel. Heavier bullets require a faster twist rate to stabilize them correctly, but too fast of a twist rate will potentially cause a bullet to spin apart. For this reason it is important to match a barrel to the bullets being fired. In selecting a single twist rate for the survival AR, either a 1/7" or a 1/9" will serve the purpose best. These barrels are designed for bullets from 55 to 62 grains, and these are the weights that will most likely be used in survival. The 1/9 is the better of the two, but the majority of Colts/military barrels are 1/7."

I welcome all comments. verifications or arguments from you guys.
We’ll tackle the heavy vs light barrel later…

15

Pick your cartridge, then pick your barrel. :cool:

If you look at terminal ballistics gouge from folks like Dr. Roberts on 10-8 Forums, I think you will find among the best performers the Sierra 77 gr. HPBT match round used in the Mk 262 Mod 1 and Hornady’s 75 gr HPBT match (T3) used in their 5.56mm TAP. Few, if any, 1/9 barrels will shoot these accurately.

That’s why I sold 3 Colt 16" and one 20" 1/9 HBAR’s and went to 1/7 in everything except my 1/16 dedicated .22LR rifles. YMMV.

The 55 gr. and 62 gr. FMJ work just fine in 1/7 barrels.

16

Abdon, as you mentioned in another thread that you attended the West Palm Beach show it sounds like you and I live in the same area. Could you please specify who and what dealers you’re talking to that spout such nonsens so that I can be sure to avoid them in the future.

thanks.

17

The first step would be to stop listening to your gunsmith.

18

Thnx for your input Submariner,

I just bot a Colt 6721 tavtical carbine
It has the 1/9" twist , smaller handguards& the heavy barrel.
My intended use is to replace my AR 15 Sporter, Self-Defense, plinking, varmint hunting & potential survival weapon.
I hope that i’ve gleaned the best info from these forums as well as my own experience & feel I’ve made an informed buying decision.
Time will tell & thanks to all
anybody wanna buy a RRA that I’m gonna resell when I get it heh heh???
…look for it at the gun show in dallas soon.

thnx for all your input.

“gun safety is between the ears”

19

When you’re selecting a barrel you should consider all of the criteria. As a general rule, I want barrels in a lighter weight profile such as a “govt” profile, I want them to have a chrome lined bore and chamber, I want them to be MP tested and I would prefer that they work with the heavy 75 and 77gr ammo. I don’t shoot the heavy stuff very often except from heavier target rifles but I would like to have it as an option.

It happens that the barrels that meet the first several items are from companies like BCM, LMT and certain barrels from Colt and they are all 1/7 twist so they meet that last item as well.

20

You are welcome!

A 6721 was my first carbine upper back in '98. There are good 68/69 grain defense rounds. If barrel weight is an issue, you can have the HBAR turned/lightened or buy a replacement barrel. ETA: See Hoplophile’s post above.

The most important thing to do now is get good training. Then decide what to do next.

Welcome to Cult!:cool: