A Throwback Colt Friday

This old cover of SWAT caught my eye the other day. The gun on the cover is what Colt refers to as the R6400 as their factory model number. The keen eye will notice A2 furniture but an A1 rear sight. That’s because it uses the upper and lower of the older SP-1s but was upgraded with A2 fore arms, grip, buttstock, delta ring and the new A2 government profile barrel. Also a A2 flas hider and a front sight. The barrel of course uses the 1/7 twist t use the then new “SS109”, AKA, M855 green tip. Very new at the time. Cover date shows 1984 so this was even before the Army adopted the M16A2 rifle.

The roll mark on the lower was AR15A2 SP-II. As the older uppers ran out, Colt then sold the R6401 which was the same gun but with the actual A1 upper with a forward assist. Next came the R6500 which was same gun with the C7 upper. That was the A1 upper with forward assist but with a case deflector as used by the Canadian rifle.

Finally Colt would use up all those uppers and sell the R6550 which uses the true A2 upper to go with the rest of the upgrades. The lowers would continue to be the older slick side SP1 no fence A1 profiled lowers for a while before being changed over to the current A2 lowers.

During this time, Colt stilled used the “large hole” upper and lowers for the front pivot pin. Contrary to internet experts this wasn’t done because colt hates you but was something the federal gov ( read ATF) made them do so as to be able to sell semi auto Ar15s to the public. This was foisted on them all the from the start of the SP1 civilian sales. Other changes were the semi auto carrier and a few other things. But that’s an article for another time.

There are offset pins to let you mate a large hole upper or lower to a modern or “small hole” or “milspec” upper and lower and it works pretty nifty even though you will need a screw drive to separate the upper and lower. Eventually the gov relaxed these crazy requirements and the ever law suit adverse Colt stopped all modifications to civilian guns and now sells the with standard pin holes, trigger groups and with M16 BCGs. Just as God intended.

Field Accuracy Of The MK12 (Part 1)

The MK12 Special Purpose Rifle has been around 20 plus years now give or take and has achieved an excellent reputation for accuracy and effectiveness. I won’t go over it’s history and development here except to say it was developed as a light weight sniper rifle for special operations forces. It’s use in the GWOT went on to prove it as an excellent variant of the infinitely adaptable AR15.

Since then civilian buyers have “build” copies and nearly perfect clones of the rifle. It’s been used arguably more in the civilian world than the military world at this point since it is now no longer officially used by the military. It’s proven to be an excellent precision AR15 in every way even if it is “dated” compared to the never ending marketing to selling us lighter and lighter and more and more Gucci new models and variants with debatable improvements.

One thing I have noticed about the MK12 when it comes up in discussion is the same old subject about its effective range when it comes to accuracy. A lot of people seem to think its a 600 yard gun. Of course other people who know better will shoot them further but that doesn’t seem to make much of a dent in the never ending opinions of online commenters. So once again I decided to demonstrate what it can do and push it to its extreme limits. This will be ongoing for the next few months. So let’s get started.

My first thought was to start this off with all the usual sand bags and rests and all the stuff to replicate shooting from a bench on a range to milk accuracy. Then I decided maybe it would be better if I shot the gun at long range just like it would have been used in the field, bipods and laying prone or across a pack. If I couldn’t get results from there for whatever reason I would use a bench , rest and bags.

Shooting from prone using the ATLAS bipod and no rear sand bag, I shot the rifle out to 900 yards. Target used was the official 1,000 BR target with scoring rings. I used this instead of a steel target so we would have something to actually measure by and to show results. Ammo used was the ammo developed for the SPR. The Black hills 5.56MM MK 262 ammo with 77gr. Sierra match king bullet. I cheated a bit with the optic by not using the optic issued with MK12s. In this case to better see the target and make as precise of shots as possible, I used a NightForce 5.5x-22x. This insured enough elevation as well as magnification for long range. I will be using this optic for the further testing or this series. In this first test we are looking at the MOD 1 version of the MK12. Using the KAC fore arm, a douglas barrel in 1/7 twist and the usual ops inc muzzle break. Lower is Colt with SSA trigger. Upper is Colt and Colt BCG with all the correct parts etc. Future articles will hopefully include the MOD 0.

I caught a perfect morning to do this initial testing. It was 65 degrees with no humidity and a 6 o’clock wind that wasn’t even 5mph. After fine tuning the zero, I fired 20 rounds for “record” on a fresh target.

Target above is for final record group. It wasn’t the first attempt as I needed some time to fine tune the zero and settle in after a little practice. Since I am trying to show what it can do at it’s best, I am not bothering to show you my warm up targets since they were not shot with final zero and MK262. It’s expensive so handloads stood in till I was ready.

The group probably looks as crappy to you as it did to me when i first drove down to inspect it. So to put it into perspective I put up a human like target against it since that is what the gun was meant to be used on.

Yep, I had a couple of flyers that I can’t explain. No excuse. I’m not as good as I was a couple years ago. It happens. I’m pretty happy with this. Had my spotter been my preferred partner and I shot from some sandbags I believe I may have been able to tighten this up a bit. Hand loads or the new Federal 73grain Berger gold medal load may have tightened it further. Those will be next time perhaps. I think the Q target demonstrates the ability of the MK12 with its issue ammo in knocking down human bag guys pretty well though.

In part 2 I will take the target out to the full 1,000 yards. This was my intention for part one but I anticipated terrible mirage from heat and wind and set the target up a little short. The temp and wind never did rise to the level I thought it would though and I was trying to shoot in those perfect conditions while I had the chance instead of wasting it driving back to re set the target. Next Time… 1,000 yards and maybe beyond.

Comments on the Army SMG competition.

We had someone here comment on how wrong it was that the Army adopted a foreign weapon for the new SMG contract. So I felt like looking into some of the other submissions.

As far as I can tell, the first list was narrowed down to thirteen options. I got this list from ArmadaInternational.com, the article was written by S.W. Miller. It lists guns I did not see on other sources.

  • Z-5RS, Z-5P and Z-5K Sub Compact Weapons; Zenith Firearms
  • B&T MP9 Machine Guns; Trident Rifles
  • MPX Sub Compact Weapon; Sig Sauer
  • 5.5 CLT and 5.5 QV5 Sub Compact Weapon; Quarter Circle 10
  • PTR 9CS Sub Compact Weapon; PTR Industries
  • MARS-L9 Compact Suppressed Weapon; Lewis Machine & Tool Company
  • CZ Scorpion EVO 3 A1 Submachine gun; CZ-USA
  • CMMG Ultra PDW; CMMG
  • Beretta PMX Sub Compact Weapon; USA Corporation
  • Heckler and Koch Defense Inc for HK UMP9 Sub
  • Angstadt Arms Corporation for Angstadt UDP-9 Sub
  • Noveske Corporation for Noveske Sub Compact
  • CM9MM-9H-M5A; Colt’s Manufacturing Company

As I said, this list is different from others I have seen, but lets go through it anyways.

Zenith and PTR submitted guns based on the MP5
Zenith, which sources from MKE (Turkey).
If I understand correctly, PTR is all American production now.

The Quarter Circle 10, LMT, Angstadt, CMMG are AR15 based.
I haven’t found photos, but presumable the Colt and LMT offerings were also.
The Sig MPX is based of the AR15, but they have switched to a piston system.

Trident submitted the B&T MP9, a Steyr design being built by B&T.
Beretta’s PMX is a design that bought from B&T.
And the winner of the competition was the B&T APC9K PRO.

It appears that most of these guns are simple blow back design. The MP5s, the CMMG, Sig offerings are not.

After this first list, that offer was pulled, and the nub submission was:

  • Angstadt
  • B&T
  • Global Ordnance
  • Shield Arms
  • Sig
  • Trident Rifles

B&T and Trident both submitted B&T firearms. I believe that Angstadt and Shield both submitted blow back operated ARs that use Glock mags. Global Ordnance may have submitted the blow back operated Stribog.

From everything I read and saw during the first announcements I was sure the competition was being written for the Sig MPX. Since it has the same manual of arms, some parts compatibility with the AR, I expected it to be a sure win.

The majority of the original submissions were not made in the US or American companies. And almost all of the American submission were AR based. There really hasn’t been much innovation by way of pistol caliber long arms in the US. CMMG came up with a delayed blow back system for the AR, but I read that makes hollow points and various bullet designs unreliable.

B&T really must have done something right. In the recent past, they designed the P26, which was purchased by Beretta and renamed the PMX for use by the Italians. They made a double action/single action SMG called the KH9 that could use B&T or Suomi mags (like the 50 round coffin mag). They produced a model that could take the Suomi drum. This weird gun had a 22 pound first trigger pull, then a 2 pound trigger pull after that. WTF? They are making the MP9 and the USW machine pistols. Along with a lower cost SMG the GHM9. Their high end series, the APC, is available in 9mm, 45ACP, 5.56, .300AAC, and 308. They might have made more unique new designs than anyone else in the past couple of decades.

Anyways, I am curious what the official designation of this new Army SMG. It would be funny for it to be called the M4 Submachinegun. But I bet the Army is going to give it a rather high number.

Random Pictures

Colt ACR, built to fire duplex rounds. It is said it had 40% less recoil than a M16A2. Note the stock which was a predecessor to the SOPMOD stock.

Much to my dismay, some years ago, I saw a near complete set of Colt ACR parts for sale individually. A bunch of different people bought individual parts. I think it is a real shame one person didn’t buy it all to build a semi auto one.

Who wants to play “spot the error” in this clip from an ad for the SEALs.

More On Colt Monolithic Upper History

A couple weeks ago I did the “10 years of the Colt 6940” post and then a few days after realized I had left out some pretty neat stuff from the history of the Colt monolithic uppers. Over the last 10 years there was some other monolithic upper rifles and carbines from colt in some variants that we never saw displayed at any of the shows

This rifle length barrel and monolithic rail was very interesting. It came about right around the time the USMC was making noise about putting collapsible carbine type stocks on the M16A4. Supposedly making it the “A5” Never happened and neither did this variant. I would very much like to have had this gun but with a match barrel on it for a sort of 694X SPR precision rifle.

This is sort of a compromise of a M4 with a RAS but with the 6940 type folding front site and a piston gas system. Meh.

Above is a piston version of he Colt SCW. We did later see this side folding and collapsing stock trickle out via ebay and gunbroker etc. But so far nothing has been offered for sell as a standard or special order option. Later photos of more refined versions showed a DI gas system and a full monolithic 6940 upper. The side fold stock is pretty nifty but required a much modified bolt carrier group.

The most successful of the 694x series variants for military markets is the Colt IAR. Made up as Colt’s option for the USMC IAR rifle the Colt IAR is made up with a heat sink in the lower removable handguard and barrel more suited to full auto fire. A decent amount of uppers were sold on the civilian market,Howard has one, and some other countries use the full auto military version as IARs and even a sniper support weapon in the case of Mexico. You can see a video of friend of the website Alex, shooting his Colt IAR upper on a full auto lower below