Tag Archives: COLT


After taking a look at the parts and guts on the Colt 6940 Piston carbine last time, it is now time to show the results of testing the carbine for accuracy and reliability.


For my accuracy testing of the carbine, I used the Leupold 18x target scope on a Larue SPR mount and my usual bags and test as I am wont to do.  I fired all groups shown at 100 yards and 200 yards using a variety of match factory ammo as well as my own match handloads. I also  fired the gun at 1,000 yards and 500 yards in my typical test to push it as far as possible. Once again for the long range resting, the 18x target scope was used,

To make the job a easier , I did use a SSA trigger int he carbine this time.  The reason for using the SSA trigger instead of the milspec trigger this time, was because there is a reputation of piston guns having a little less accuracy than DI guns.  My thinking was to try my best to eliminate anything I could that may give results that I , or anyone, may be biased to attribute to the piston system. So I used the match SSA trigger and a very secure front rest and sand bag set up from a bench.   I wanted to get every bit of accuracy I could from the carbine.


Above are the 5 rounds groups fired at 100 and 200 yards.  Due to limited amounts of some of the test ammo, I was only able to use 5 round groups after zeroing the gun and settling in.   While all groups are what I considered great, I did notice small changes in the group size with certain match ammo  from the DI guns to the piston. When using the DI carbines some of those brands shoot better  in about every DI carbine/rifle I have used and other bands are not as tight while it seemed to be the opposite with the piston.  Now, this is a small amount and not worth even talking  about in a practical matter, I only noticed because of firing the ammo through so many guns that I was able to notice the change,  Practically speaking , and from the outlook of field use, It is irrelevant.  You can notice the SSA and the TAP strings vertically at 200 yards and beyond,  I shot these at a later time with a cold clean bore and with a cold dirty bore and hot dirty bore. Those brands of ammo string vertically in the gun after you get to 200 yards.  Again, practically speaking, it is not enough to matter or worry about in a carbine  with a milspec barrel meant for fighting.  It may be just this one gun, or may be those brands are sensitive to a piston operated carbine. I have no idea.  But I present the info to you regardless.


Above is the target with the boxes of some of the brands tested. Below is a closer picture of the groups for closer inspection.


After seeing the results of the groups and being pleased with the accuracy , I determined it was worthwhile for long range testing.  With the guns potential in mind, I and my friend loaded up and went to the mountain top strip job for the long range testing 3 weeks ago. Weather was mid with slight winds.  Being on top of the mountain, it is hard to catch a windless day.  The wind without fail travels right to left and can be seen on target as can be seen in almost all long range test targets from me.

I used a cardboard target with two orange panels to make target ID easy and to give me a better aiming point.  Readers will notice I have used as variety of different target types and styles for long range testing,  This is an ongoing project of mine to determine the best target and color combination to make long range testing as easy as possible to center the target in the optic for precise aiming,  This system worked well on a sunny day, but the color or the paper was not much help late on when the sun was not shinning on it directly.


The shots fired at 500 yards , I circled with a sharpie. The 1,000 yard shots  I drew a square around them. The one hole with a star like squiggle drawn around it, is a hit that I am not sure is a 500 round or 1,000 yard shot. I thought it was a 1K shot but later I thought maybe I intended to mark it when I fired the 500 yard group.  So I marked it as a 500 shot to not give myself the benefit of the doubt  and make a note of it.  I feel it is more honest in this case to just call it as a 500 yard hit.   On top of that, the 1,000 yard string obviously shifted to the bottom left corner and I feel it was unlikely that one of the 1K shots hit that far right and high.

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The first fired 10 rounds at  500 yards using the Black Hills 77 grain MK 262 MOD 1 ammo.  Five hundred yards is not a serious challenge for a quality carbine. Especially off of a bench rest and bags with an 18x optic.  As per my usual method, I fired 10 rounds on a steel target gong to confirm my zero. I think fine tuned on a few skeet I lay around the target to make sure it is refined, then fire my “record group” of 10 rounds.  As you can see I missed the target completely on one shot and of course the specially marked hit that may or may not be a shot at 500 yards. So NOT giving myself the benefit.  8 out of 10 rounds on target at 500 yrds.   But, this is a very good group.  The wind showed me some mercy while I fired the 10 shots and it shows.  Once again, you can see the vertical stringing sneaking into the group.

Last I fired 20 rounds at 1,000 yards with 6 hits and then the hit in question that may have been a seventh round hit,  Once again, not giving my self the benefit, I toss this shot out since it is in doubt, I give a count of 6 hits. The wind at that distance carried the shots further to left and I used several minutes to get me on the target this much.   For the 1,000 yard group,I switched to my personal hand loads,  It is a pet load that out performs factory ammo and is hot enough I do not share the load data.  Now, whether it shoots better at this range or I just have more confidence in it, I have no idea really. But confidence is a huge factor, so I stick with it since it has always performed well for me.   It takes extreme effort to get a 16 inch barreled carbine on target at 1K.  Using a 20 or 18 inch barrel or better yet, a 24 inch barrel 556 gun is like heaven compared to the gymnastic it takes to get a carbine on but it can be done.  Once again, I show it, just to show what a person can do with an M4.

The  6940Piston has some benefits in the long range testing in the fact that it comes with the SOCOM profile heavy barrel that is a big help. If the piston does disrupt the barrel from its extra movement and vibrations, then the heavy SOCOM barrel meant for harsher full auto firing schedule, helps cut this down possibly.

Last we come to the reason that the piston M4 carbine is supposed to exist. More reliability and especially in hard use with little cleaning, And of course in a military context, full auto fire with little cleaning and lube.

Last week friend of Looseournds.com and my neighbor , Tug Valley Armaments brought his full auto guns out for us to do some hard testing of the Piston Colt.  Since getting the gun in the mail from Colt. I have rnot cleaned or lubed the gun.  After 784 rounds of no cleaning and no lube, It was time.  We put the upper on the full auto lower and fired up a few 40 round Pmags to get it so hot, it took glove to even hold it by the  KAC vertical fore grip.  I stuck a full surefire 60 round mag in the bone dry, very dirty gun with zero lube on it and held the trigger down until empty.

The gun went through the magazine without issue. Let me tell you it was hot before I fired the mag, and it was smoking after., We got the carbine dangerous hot.

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You can see the barrel of the carbine smoking from the heat of the 60 round mag dump after not taking a break after also firing through five Magpul 40 round Pmags and various USGI 30 rounders.  There was no problem form the gun. It ran wonderfully.  I cannot make any dubious claims of the BCG being cooler because it was a piston though since by the time I stopped shooting even the receiver extension was hot to touch.

One observation we did not expect is that the gun on full auto  would not run with the full auto lowers carbine buffer.  We slapped the upper on the Class III lower and left the buffer it had in it in place. I went to auto and it was semi auto only.  After thinking about it a second, we put the H2 buffer that comes standard in the  6940Piston, in the NFA lower and the gun ran perfectly. Just more reason why I have always appreciated Colt giving at least the H buffer in their carbines and heavier buffers based on what the  gun was intended to do.

The piston 6940 is a superb piston AR15 carbine. If you are the type who thinks he has to have a piston to kill the commie invasion, I can not see you being let down by this gun or find any complaints.  If you just want a great gun and you like this one and do not have any strong thoughts on the piston vs DI, you are gonna love this gun.  If you are a DI die hard guy like me?  You are still going to really like this gun.   I won’t be switching to piston nor do I feel the need to, but I am impressed by this gun. I think the DI does edge it out in accuracy with match ammo, but in practical field use it is not really a factor.   Since I used match ammo for the testing in the part, I will be using milspec issue ammo testing in the next part  to see how it does and  possibly a direct shoot off  between the 6940 Piston and the standard 6940 DI gun.  So, if you are interested check back for that info.

Colt 6940 Piston Carbine Test & Review Part 1

The  idea that the piston operated AR15/M4  would be an improvement that fixes all of the perceived short comings of the weapon has been something that has gained ground in certain corners since the dubious “dust tests” and H&K marketing from a bit over 10 years ago now. Miss-use by users in the GWOT and careful lobbying by certain companies has put the idea that the DI system is sub-par in the minds of some of the lesser educated.   In fact ,if you did not know better you would think the piston operated AR15 did not exist until HK came out with the 416.    Truth is Colt had already developed a piston operated AR15 since the 60s and had been playing around with it ever since. If you look close at the front sight, you will see some details that pop up a lot later.


Later Colt, in 2005-2006 colt started showing pictures of another piston gun they called the LE1020. It was a monolithic railed upper very close to the current 6940 uppers. It lacked the QD sockets,and some other small refinements but it was clear the idea was being refined. All this before others had started with their piston campaign.  Yes, colt had been making and refining piston AR15s for a long time. Getting it the way they wanted it before deciding to offer it.  We did not see the LE1020 hit the market back then because it was found the market and the Military was not that interested in a piston gun.  It took ignorant gun writers and HK marketing to convince a lot of people that they could not like without a piston operated M4.  Never mind some of those early piston ARs chewed up receiver extensions, suffered from carrier tilt, weighed a ton and were not very easy to modify.

If you are new to AR15s you may have missed the bright spike that was the peak of people wanting piston guns because so many believed a little dust caused a M4 to malfunction and History channel documentaries that were more or less HK 416 advertisements.  That has craze has evened out now a days and while some SOF use piston M4s, the rest of the army found out the M4 with its DI worked just fine witht some oil and not trying to use the M4 as a SAW.  But in that time, companies had some time to tweak the piston guns to get them to work right.  Among those was Colt, who refined their piston model from all those years ago before any one else had even thought about making a piston AR15.

With that, we come to the present day. A few weeks ago, Colt once again was nice enough to send me a shiny new Colt 6940Piston for my grubby little hands to test and abuse for other peoples amusement. We will take a look at it in this first part of a longer review and test. just to get to know it a little. stick our nose in its nooks and crannies and put on the old rubber glove and tell it to bend over so we can get to know it a little deeper….


The Colt 6940P ( Piston) is essentially a regular 6940 from the outside. The lower is standard Colt milspec minus the full auto FCG of course. The buffer that comes with the P is the H2. This is standard issue with the gun as it comes with the the heavy SOCOM profile barrel we talk about in a moment.  The SOCOM profile M4A1 barrel is always combined with the H2 buffer in Colt models. Piston guns with standard A2 flash hiders will have a bit more felt recoil than DI guns, and the H2 buffer can smooth that out, Though to be clear that it not why it is in the gun.  As I said, with colt, the H2 buffer always is paired with the SOCOM barrel, but it is a nice side effect.


Looking at the picture of the buffer you will note there is no shaved metal from carrier tilt or eaten up lowers which was common on some other companies piston conversions.


As mentioned, the barrel is the SOCOM profile, which was  made for the use on M4A1 full auto carbines.  The cut flats a few inches from the front sight are for the M203 to mount around. The barrel is free floated in the monolithic upper. The free float 6040 uppers will give you every bit of accuracy the barrel is capable of. I have never seen a Colt monolithic upper that has given mediocre accuracy when using good ammo, but the piston parts may make a difference. We will see in part 2 with accuracy testing.



The upper rail is standard 6940 and the lower rail removes the exact same way.  You can see just like the DI guns, this one has the QD sling points. The piston parts are hidden under the FF rail.


The piston comes out very slick  and is retained neatly with a push pin much like those used for the lower. You simply push it to the side and slide the piston out.No muss no fuss.


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The piston is Colt’s design with the articulating link. Not much to say about it since its a piston. Very robust.


Since we have a piston, we don’t need a gas carrier key.  The early Colt P guns had a bolt on part, just like the gas key, this was changed to the current model. It is machined out solid on the carrier . No bolts or staking to worry over. Not that you ever really had to worry about a colt stake job in the first place.   The Bolt carrier group fields strips for cleaning just like the standard non-piston   BCG



The rear of the carrier has rails machined on it to make sure you get no carrier tilt. No tilt means your lower will not get chewed up like some of the early HK416 and conversion kits rushed out on the market.  The truth is, the AR16 was not meant to be a piston gun, so careful changes had to be made for it to work out in the long term. With the rails to the rear of the carrier and a steel block added to the upper receiver, tilt is a non issue on the 6940P.  In the picture below,  you can see the part added to the upper.  Buyers of even DI guns will notice this on newer 6940 DI guns and the 901 as there are plans to make piston 901 eventually and it simplifies production to make them all the same.



Above is the upper with lower rail hand guard removed with piston and bolt carrier.


From the outside, it looks like the regular 6940 until the educated eye looks at the front sight. The gun handles and balances no different, thought the SOCOM barrel adds a little more weight.  To get ready for long term hard shooting, accuracy testing and full auto torture tests, I have added my favorite TD grip and Colt factory ambi safeties.  For drills and general use it now has a CompM4 a B5 stock and a Knights  600 meter BUIS.  Part 2 of the review will be the accuracy testing for group, long range to the weapons extreme limit and more.  Full auto fire may be in part 2, or it may be moved to a part 3 for torture test and taking a look at cleaning the piston gun. Less fouling is often touted as one of  a piston gun’s biggest advantages so it is possible I do a part devoted to that.


A rare failure, the broken AR15 forward assist.

Broken AR15 Forward Assist

Pictured above is the broken forward assist from my Colt 6933.

I’ve see a few forward assists break. Every time it has come as a surprise to the shooter. Usually what happens is a shot is fired, and the action ends up locked closed, and no one is able to open it using normal clearing techniques. In my case the action locked open after ejecting a shell.

It can be hard to diagnose a jam caused by a broken extractor simply because you can’t see that is what is preventing the bolt carrier from moving.

The best procedure we have found to free up a stuck bolt carrier from a broken forward assist is to:
1. Remove magazine, keep muzzle pointed in a safe direction.
2. Hold rifle with the ejection port down, barrel parallel to the ground.
3. Shake rifle while attempting to move bolt carrier.

Then usually it wont take much to get the action moving again. Immediately clear the chamber and remove the bolt carrier group from the action and remove any loose parts(like the forward assist pawl shown above).

Over the years, I have come to believe that the forward assist should be reserved for emergencies. In practice or on the range if a round does not chamber discard the round or inspect the firearm. I have met many(most former Army) that hit the forward assist after every reload. If your rifle isn’t chambering the round under its own power, there is something wrong with either the rifle or the ammo. Forward assists very rarely fail, but there is no point in slapping it around unless it is an emergency.

Quick review of the Larue MBT trigger.

Recently LaRue Tactical ran a sale on his 2 stage match trigger called the “Meticulously Built Trigger”. I bought one for during this sale for $125.

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The MBT trigger came nicely packaged, it looks good and appears to be well made. The disconnector is riveted in place making the trigger a little easier to install than a Geissele SSA trigger.

AR15 Larue MBT Trigger

I noticed the pins that came with the my MBT trigger were slightly longer then the average trigger/hammer pin. This caused them to stick out from the lower just slightly. In the picture below you can see the trigger pin sticking out from the receiver. The hammer pin is reversed and is sticking out similarly on the other side.

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When I compared this trigger to the Geissele SSA, I found I preferred the SSA by a very small margin. I find the second stage to be just a touch stiffer than the SSA. When the MBT was new, it was noticeably stiffer and longer pull than the SSA, but after being greased and a few rounds fired it feels mostly similar to the SSA. The MBT used to be priced at $250, the SSA $220, at those prices I would always recommend the SSA over the MBT. At the sale price of $125, I don’t think the MBT can be beat. Now I see the MBT is priced at $200, which makes it better competition for the Geissele SSA.

The MBT appears to be a good trigger, but honestly I currently prefer the SSA a bit over it. The MBT is a very nice trigger and if you want one, get it. I am looking forward to seeing how it feels after it has more rounds on it and is better broken in.

Modern-Retro Hybrid Colt 1911 Project


I have always liked the look of the pre series 70 commercial Colt 1911s just as much as the US military issue guns. There is no doubt that those older vintage guns have a huge amount of appeal.  I have been  looking for a near mint example of one for my own collection and uses for years but they are hard to come by at a price I am willing to pay.

So over the last year I got the idea to sort of create my own, at least in spirit.  The idea was to take a modern plain Colt government model and slowly put it together to resemble a gun one might have walked into a store and bought before WW2.


The first thing I did was change out the main spring housing.  Colt was kind enough to send me a MSH from their no discontinued line or re-issue 1918  WWI pistols. It is beautifully blued and highly polished with the lanyard loop.  Looking at it shows the amount of polish and beautiful bluing that went into those early guns that went to the trenches in the Great War.  Like all colt made military parts for the 1911, it dropped right in.

The next thing I wanted was the early original pattern of the safety lock.  Unlike modern safeties, it has a smaller shelf for the thumb to hit. There is a reason it was made this way despite what some thing. It acts as a surface to tap against for when detail stripping some of the other pins and parts on the gun. You can read all about it at rangehot.com  in the posts by John Travis on the 1911 and  the genius and thought that went into it.   That aside, it is correct for that time period. And I personally love the way they look. It is not a bit hard to hit to take the safety on and off. Once again Colt came to the rescue for me when I could not source one any where else. Midway sales them, but are currently out of stock, so if you want one keep checking back under their listing of colt parts.

The safety came off the line and had yet to be fitted for 1911s so I had to do about 30 seconds worth of careful filing and fitting. With that very little bit of work I got it fitted correctly and after function checking it. I shot it to make sure.


Lastly, I found a WW1 reproduction 7 round magazine to go with the gun. These original mags came with a lanyard loop as well. I have heard a variety of reasons why the mags had loops as well as the gun. One theory is that the  US issue lanyards at the time meant for revolvers would not fit through the loop on the new automatic pistols so the asked for a loop on the mag in the meant time while they sorted it out.  I am skeptical about that, but I have no idea. I think it is for cavalry being able to not lose the gun or the magazines during a reload while on horse back.  In those days magazines would not have been looked as as nearly disposable items like they are now. So it seems reasonable to me to think that the cavalry wanted a way to retain the mag without having to use both hands while riding a horse on a full gallop.

Eventually I will replace the hammer with the original style and I may or may not go to a shorter trigger,  I think it will be more of a hybrid of a 1911A1 and a 1911 than fully one or the other. Call it a 1911A0.5 for my purpose. Of course it will still have its colt SS forged barrel and bigger high profile government model sights that can actually be used just as effectively as any other modern sights.  So maybe I need to think up a better name.

For now I am in love with this pistol. The new gun  is a plain model as it comes, but it has a very attractive highly blued finish. Not as mirror like as a TALO model, but not flat black. It is basically the modern day government model from the past, Before it was the MK IV series 80 and before that the series 70.  It is very close to the plain USGI 1911 of the past 100 years but with a bit of improvements for modern shooters. Example being a SS barrel, taller sights that are very easy to use but still can pass as GI sights for those who want that look, a slightly beveled mag well on the inside that helps with faster reloads but does not change the outward looks and a slightly enlarged ejection port.  It is the last pistol in the lineage of the GI issue pistols and it is fully capable of going out of the box and right into a fight but with no frills. No ambi-s safety or forward slide serration. But thats OK.  It is meant to be a throw back to an earlier gun but still be  capable as if if you need it.

I carry this pistol often, for special events, I guess it is essentially a BBQ for me., though I shoot it a lot. I enjoy shooting it for pleasure and for formal target or bulls eye type marksmanship. I do train with it just to stay on top of using a 1911 without a ambi safety, but not like I do with my more modernized every day CCW 1911.  My EDC is a Colt 1911XSE in stainless steel. I do love carrying this pistol that is my loving tribute to an earlier time.


Colt XM16 Found In Cambodia Still In Service

We all hear or read the second hand stories of AKs turning up all over the world still in use. But often the stories of  M16s from long ago are not talked about as much.  That does not mean it does not happen.  Recently some one shared on facebook a picture of a XM16 Colt still being used in Cambodia.

Left there during the war, it still serving its owner all these years later. A  bit rougher than it left the US, but still working. And with some customizations!  Apparently even in Cambodia  the urge to customize the AR15  is hard to resist.

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