Colt - LE6920 M4 Carbine in 5.56/223 REVIEW

Colt - LE6920 M4 Carbine in 5.56/223 REVIEW

The BUY USED GUNS Team Review the Semi-Automatic Colt LE6920 Carbine in 5.56/223


Welcome to another Buy Used Guns Review! We have been lucky enough to have a fantastic rifle land on our tables to poke, prod and play with. The above photo shows the Colt LE6920 as is comes straight out of the box (literally, it comes in a cardboard box). The below photo shows what happens when the Buy Used Guns Team gets ahold of a new gun, good enough is NEVER good enough!


What do I get for my money?

There are a few versions of the popular AR-15 rifle you can purchase from Colt. Ours is the LE6920 model and comes with 1 x 30 round Magpul P-MAG (great mags), a manual and a padlock and key. You might not get many extras with the gun but it's a great rifle straight out of the box. The furniture supplied with this rifle include a Magpul flip-up rear sight, standard M4 style adjustable stock, standard pistol grip and standard M4 style handguard. You will also notice the standard A2 style front sight, which also serves as the gas block. The barrel is threaded 1/2 x 28 to accept most barrel accessories. Supplied and installed on the rifle is a standard A2 style flash hider. 



If you are not familiar with the AR-15 semi-automatic rifle then you best hit the web and do some research. It is by far the most popular semi-automatic rifle in the USA and has been in service with many militaries around the world. We won't go into much history of the rifle, the name speaks for itself. It uses a mechanism known as 'direct gas impingement' or 'DI' to cycle the bolt and chamber a new round each time the trigger is squeezed and a round is fired, thus making the operation semi-automatic in nature.

Again we won't go into too much detail. If you aren't familiar with this style of rifle then there is plenty of info on the web. Basically gas is tapped from the barrel (through the gas block), travels down a tube back to the upper receiver. This gas is then used to push back the bolt carrier group, extracting and ejecting the empty and fired case. The buffer spring and assembly (housed in the receiver extension or 'buffer tube') pushes the bolt carrier group back forward, picking up a new round from the top of the magazine and loading it into the chamber, ready to fire again. Simple!




Size and Weight

Quickly scroll down to the bottom of this review and you can see the specifications listed by Colt and the specifications as measured by us. What do these figures mean in the read world? It's a very well balanced rifle. The adjustable stock also helps to make the rifle more user friendly whilst still remaining above the legally required length for a rifle in Australia (check your state/territory!). 

Whilst the listed weight by Colt is quite light, it is unlikely any owner of this rifle would keep it stock for very long. We have weighed our rifle with the modifications and a full 30 round magazine, which is how it should be. Our rifle topped the scales at 4.3 kilograms or 9.47 pounds. The accessories and modifications done to this rifle have certainly added a bit of weight over the stock rifle weight of 6.9 pounds. The loaded 30 round magazine didn't help either! The length of the rifle (with Magpul CTR stock) is 825mm with the stock fully collapsed and 909mm fully extended. 

One aspect we didn't initially take into consideration is how far the 30 round magazine protrudes out the bottom of the rifle. It can prove cumbersome if you are used to shooting bolt action rifles with internal or short detachable magazines. You may wish to use 10 or 20 round magazines instead, but where is the fun in that? We did a lot of shooting off the bonnet of a vehicle and unless you have a bipod with long legs or a high rest the bottom of the 30 round magazine will touch the surface you are leaning on. One advantage however is the front of the lower receiver and magazine can be gripped when shooting if that's your preferred style. 



Shooting the LE6920

We tested the Colt in a variety of conditions utilising slow and rapid fire in the standing, kneeling and prone positions. What did we discover? The Colt is easy to shoot and very effective at what it does, which is sending rounds to a target as fast as you can pull the trigger. The rifle is very well balanced, quick to shoulder  We will break this section down into the key points;

Stock v Geissele Trigger

We did not measure the stock trigger however it was heavy, gritty and had alot of travel. We almost immediately swapped it out for a Geissele trigger. You can scroll down a bit to read our impressions of the Geissele trigger, we were very impressed. This was probably our most liked modification. If we could only do one thing to this rifle it would be swapping out the stock trigger. To be far on the Colt none of the team have ever truly loved a factory trigger from any rifle.



A2 'Birdcage' Flash Hider

The flash hider came stock with the rifle and seemed to do its job as advertised. We shot the rifle with and without the flash hider and it did help to tame muzzle rise, especially during rapid fire. Due to the bottom of the flash hider being solid with no vents it did not kick up alot of dust when shooting prone, a definate plus should you find yourself in that situation. 

Magazine Changes

Changing out the 30 round magazines is a quick and simple affair. Extend your index finger (if you're a right handed shooter) to depress the magazine release button and it will fall out ready for a reload. With about two thirds of a 30 round magazine extruding from the bottom of the rifle you will have no issues getting a firm grip on the magazine. 


As with most rifles chambered in 5.56/223, the recoil is almost negligble. We were able to manage decent control of the rifle when shooting rapid fire but unless you are firing a semi-auto 22LR your point of aim will wavour around a bit. The buffer spring or 'action spring' helps to absorb some recoil. You could further tame the recoil by fitting a muzzle brake however we found this would really be un-necessary unless your competition shooting with this rifle (an unlikely prospect in Australia!).


The Colt LE6920 (or any AR-15 really) comes with a simple lever to select between safe and fire. The Team at Buy Used Guns don't really use safeties on our guns as we believe the safest way to handle a rifle is with no round in the chamber. Whilst moving around with the rifle we had a loaded magazine inserted, the bolt locked back and the dust cover closed. When we needed to fire we simply depressed the bolt catch which released the bolt forward chambering a new round. 

The DI Price

The Colt has a Direct Impingement Gas System, which means it shoots hot gases and carbon back into the upper receiver to cycle the action. This does come at a price, which is a hot and dirty receiver after firing a lot of rounds. The more rounds you fire, the dirtier it gets. If you are used to giving your rifles a clean after every use no matter the amount of rounds fired, then you probably won't mind much. Our advice? If you are going to have a few shots with this rifle and clean it, you may as well make it worth your while and empty a few mags! The deciding factor will be your wallet. There is a lot of debate over DI v Piston AR-15's with many pro's and con's for each. You can even buy piston kits to convert your DI AR-15. Do your research and make up your own mind. 



We tested a few boxes of different factory ammunition and have shown the best and worst five shot groups below. The more expensive Hornady Match had the worst group which was quite suprising. Hornady Match ammo is well known to be quite accurate and with the 1:7 twist barrel the 75gr projectile should have shot a lot better.  The following groups were shot at 100 metres utilising a front and rear rest. 





Our handloads ended up performing the best as per the below photo. We imagine with further load development these groups could shrink closer to 1MOA. If it hadn't been for the odd flyer these groups would've been under 1MOA however we aren't going to shoot groups all day and just show you the best ones, that's not a fair representation of accuracy. 



Semi-autos are not known for fantastic accuracy when compared to say, bolt action rifles. We imagine a determined (or more skilled!) shooter could find some factory ammunition their rifle liked and shoot much smaller groups. Would we call the Colt LE6920 an accurate rifle? We would say it has the potential to be accurate however it seems to be picky with ammunition. We did test more factory ammunition not shown above (including Hornady SuperPerformance Match 75gr and Remington 55gr FMJ to name a couple) however we found it all grouped between about 1.8MOA to 3.1MOA. 



Stripping down the rifle for cleaning is a breeze. Removal of one pin separates the the upper and lower receiver for removal of the charging handle and bolt carrier assembly. This also allows you access to the inside of the lower and upper receiver for cleaning. The bolt carrier group can then be disassembled for further cleaning. All this disassembly can be done by hand without tools. We did find however that some pins were a bit stiff, no doubt because the rifle is new. After stripping the rifle down for cleaning numerous times we have found the pins have loosened up a bit. After you have stripped the rifle a few times you will have it down pat as it is not difficult by any means. This is great for field cleaning or attending to minor maintenance on the go.






We will run through the list of modifications and accessories we have done to this rifle, why we chose them and what we like about them.


Magpul CTR Stock, Rail Ladders and RVG (Rail Vertical Grip)

We chose Magpul gear due to its reputation of quality, reliability and strength. The CTR stock is a basic adjustable style stock, a simple lever is pressed to slide the stock back and forth along the buffer extension to the users desired length. The CTR also comes with a separate 'clamp' which eliminates the annoying wobble or play some stocks have between the stock and buffer extension. Magpul offer numerous accessories for the stock including different width butt pads, sling attachments and even cheek risers. (you may notice we have a sling swivel attached to our CTR stock.)

The rail ladders are simple rubber covers that clip onto a standard picatinny rail. This makes holding the handguard more comfortable and protects the rails from any harsh knocks. The RVG is a molded polymer front grip held on by two bolts. It has a great feel in the hand and helps to control the front end of the rifle. Although we didn't add the rear flip-up sight we will be leaving it on the rifle. It does not interfere with the mounting of the optics and weighs next to nothing. Our Magpul accessories are O.D. GREEN in colour. 




Hogue Overmolded Pistol Grip

If you have ever used/touched a rifle with a Hogue overmolded stock or grip then you will know the unique rubbery feel. It's great in getting a secure grip aided by the rubbery overmold and cobblestone texture. Replacing the original grip is a matter of unscrewing one bolt. This grip also has a small rubber 'extension' which fills the annoying gap between the grip and trigger guard. 



Daniel Defence EZ CAR 7.0 Handguard

When it comes to AR-15's with a fixed A2 front sight, changing over handguards can be difficult unless you remove the front sight or grind/cut it down. Luckily there are a couple options out there to avoid this. The Daniel Defence EZ CAR handguards come in two pieces and are designed to slip in without the removal of anything except the existing handguard. Once installed four tiny grub screws secure the rail in place. The handguard is made from lightweight aluminum and has been rock solid since installed. Our rail is seven inches in length designed for carbine length gas systems and adds plenty of rail for whatever accessories you desire. Another great feature is a small extension along with top of the rail which bridges that annoying gap between some handguards and the the rail along the upper receiver, as shown in the below photo. 




Burris MTAC 1-4x24

There is quite a few reviews of the Burris MTAC on the web already so we won't go into too much detail as this is a rifle review after all. Click on the following link for the manufactures web page for this scope;

We chose the MTAC for a couple of reasons, firstly the reputation of Burris producing quality scopes (The MTAC is no exception). The magnification range of 1-4 is perfect for a quick handling rifle of this nature and the illuminated reticle with bullet drop compensator for the 5.56/223 round is very useful. The glass is clear and overall quality fantastic. The scope just feels solid and reliable. The scope can be wound down to 1x and used like a red dot scope due to the design of the reticle and wound up to 4x for longer shots. We were comfortably shooting out to 300 meters with this scope however the reticle does have marks for 600 yard shots if your feeling game. 

Our MTAC came in a package with the P.E.P.R. single piece AR mount. Again this is a quality product from Burris and we could not fault it in anyway. Plenty of info on the web if you are interested.



Geissele SSA-E Trigger

Replacing the stock trigger was a simple affair with the Geissele SSA-E being a drop in unit. We will provide a link to the manufactures website for this trigger so you can have a more detailed read about the trigger and how it works;

To say this trigger is an improvement over the stock trigger is a major under-statement. The trigger is a two stage design with the initial pull being 2.3 pounds followed by an additional second stage pull of 1.2 pounds, giving an overall pull weight of 3.5 pounds. Geissele describes the second stage as having a 'candy-cane' break and we tend to agree. It is crisp and with a short reset allows for faster and more accurate follow up shots. Geissele claims 'The Geissele Super Semi-Automatic Enhanced (SSA-E) Trigger is a finely-tuned semi-automatic-only version of our full-auto, two stage combat trigger presently used in the U.S. Special Operations Community.' 

Hard to argue with that!


Raptor Charging Handle

The stock charging handle performed its role well and we never had any functional issues. After a day of shooting however our fingers were a bit sore and we wished for a more 'meatier' grip when racking the bolt. We settled on the 'Raptor' charging handle made by Rainer Arms. The stand out difference is the handle itself which is larger and provides a more secure grip when pulling the bolt back. The Raptor can also be pulled back utilising either side of the charging handle. This along with the Geissele trigger was one of our favourite modifications to the rifle. 

We have taken a side by side photo of the stock and Raptor charging handles to give you a bit more of an idea.




We have to admit we have not had the pleasure of shooting or playing with a lot of different AR-15 rifles (no thanks to Australian gun laws!). We can not however find fault with the quality of this rifle. Everything works and is rock solid. We have had ZERO malfunctions of any kind and we are satisfied with proper care and maintenance this rifle will provide many decades of trouble free use. With the ease of which parts and accessories can be replaced on this rifle, short of the upper or lower receiver exploding you should never have any issues with replacing minor parts yourself. 



What is there to say other than the Colt LE6920 is a fantastic offering of the AR-15 semi-automatic rifle. It is reliable, versatile, customizable in every aspect, easy to use, easy to clean, easy to disassemble and reassemble. The AR-15 is so customizable is can be difficult to cast criticism at different aspects of the rifle. Why? Well if you don't like something simply replace it! There are thousands of different accessories for this rifle. You could literally end up replacing the entire rifle with aftermarket parts. We would've liked to have seen better accuracy however with further testing from handloads and factory ammunition we are confident this can be an accurate rifle. 

If you are one of the few Australians with the holder of the correct firearms licence you owe it to yourself to at least try one of these rifles. We have enjoyed shooting the LE6920 and will continue to do so for quite some time.




  • So many but we will list them again!
  • Reliable, versatile, easy to maintain and work on
  • Customizable is so many ways. If you can think of an accessory for it chances are it is already on the market.



  • Receiver gets very dirty due to the design of the DI gas system
  • Stock trigger was too heavy with too much creep for our liking
  • Accuracy was not outstanding


Cons (for owning an AR15 in Australia)

  • Difficult to obtain in Australia due to state/territory and import firearm laws
  • Aftermarket support for your rifle in Australia is not going to be great, many AR-15 parts are heavily restricted for import
  • You will discover MANY new shooting 'mates' you never knew you had


Specifications (as listed by Colt)

  • Barrel Length - 16.1 inches
  • Bore - Chromed, 1:7 RH Twist
  • Extended Length - 35.5 inches
  • Collapsed Length - 32 inches
  • Weight - 6.9 pounds


Specifications (as measured by the Buy Used Guns Team)

  • Extended Length - 35.78 inches or 909mm (with CTR stock)
  • Collapsed Length - 32.48 inches or 825mm (With CTR stock)
  • Weight - 9.47 pounds or 4.3 kilograms (with all accessories as pictured and a full 30 round magazine)


You can check out the full line-up of COLT rifles at



In regards to the Remington r15, will thr daniel defense accessories fit this moddl rifle? Will the quad rail fit? Grips and magazine apps be suitable for australian laws and conditions following the d-CLASS specs?
Chers ray

raymond 04-02-2016 03:02AM
Leave a Comment