This is a video on the basic assembly/dissasembly of the Colt 901 Modular Carbine
The Colt LE901-16S, known simply as the 901, at first look appears to be just a new .308 version of the standard Colt AR-15. But after hearing that it was multi-caliber capable since back at SHOT of 2011, we finally got to see how it actually does that and actually get the gun running. Called a Modular Carbine, the Colt 901 is truly a new invention.
Colt sent us #126 and though we’d love to keep it, it will be traveling to the next reviewer soon I’m sure.
The Colt 901 swaps calibers with this aluminum part that weighs 3 ounces and comes with its own captured pin. You fit it into the standard lug on your standard AR upper (we used a Colt 6940 upper) and your .308 carbine just became a 5.56, 6.8 or whatever carbine.
The aluminum adapter slips down into the .308 magazine well and closes up in the gun with the normal crosspin on the 901. It basically moves the lug over on a standard upper to fit the pin on the 901 lower.
Removing the recoil buffer thingy and spring is easy. You just push down this pin and they pop out. Then you just push the new one in and click. The gun is ready to rock.
The ergonomics and usability of the Colt 901 lower are nearly identical to what you are used to on a standard AR. With the .308 upper the gun weighs just over 9 pounds empty and balances right at the front of the mag well. The 901 lower itself is only 9.5 ounces heavier than the Colt 6940 lower.
A standard 30 round .223/5.56 mag looks a little off sitting in the .308 magwell, but it works perfectly and is tight and secure in the adapter part.
This is a top view of two standard AR mags in both the 901 lower with the conversion part and the Colt 6940 lower. They present exactly the same.
We tested both uppers with Hornady Superformance in .308 for the 901 and .223 for the 6940 upper. The optic was the same Leapers Swat scope, which held zero on the individual uppers perfectly, and actually shot to point of aim when you swapped them back and forth. Apparently the tolerances at Colt are pretty tight these days.
This approximately 1.5″ group at 100 yards was fairly repeatable with the optic in the .308. The trigger was a scratchy on this lower and probably not the trigger they will ship with.
The 6940 upper with the adapter shot 2″ or under, note quite as good as we tested it on the 6940 lower, but the scratchy trigger probably had something to do with it.
The barrel and bolt carrier on the 901, like the other Colt Carbines, are marked Colt magnetic particle inspected.
The quad rail on the Colt 901 has two holes in it for these proprietary sling studs that go on with like an aircraft fitting. This gives you a viable option for single or two point mounting. These come as part of the goody pack you get with all the new Colts. It has two mags, a cleaning kit, rail covers, the sling swivels, and the manual.
This left hand magazine release is great if you actually want to retain the empty magazine rather than drop it on the ground. You can release and pull very easily at the same time, and keep your finger ready at the trigger.
Colt Manufacturing Company LLC
Never underestimate a legend, and that legend is Colt. At first glance you would think that the Colt 901 is just a .308 Win./7.62 NATO version of a standard AR-15, much like any other .308 AR out there, but it is a lot more than that. The Colt LE901-16S is a “Modular Carbine,” which means it can be adapted to any AR-15 platform upper. This isn’t a new concept, because there are of course a whole bunch of different caliber uppers for ARs. The difference is in all the other ones, they have adapted a standard size AR magazine to boutique calibers and cartridge designs. The Colt 901 is different. It can be adapted from .308/7.62, using standard P-Mags, to .223/5.56, using standard AR mags, and back again, in literally seconds. The design uses one proprietary part, and you have to swap out the recoil system. It is that simple, and it works fantastic.
We have read in many places that the Colt 901 is actually for sale, but we have yet not seen it in the market. Our gun is numbered #126 and did not arrive in consumer packaging. The MSRP, which on the Colt 2012 official retail price list includes tax, is $2,129. This, we assume, will come with the .308 upper, the Colt “goody pack” (which is shipping with all Colt Carbines), that includes 2 mags, a basic cleaning kit, sling, sling studs, rail covers and the manual, and you would think they will include the conversion part, which is the key to the whole system (see the pictures). It may also come with the recoil buffer plug and spring for .223/5.56, we don’t know. Since we already had a Colt 6940 on hand to use as the .223/5.56 upper, we were sent the 901 with its goody pack and the conversion part and the recoil spring and buffer separately.
The key to the whole Colt 901 system is insanely simple. Side by side, the Colt .308/7.62 upper on the 901 and the .223/5.56 upper from the 6940 aren’t that different. Visibly, there is just a small variance in the placement of the forward attachment lug, and of course the size of the magazine well. Someone at Colt most likely was testing the physical dynamics of a .308/7.62 prototype on a CADCAM program and said “hey wait a minute why can’t we just do this.” Then they did just that. And what they did was to design a very simple part that adapts both the lug and the magazine size from one size upper to the other. The part itself is made from aluminum, and weighs exactly 3 ounces, including the captured steel push pin. It is simply an adapter, and its genius is in its simplicity.
Colt AR-15 uppers are standard mil-spec, like any other uppers, so their proprietary 901 lower fits any existing .223/5.56 sized AR upper, using the conversion part. There is of course no such thing as a mil-spec lower in .308/7.62, but from an ergonomic standpoint, the Colt 901 is about as close as you get to what you are used to in a standard AR. Our test rifle weighs 145.4 ounces with the empty plastic P-Mag in it, which is only just a hair over 9 pounds, even with a quad-rail monolithic upper and the fancy Magpul stock. The 901 lower with the Colt 6940 upper and the conversion part and empty steel 30 round mag weighed 121.4 ounces, or just over 7.5 pounds, and only 9.5 ounces more than the same 6940 upper on its own lower with its own slightly less beefy Magpul stock. The 901 is decidedly not front heavy for a .308 and balances on your finger almost exactly at the front of the magazine well with a full 20 round magazine of .308 (approx. 18oz. extra).
The forward assist on the Colt 901 is exactly where you are used to it, unlike some of the other .308 rifles on the market. And besides the mag release button in its normal location, there is a really nifty release lever on the left side of the receiver for one handed mag changes when you want to pocket the magazine instead of dropping it on the floor. The opens sights are Colt manufacture. They both flip down and the front is barrel mounted. The rear is a Colt Defense marked rail mounted. The quad rail has two sling mount points, and in the goody bag are two sling attachments that fit the rail holes with ball bearing mounts. The barrel and bolt on these and all the Colt carbines are magnetic particle inspected and stamped as such. The .308 barrel on the Colt 901 is marked 1 in 12 twist.
This system was obviously made for military and police use, and I predict that it is going to be a big hit among police armorers as soon as it reaches the market. The old .223 vs. .308 argument has been raging since the M-16/AR-15 made its way into battle, beating out the M14, and continues to this day. The .223 as a round is light and you can carry a lot of it. The AR-15 rifle itself is light, around 7 pounds, and in concert they are a formidable battle implement. But since our wars have left the jungle and entered the desert, the .223 has taken a beating for its long range capabilities, as well as barrier penetration, and it is thought that the .308/7.62 NATO in the ideal round to bridge the gap. Different types of missions need different approaches to your rifle and ammo. Sometimes carrying a lot of an adequate round is preferable to less rounds of a more substantial caliber, and vice versa.
This is a huge development that Colt, a major military and police contractor, has nothing short of invented a solution for assault teams and even infantry in the field to the old .223 vs. .308 controversy and it will be interesting to see if it takes hold. I am sure that all branches of the military and just about every police department in the land is going to be looking hard at the 901 as a the next choice of battle rifle. It is an armorers dream come true to have a rifle that can fill nearly every combat role with a nearly identical parts list between rifles, and the AR platform has been proving itself as the basis for such a system for several decades now.
As a consumer rifle, I guess the question has to be, “why do I need it?” The answer is as old as the advent of different firearm calibers for different tasks. The .223/5.56 is at the end of its limit for deer, hogs, and other medium to large North American game. It also is notorious for not being able to keep chugging hard after hitting even a small tree branch. Whatever a .223 hits first is not going to be very happy, but after that, it doesn’t have much left. For smaller game however, and as just a general utility round, the .223 has a lot of fans and has become as popular as a cartridge can be in the US. On the home defense and armchair tactical side, between the light guns and extremely low recoil of the AR-15/.223 combination, nothing has even come close to it in sales over the last five to ten years. Still, though, almost everyone who owns a .223 wishes they had a .308 at their disposal. The Colt 901 isn’t that much more expensive than a high end consumer AR. It is an extremely handy rifle, and it is going to hold its value far more than any off the shelf AR from any other brand, simply because it is a Colt.
Our test rifle is apparently only the 126th made and didn’t even come in a Colt box, so it definitely isn’t a ready for prime time consumer gun. The big thing we wanted to test was of course the caliber swap back and forth, and it worked flawlessly in dozens of cycles back and forth. We hope to have a video up with this soon that shows just how easily the 901 comes apart and goes back together in another caliber. If this gun didn’t have to go back to Colt (grrr) we would do some follow up with other uppers from other manufacturers, and we’d like to try a 6.8SPC upper in as well. For now though, the accuracy testing we did put the Colt 901 through was well within acceptable parameters for a .308 battle rifle. It did seem to throw a flyer here and there, but generally 1.5″ groups at 100 yards were easily repeatable with careful shooting using high powered optics. Our gun had a pretty scratchy trigger, probably not the trigger they will ship with judging by the 6920 and 6940 rifles we already tested. With a better trigger the rifle probably would have shot even better.
The overall idea for Colt 901 is simple and brilliant, and well executed. With all the guns out there, and a lot of guns we really love out there, it is hard to say this, but HALT, if you are about to buy especially a high end AR platform rifle. As you may have read on the comments from readers on the last Colt article who were already Colt owners, now that America’s most notorious firearms company is back in the consumer market, word is getting around that the Colt rifles work great, and that they are accurate and extremely durable. This Colt 901 has some new parts for sure. It isn’t the same bolt carrier and both the .308 upper and lower are new territory for Colt. But it took them a long time to bring this gun to market and they are most likely tooled up to produce government level orders for the 901. It doesn’t smell experimental to anyone who has gotten to know our #126. The Colt 901 is most likely here to stay, and if you can get your hands on one, the 901 is probably making history right under our noses. Never underestimate a legend, and that legend is Colt Firearms.