Gun Review: Colt LE901 16S

Even with a rifle as modular as an AR-15, there is still one big decision to be made. Namely, do you want to go the AR-15 route (with the smaller, intermediate 5.56 size magazine well) or the AR-10 route (with the full .308 size magazine well). That decision will dictate what uppers you can buy, what magazines you can use and a whole host of other things. But what if you didn’t have to make that decision? What if you could buy one rifle that used both AR-15 and AR-10 mags and upper receivers? That’s the whole idea behind the Colt LE901 16S . . .

We saw the LE 901 at the SHOT Show this year, where they demonstrated the gun’s ability to swap pretty easily from one set of upper receivers to the other. So we can check the box that it works as advertised. But thanks to the same system that allows the swap in the first place, you’re pretty much stuck with the .308 upper that comes with it.

The reason has to do with two features: the bolt design and the takedown pin placement.

LE 901 bolt, c Nick Leghorn

The bolt face and forward section of the LE 901 is identical to the one on a standard AR-10 rifle. But in order for the rifle do its magic trick, the back of the bolt carrier (the part that slides into the buffer tube) needs to be the same diameter as the AR-15’s. In other words, smaller. An AR-10 bolt will fit, but the gun won’t cycle. That’s because the LE 901 uses the same buffer tube dimensions as the standard AR-15 instead of the larger AR-10 buffer tubes.

You’d think that the smaller rear section would lead to some tilting on the part of the bolt, but because the diameter of the bolt carrier is the same as the buffer tube, life is good. The bolt carrier is almost immediately captured by the buffer tube, and comes straight back.

Unfortunately, this means that any AR-10 style upper receiver you throw on the gun will need the specially shaped bolt carrier. However, thanks to the next feature, not every AR-10 upper will work.

The distance between the takedown pins is longer for the AR-10 and shorter for the AR-15. In order to get everything to line up, the AR-15 uppers need to use an adapter (which didn’t appear to be included with the gun). The adapter grabs onto the AR-15 upper’s forward takedown pin, and then slots into the magazine well. That way, it not only adapts the upper for the longer takedown pins used in an AR-10, but also shrinks the mag well so that AR-15 magazines will fit snugly.

The result of that arrangement is that the forward takedown pin needs to be moved. Specifically, it’s lower than normal by about half an inch. That means the only upper receiver that will fit the thing is the one designed specifically for this firearm by Colt. That’s a pretty big drawback if you bought the LE901 expecting a gun that’s 100% compatible with both platforms.

The good news, however, is that the upper receiver checks all of the usual boxes. It ships with a monolithic upper that sports full-length rails on all sides and comes with ladder style rail covers already attached. The gun has a set of iron sights where the front is permanently attached but the rear is detachable. They feel pretty solid, and they seem to work quite well, so no complaints there. The only problem I have is that the charging handle sucks. Then again the charging handle always sucks when it’s the standard design.

The barrel is a standard 16-inch variety with a pronged flash hider attached. The end user can crank that sucker off and replace it with whatever they want instead, as the prongs have a tendency to vibrate and sound like an annoying tuning fork.

LE 901, c Nick Leghorn

The lower is pretty nifty as well. The controls are almost fully ambidextrous — the safety selector is still one-sided, and you can’t lock the bolt back except with the ping pong paddle. But the bolt release and magazine release can be operated from either side.

The trigger, on the other hand, really sucks. Like all “mil spec” triggers, it’s in that unholy area where it’s not crisp enough to be a single stage trigger, but doesn’t have the smooth first stage to make it a two stage trigger. It’ really fairly awful, and a replacement trigger should be your first modification when you bring this rifle home. There are much better triggers out there, and the wonder of the AR platform is that you can swap out parts until you’re happy.

The real test of the gun, though, is how well it shoots. And I give the LE901 a resounding “meh.”

In terms of reliability, there’s not a whole lot to recommend it. After soaking the damned thing in CLP, I couldn’t get it to run reliably. I’d get about three rounds downrange before I had a failure to feed from the magazine and needed to yank on the charging handle. Annoying on the range, infuriating on a hunt and downright scary in a life-or-death situation.

We know, however, that the gun runs. We saw it run at SHOT Show, and we’ve been hearing good reports. So I’m pretty happy diagnosing this as a fluke. I get the feeling that a lighter buffer spring would fix it, but I didn’t have one on hand and shortening the one I had wasn’t an option.

Accuracy was similarly “meh.” The best I could manage was a 1-inch group at 50 yards (so…2 MoA), which then quickly widened out to an 8 MoA 5-round group. There was some left to right crosswind (more of a cross breeze), but I’m guessing the fact that the rounds started walking to the left means that wind wasn’t the issue.

In short, what we have here is an okay gun. It works, but it’s not very accurate and the trigger pretty much sucks. These are both problems that can be fixed though, and given the unique properties of the rifle, it would still make me stop and think before I paid for a dedicated AR-10 platform. In the modular world of the AR platform, this certainly does kick things up a notch.

The Colt LE901 16S for this review was provide by The Kentucky Gun Company.


Caliber: .308 Winchester
Sights: flip-up iron
Barrel Length: 16.1″ heavy profile
Weight: 9.4 lbs
Capacity: 20 round PMags
Price: $2,599

Ratings (out of five stars):

Style * * * * *
It looks pretty darn good, with all the expected design features.

Ergonomics (firing) * * *
The gun feels okay, but the trigger is terrible.

Reliability * * *
It looks like the LE901 needs some work to make it cycle reliably. It ran fine at the SHOT Show Media day shoot, but I couldn’t get it to cycle reliably. I’m guessing it just needs a little TLC.

Customize This * * * * *
Not only is this as customizable as a standard AR-10, you also get the ability to swap calibers between the AR-10 and AR-15 platform. Which is really nifty, and opens up all sorts of options.

Overall * * *
It’s an okay gun. The shortcomings in terms of ergonomics are more than compensated for by the nifty features. However, if everything worked right out of the box, this would easily become my #1 “under $3,000” recommendation.