Building your own guns is a gas. Nothing quite fills the void the corporate world creates like spending a few hours in the shop driving roll pins and torquing things to spec. Building a gun to meet your particular need is rewarding right up until it isn’t. There’s a point where assembly becomes ‘smithing and that’s right where I draw the line. The beauty of military specifications is that darn near any AR parts will fit together as long as they’re built to the standard. But what if you want more than what the .223/5.56 arena has to offer? . . .
In that case, you’d need to step up to a righteous rifle cartridge. And there’s nothing more American or righteous than a .30 caliber bullet nestled in a case headstamped .308 WIN.
If there’s no replacement for displacement, there’s definitely no getting around the fact that 150+ grains of copper and lead is just more (in every way) than the 55 grains offered by the .223 Remington. To hear some of my fellow People of the Gun tell it, .308 WIN is the end-all be-all of full power rifle cartridges. And if you’re looking to send a couple downrange in rapid succession, the same people might be inclined to tell you that there is no finer rifle system to do that than the AR-10.
Eugene Stoner sure thought so. His first well known foray into rifle design was the AR-10, a svelte, select fire, gas operated rifle capable of utilizing the 7.62×51 cartridge that saw great success with the military in the heady days of the Cold War. While it did well in trials, the M14 won out and became the .30 cal battle rifle of the day. Stoner went on to downsize the design into the M16 and eventually ended up at Knights Armament where he created the SR-25 which was adopted by the US military.
Where the M16 created a standard for the parts used in the commercial AR-15, the AR-10 never saw that kind of adoption and subsequent standardization. As such, creating the big boy rifle of your dreams is harder than it looks. More than likely, the path of least resistance is to buy a complete rifle from any number of the companies. Should you decide that you don’t like some element of that off-the-shelf gun, though, your options to swap or upgrade that part are somewhat limited. Should you elect to build one from scratch, the process is even harder. Not impossible mind you, but more difficult. Brownells set out to make it easier.
Given that the two most “customized” parts of any modern sporting rifle are the hand guard and the butt stock, Brownells teamed up with Aero Precision to offer the 18″ OEM 308 Rifle. At a buck under $1000, the OEM Rifle, a M5 if you’re buying from Aero, ships to your FFL as a “functional” firearm in that it can be loaded and fired. It lacks a buttstock and a hand guard, though. Those are up to you as the end user to select and install, and your wallet is the only limiting factor there.
But that’s where I found the first problem with the concept. There was no direction from the Brownells website on what would and wouldn’t fit this rifle. The marketing team at Brownells told me to pick something out and after poking around a bit, I found a Midwest Industries rail that looked like it would work and added that to the list. Also part on the list were magazines as the OEM Rifle ships without them. I already had a buttstock that would fit the mil spec buffer tube. Should you find yourself without one, anything that will fit a mil spec AR-15 buffer will work.
Rifle in hand, I went to clamp the rail to the barrel nut and realized that the factory nut and Midwest rail were incompatible. The package from Midwest included the proper barrel nut, but I lacked the tooling to swap out a barrel nut on an AR-10 the right way.
With a short deadline, I made due and got the barrel nuts swapped out. Almost immediately I was horrified at the rail/receiver interface. These two just weren’t made for each other. It turns out that there are two different heights for the AR-10. One is the DPMS-style and the other is the Armalite style. Naturally I’d selected the wrong one. For those curious, the Aero guns follow the DPMS specs…I’ll take things I wish I’d known before ordering for $200, Alex.
New hand guard in place, I set off to the range to get the ole gal sighted in and to see what she was made of. Part of that testing included screwing a silencer to the end. Gas operated guns can be finicky beasts and there’s no better way to muck things up than to add a lot more backpressure and carbon to the system.
Out of the gate, the rifle was unreliable at best. Rarely could I get through a magazine without some sort of failure. There never seemed to be a pattern to it, but I got failures to eject, failures to load, and even a couple of cool double feeds. The absolute best was the one you see above where a spent case managed to turn itself around 180° and really shut things down.
Adding a silencer to the mix only made these problems worse. Consider a can-equipped OEM rifle to be crippled completely. What I found in less than 100 rounds was that the gas system wasn’t playing in harmony with the rest of the action. If ever a gun was in need of an adjustable gas block, this has to be it.
Still, I soldiered on thinking that perhaps it was one of those guns that just needed to be broken in. I packed it up along with some spare ammo and headed off to a bachelor party that included some shooting. I’d sent an email the week prior to the guys attending with a list of what I was bringing and what food would be required to turn money into loud noises.
One of the guys was VERY interested in owning an AR-10 so he loaded up on a prodigious amount of .308 WIN for the weekend. I was happy to oblige him as reliability testing is one of our most expensive parts of a gun review. His ammo, his money, and results I could use for TTAG…everybody wins.
On the third magazine of the day, the gun locked right up, refusing to be manipulated in any meaningful way. Luckily I carry tools, and I’m not afraid to beat on other people’s guns. As you can see above, the culprit was a bolt catch that had broken cleanly in half, locking the bolt to the rear with no way to release it.
My only theory on how this came to pass is summed up in the video above. Best I can tell, something in the fire control group didn’t play nice and the repeated falling of the trigger weakened the bolt catch to failure. To be clear, I never dry fired this gun with the upper receiver removed, and the failure point of the bolt catch happened well under the 250 round mark.
At that point, I’d run out of patience and any remaining good vibes. I penned a hateful email to the Brownells marketing team, but sat on it for a few days to see if my thoughtful German heritage might override my Irish need to fight. As has happened so often in the past, the Germans won. I explained the issues I’d had with the hand guard, the reliability issues, and the broken catch. Within minutes, I had an apology from the Brownells team, a UPS call tag, and instructions to return everything that I didn’t put on the gun.
A week later, my FFL called to let me know that a new rifle had arrived. This one had the hand guard already installed and came with a comically large pile of Magpul SR-25 style magazines. With the remaining ammo I had (including quite a bit from a guy at a bachelor party who didn’t get to shoot as much as he’d wanted), I headed back to the range. Firmly ensconced in the bed of my truck with a sturdy Harris bipod and a stack of sandbags, I shot the following groups for score.
As you’d expect, the 1:10 twist barrel really favors the 175 grain Federal Gold Medal, but what rifle doesn’t? The rest of the field was a mixed bag. I could pretty reliably count on the OEM rifle to turn in sub 2.5 MOA performance, but getting sub 1 MOA groups simply never happened. I’ll place a pretty decent amount of the blame on the gritty and garbage-awful stock trigger.
The pull weight is somewhere in the eight pound range with a vague feel for where it might break after slogging through quite a bit of mush to get there. The upside? It never failed to light one off. The downside? Literally everything else about it. I imagine the mechanical accuracy is there to make this into a consistent sub 1.5 MOA or better performer, but in my hands, I was less than pleased with what it brought to the table.
Reliability was much improved in the second rifle I received which I’ve chalked up to the canted gas block you see above. My initial suspicion was that the first rifle was wildly overgassed, and seeing the second rifle purr like a kitten — both with and without a silencer — seemed to add some credence to that theory. As you might imagine, the rotation of the gas block allows for some tuning of the gas flow, though this isn’t a recommended procedure. Again, an adjustable gas block is a must if you’re considering this rifle.
Specifications: Brownells 308 AR OEM Rifle
- Receiver Material: Forged 7075 T6 Aluminum
- Finish: Matte black hard anodized
- Chamber: .308 WIN/7.62x51mm NATO
- Twist: 1:10 Twist
- Profile: Tapered
- Gas System: Rifle length – includes low profile gas block
- Muzzle: Threaded – 5/8-24
- Not included – Magazines, butt stock, hand guard
- MSRP: $999.00
Rating (out of five stars):
Fit, Finish, and Build Quality * *
No issues with any of the coatings on the bolt carrier group or the rifle itself. From the barrel nut backwards, everything seemed to be of a high grade. The receivers fit together well and even include a tensioning screw to fine tune any slop. There are no obvious tooling marks and everything seems to be of top notch construction. Forward of the barrel nut, I encountered a visibly canted gas block and a hand guard that didn’t look like it belonged. Buyer beware that your hand guard of choice very well may not fit.
Reliability * * *
The first rifle would get no more than one star as it not only repeatedly jammed, but ended up breaking the bolt catch. The second rifle I tested fared much better thanks partially to that canted gas block that tuned the pressure. I only had one failure in the 100 or so rounds I put through it and that was a very cheap Russian round that had flown through a silencer.
Customize This *
That one star isn’t exactly fair as this gun is quite customizable. Maybe not as much as the AR-15s that we all love so much, but there’s certainly a lot that can be done here. The one star is pointed straight at Brownells for making the process of matching accessories to this gun a chore. In a day and age where I can go to Ford’s website and build my perfect truck, why can’t I start with a good set of bones and build my dream AR-10 on Brownells’ site? Spare me the frustration and usage of the F-word and show me the SKU’s that will be guaranteed to fit. And finally, be clear about the tooling necessary to do the job. I’m not afraid of a little work to build a rifle so show me the tools I need to do the job right. There’s no reason this can’t be a well executed product. At $999 for the rifle and another $500 or so for the various parts you’d need, plus $100 or so for some tools, this STILL represents a great value for a buyer. The sales guy inside me cries at the lost revenue potential for the company and the gun guy inside is busy beating his head against the wall because nothing fits and nobody told him what tools he’d need to do the job. There’s no reason it should be hard to spend money on a website in 2016.
Accuracy * * *
Decidedly “meh” at ~1.5 MOA with quality ammo, there’s a lot that can be sorted out in the trigger department to improve that. The cheap M4gery stock I installed probably didn’t give me a great cheek weld either. I think the mechanical accuracy is likely there, but it will take the right parts to make it happen. It’s combat effective and not much more out of the box.
Overall * *
This gun has a lot of potential for excellence. I was really excited to get it out in the field for testing and evaluation as I thought it represented a new way to acquire and customize a rifle that wasn’t an AR 15. Brownells is one of my favorite retailers, and one that’s gotten quite a bit of my money over the last few years. I had hoped that this product would wow me, but I can’t shake the bad taste from a missed opportunity. The Aero OEM rifle has good bones, but it doesn’t solve any of the problems it was designed to fix. You still need tools and specialized knowledge that’s not readily available to go out and get a well sorted AR-10 platform gun. Add in the massive reliability and QC issues, and I’m forced to wonder if Brownells or Aero really have their heart in this. If they could solve those issues and create a better buying experience, this could be a real gem. But if the “backorder” status on their webpage is to be believed, maybe they don’t have to. There’s potential here, but as tested, it left me disappointed.