We’ve mentioned SureFire’s Advanced Rifle Operating Core (AROC) in the past but now it’s in production and has been demonstrated to several customers. There is a great deal of excitement surrounding this new weapon concept. It consists of a new Upper Receiver, including Bolt Carrier Group, as well as Action Spring and Buffer, all of which can be used with existing Lower Receivers.
The AROC bolt lugs are 1/3 longer, making them twice as strong as a standard mil-spec bolt. Naturally, this requires a matching barrel extension. The longer barrel extension reduces the steep feed ramp angle as found on a standard M4, for smoother and more reliable feeding of ammunition.
The AROC Bolt Carrier has an additional .400” of travel into the receiver extension requiring a shorter buffer. Along with the additional bolt carrier travel, there is a spring loaded weight in the rear of the carrier that acts as a counter weight to increase dwell time, reducing the cyclic rate to 590-610 rpm depending on ammunition. This makes the weapon easy to control on full automatic fire, increasing accuracy and effectiveness of the weapon. The AROC’s Bolt also has a set of interlocking Inconel gas rings that never wear out. Known in stand-alone mode as the Optimized Bolt Carrier, it is available as a drop-in accessory for existing AR pattern weapons, but you won’t get all of the advantages of the full AROC.
The AROC also has a heavy duty gas tube to handle full automatic fire. The delayed unlocking of the bolt reduces carbon fouling allowing the AROC to fire thousands of rounds without cleaning or lubrication. That’s right, no lube necessary. All the testing for the AROC was done with no lubrication.
The AROC is available as a Carbine, Designated Marksman Rifle, or a box fed lightweight squad machine gun. It’s a super reliable, very controllable, upper receiver that can be added to an M4 or HK416 lower receiver. The AROC pictured has a 14.5” machine gun, chrome lined barrel. Weight is 7.9 pounds with M4 lower receiver. However, shorter and longer barrel lengths will be available as well. Shown with the SOCOM556-RC-TN contract suppressor.
The AROC will be at The USASOC Sniper Competition held at Range 37, March 22-23. For more info contact SureFire VP of Military Sales, Jamie Wiedeman, jwiedeman@surefire.com.
Tags: Surefire
I’m actually pretty stoked to check these out. Hoping I’ll see an 11.5″ variant sometime in the near future.
So who’s making all the barrels using these proprietary barrel extensions?
If I had to make an educated guess, maybe FN or DD. Can’t imagine they’d take all these steps for a better mouse trap but skimp out on CHF.
Hmmm, seems to me that with a little bit of proper engineering/design, the extension is the only thing you need to change. A regular threaded, ready-to-go barrel could just be torqued in. And even if it is, when you contract for a truckload of barrels, you can include the specs for the new barrel extension which the barrel maker will be screwing on anyway.
Except that the gas port and barrel nut index pin are both drilled and installed at the same time, (usually).
Exactly. Unless surefire releases all the TDPs for free and the industry as a whole gets behind this, it’ll remain a very niche thing and likely very expensive due to the proprietary aspect of it’s barrel extension.
Those gas rings sound interesting. Wonder what it looks like and how it is produced.
It’d be cool to further refine it to minimize wear throughout the system, especially for the complete upper system. Reinforcing the cam pin area like how Colt does it on the LE6940/901 and a replaceable roll pin for the charging handle latch like on the MCX or ZEV billet sets.
i like it but not the fact it’s not parts compatible with the vast majority of other AR’s out there.
Thats the weakness of any new AR upgrades. Agencies can afford to experiment and have trained amours to deal with stuff. The civilian market wants milspec basics. Civilians are more interested in new coatings and metals than owning a totally new lookalike AR rifle system.
KAC selling tons of SR-15s disproves that thought.
Agreed, I’ve been following this BCG as closely as casually possible all over the inter et and I believe leaving the realm of being compatible with 90%+ of rifles out there will limit the chance people will adopt this.
I still want one, but I refuse to get rid of my faxon pencil 14.5″
This is a really exciting development; the OBC/AROC paired with the new URG-I upper + Geissele HSS would make for a great “M4A2” system.
With a 1-6x optic, you’d have a “universal infantry weapon” that could serve as Carbine, DMR, and Automatic Rifle in a single package.
It’s not really needed though.
Just going to a mid length gas system greatly improved bolt life with the URG-I. It surpasses that of the HK416 now.
the carrier and buffer with a normal bolt and barrel extension would probably be a pretty hot ride.
So, is there going to be a way to purchase one of these in semi-auto on the civilian side?