Ruger’s New SFAR: A Big Surprise In A Small Package

in AR-15, Authors, Gun Reviews, Mike Dickerson, Misc., Rifles

The new Small-Frame Autoloading Rifle from Ruger packs AR-10 punch into an AR-15 frame

Ruger’s New SFAR: A Big Surprise In A Small Package
The new SFAR, chambered for 308 Win., weighs just 7.3 pounds with a heavy profile 20-inch barrel and even less with a 16-inch barrel.

AR-10 rifles have been around in one form or another for more than 60 years. With a beefier frame and bolt carrier group than its AR-15 sibling, the AR-10 has been chambered for many potent hunting cartridges, with the most popular being the 308 Win. While these guns have experienced varying levels of popularity over the years, they have always had one factor working against them – they are heavy, with most guns weighing 8-10 pounds empty with no optic or mount attached. Cutting weight often meant chopping down barrels, sacrificing velocity, or resorting to using pencil-thin barrels.

Ruger’s SFAR is a Better AR10

Ruger’s new SFAR (Small Frame Autoloading Rifle), chambered in 308 Win., profoundly changes that equation. This new rifle weighs just 6.8 pounds with a heavy profile 16-inch barrel and 7.3 pounds with a same-profile 20-inch barrel. That puts the SFAR on par with many bolt-action rifles in terms of weight. Ruger’s engineers didn’t get there by doing what others have attempted in the past. Rather, they started from scratch with the goal of creating the lightest, strongest, and most affordable AR platform they could create that could handle the higher pressures generated by the 308 Win.

Ruger’s New SFAR: A Big Surprise In A Small Package
The author put the SFAR through its paces at the range and was pleasantly surprised by its accuracy and relatively mild recoil.

They succeeded admirably, and it’s obvious at a glance that Ruger has trimmed weight from just about everywhere it was possible and prudent to do so while adding strength in critical areas. The result is an AR-10 that’s scaled to AR-15 dimensions. There are a few other light AR-10 rifles out there, but this is the smallest and lightest I’ve ever worked with that offers all of the SFAR’s well-designed features at an affordable price.   

Ruger’s SFAR for Hunting or Self Defense

If you want to hunt big game with an AR, the SFAR may be the answer to your prayers. It’s easy to look at this rifle and conclude that it was built primarily for hunters, but it also has obvious self-defense applications when you consider that the rifle has surprisingly mild recoil, enabling you to run it about as fast as you can run an AR-15.

Ruger’s New SFAR: A Big Surprise In A Small Package
The scaled-down receiver dimensions of the SFAR are much closer to those of an AR-15 than an AR-10, but the trigger assembly has been moved rearward to accommodate a 308 Win. magazine

Features of the Ruger SFAR

With other attempts to create lightweight AR-10s, a persistent issue has been durability when manufacturers used traditional AR-15 bolt carrier groups. Ruger designed a BCG that works and will withstand the hammering from 308 Win. ammo. This bolt carrier assembly looks nothing like a traditional AR-10 BCG. It actually looks much like an AR15 BCG, but it’s not. With a chrome-lined 8620 steel bolt carrier, the bolt and barrel extensions are machined from a special alloy with a high nickel content for extra strength and durability. A titanium firing pin has a physical vapor deposition coating for long service life, and the staked gas key is nitride processed. The bolt has dual ejectors and a beefy extractor to ensure positive case extraction and ejection through an enlarged ejection port. Notably, there are venting ports in the bolt carrier, upper receiver, and barrel extension to safely direct excess gas away from the shooter.

Ruger’s New SFAR: A Big Surprise In A Small Package
A rotary, four-position gas block allows you to tune performance to a chosen load.

SFAR Gas Block and Barrel

The test gun sent to me, with a 20-inch barrel, has a rifle-length gas system with an adjustable rotary gas block that has four settings. Setting 1 is for shooting suppressed while setting 2 is for normal use. Setting 3 is fully open, and setting 0 is the off or single-shot position. The rifle arrives from the factory with the gas block adjusted to setting 3. Ruger recommends dialing it to 2 for most uses after a 100-round break-in process. The rifle’s ejection pattern varies with the gas block setting. At 1, brass ejects slightly to the rear. At setting 2, brass goes out at a slight forward angle, and at setting 3, ejection is at a bit more of a forward angle. The gas block adjustment tool is cleverly stowed in a padded compartment within the pistol grip. Guns with shorter, 16-inch barrels have a mid-length gas system.

Ruger’s New SFAR: A Big Surprise In A Small Package
Ruger’s two-port “Boomer” muzzle brake does an excellent job of taming recoil.

Cold hammer-forged barrels are made from 4140 chrome molly steel and have a black nitride protective finish. Each HBAR-type barrel has 5R rifling with a 1:10 rate of twist, and muzzles are threaded (5/8-24) for use with muzzle brakes, flash hiders, and suppressors. The rifle comes equipped with Ruger’s two-port Boomer muzzle brake, which worked like a charm.  I was pleasantly surprised at how well it tamed recoil.

Ruger’s New SFAR: A Big Surprise In A Small Package
Attention to detail, such as this generously flared magazine well, is evident in this rifle.

Upper Receiver

The rifle’s upper receiver, forged from 7075-T6 hard-coat anodized aluminum, has a brass deflector, forward assist, and full-length Picatinny rail (rifles with 16-inch barrels have two separate Picatinny rail sections). The lower receiver has the usual controls in the usual locations, along with a generously flared magazine well. Although the design and dimensions of the upper and lower receivers are unique, that doesn’t mean you can’t mix things up. The rifle is compatible with mil-spec MSR trigger groups, charging handles, pistol grips, adjustable stocks, and receiver end plates. The gun comes with one 20-round Magpul PMAG magazine but is compatible with AR-10 pattern 308Win./7.62 NATO magazines.

Ruger’s New SFAR: A Big Surprise In A Small Package
Ruger’s Elite 452 trigger, a two-stage design, broke crisply at a pull weight of 3 pounds, 8 ounces.

Furniture is also from Magpul, including a MOE SL stock and MOE grip. Up front, you’ll find a light, slender 15-inch free-floated aluminum handguard that has M-LOK accessory attachment points at the 3, 6, and 9 o’clock positions. The rifle has a multitude of QD sling attachment points, including an additional QD socket in the receiver end plate.

SFAR Trigger is Excellent!!

Another pleasant surprise was just how good the trigger is on this gun. Ruger calls it their Elite 452 trigger, and while it is not a high-end aftermarket trigger, it is light years ahead of most factory AR triggers. This one is a two-stage design that has a short initial take-up before it stacks and breaks crisply. Ruger says the trigger is set to break at a pull weight of 4.5 pounds, but the trigger on my test gun broke cleanly at an average pull weight of 3 pounds, 8 ounces. Equipped with this trigger, the rifle is ready to hunt out of the box with the addition of an optic (the rifle has no sights).

Ruger’s New SFAR: A Big Surprise In A Small Package
The SFAR comes equipped with Magpul furniture, including this MOE SL stock.

Accuracy and Function testing the Ruger SFAR

For range testing, I mounted a Leupold Mark 4 4.5-15x50mm scope, which is one of my favorites for testing ARs. I chose to test four different hunting loads, versus match loads, to see how the SFAR could perform in the field. Bullet weights ranged from 150 grains to 178 grains. There were no surprises when I ran the four different loads over my CED M2 chronograph. Velocities ranged from 100 fps to 200 fps slower than factory-advertised numbers, but that was expected with a 20-inch barrel.

Functionally, everything worked as it should, but I quickly discovered that the rifle preferred some loads over others. I experienced a few failures to feed with one 150-grain load. The issue was limited to that specific load, and I had no problems with the others. I switched to a different 150-grain load and experienced no more failures to feed.. After range testing was completed, I again shot the problematic load while experimenting with different settings on the adjustable gas block, and that seemed to cure the problem. It’s worth noting that the gun had not yet completed Ruger’s recommended 100-round break-in procedure.

Ruger’s New SFAR: A Big Surprise In A Small Package
Each rifle is provided with a 20-round Magpul magazine.

Accuracy testing confirmed that the rifle liked some loads better than others. It wasn’t terribly fond of one 165-grain load, which produced average groups measuring more than two inches. That proved to be the exception. Hornady’s 150-grain American Whitetail load turned in the best single group, measuring 0.66 inches, and an average group size of 1.10 inches. Federal’s new 175-grain Terminal Ascent load produced the best average group size, measuring just 1.03 inches, with a best group of 0.71 inches. Hornady’s 178-grain ELD-X Precision Hunter load also shot quite well, with a best group of 0.85 inches and average groups measuring 1.14 inches.

Ruger’s New SFAR: A Big Surprise In A Small Package
Groups like this were typical with three of four tested 308 Win. hunting loads.

Match ammo would likely have resulted in some even tighter groups, but I would be perfectly happy hunting with three of the four loads tested. Any time I can get an AR to shoot MOA groups with hunting ammo, I’ll happily take it.

Downsides of the Ruger SFAR

If I had to find anything to fault in this rifle, it might be the relatively small charging handle, which takes quite a bit of force to operate due to the gun’s necessarily stiff recoil or buffer spring, but that’s just nitpicking on my part. You can easily change the charging handle for one with a more substantial grip.

Ruger’s New SFAR: A Big Surprise In A Small Package
The rifle is equipped with a light, slender aluminum handguard with M-Lok attachment points at the 3, 6, and 9 o’clock positions.


All things considered, Ruger’s engineers have done a remarkable job with this rifle, which can take almost any North American game. It will obviously do a good job on deer-sized game, and my first thought upon shooting the rifle was that it is absolutely a hog hunter’s dream.

Of course, this is a new design, and how well it will hold up with heavy or sustained use remains to be seen, but I wouldn’t bet against Ruger considering how well this gun is engineered. The best news: Compared to many AR10 rifles, this one is affordable. It has an MSRP of $1,229 and a street price below that.

Ruger’s New SFAR: A Big Surprise In A Small Package
Ruger’s goal with the SFAR was to create the lightest, strongest, and most affordable AR platform they could design to handle the higher pressures generated by the 308 Win.


Caliber: 308 Win.

Action: Direct-impingement semi-auto

Sights: None, Picatinny rail for optics

Magazine: Detachable Magpul

Capacity: 20

Barrel: 20-inch heavy profile, threaded

Rate of twist: 1:10

Stock: Magpul MOE SL

Handguard: 15-inch aluminum M-Lok

Trigger: Ruger Elite 452

Weight: 7.3 pounds

Length: 38 – 41.25 inches

MSRP: $1,229.00


Competitive Edge Dynamics

Federal Premium Ammunition

Hornady Ammunition

Leupold Optics

Nagel’s Gun Shop

Ruger Firearms

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