The new Small-Frame Autoloading Rifle from Ruger packs AR-10 punch into an AR-15 frame
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.
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.
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.
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.
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.
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.
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).
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.
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.
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.
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.
SPECIFICATIONS: Ruger SFAR
Caliber: 308 Win.
Action: Direct-impingement semi-auto
Sights: None, Picatinny rail for optics
Magazine: Detachable Magpul
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
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I have to agree with the author regarding the charging handle. I just ordered a BCM handle, at an added $75 cost. Be prepared for the added cost of magazines, at $20 each. This rifle is sleek and truly the size of an AR15. I never bought an old school AR10 due to the large size and large price. Steet price locally is $1070, while it now lists at $1329.
The .308 doesn’t generate pressures higher than the 5.56mm. The 7.62mm runs at 50,000 Copper Units of Pressure (CUP). That matches 60,000 Pounds Per Square Inch (PSI) as recorded by modern test methods. The .308 runs at 60,000 PSI when tested with modern equipment. 5.56mm often runs at 63,000 PSI.
The .308 doesn’t produce higher pressures. The 7.62x51mm NATO runs at 50,000 CUP (Copper Units of Pressure) and the .308 produces 60.000 PSI (Pounds per Square Inch) measured electronically. The now obsolescent CUP method confuses people. 50,000 CUP equals 60,000 PSI. .308 and 7.62mm both run at 60,000 PSI. The CUP method is not used in modern ballistics labs.
I believe the author made the comment about .308 pressure vis a vis the pressure of .223/5.56 cartridges that most AR platforms are chambered for.
5.56mm runs at a higher pressure than 7.62mm.
I’m surprised at how just about every gun “riter” I ve read on this rifle fails to mention the POF Rogue which is actually 5.9 pounds. It would also be nice if Ruger would tip their hat to the boys at POF for coming up with the idea for an AR-10 built on an AR-15 upper and lower with enlarged mag well and enlarged ejection port and a little magic with the bolt.
Exactly. Frank over at POF-USA, (God rest his soul), was a true innovator. And for Ruger to drive a 100 miles down the road to buy one. Then reverse engineer it and call it new, is total chickenshit.
I’ve own several POF’s and they are top of the line. And always have been.
Good article. Interesting weapon. The price is very good. Don’t know where MTD gets his parts but at his $700 range I doubt it would shoot that well. I am completing an AR-10 build at this time. Getting the parts that I wanted as they went on sale, I still have over $1100 in the gun. My other AR-10 was built for me and the cost was over $1500 and it doesn’t have the features this gun has. For the features, Magpul stock and grip, adjustable gas block, and muzzle brake, this seems like a great way to get into an AR-10.
>”Don’t know where MTD gets his parts”
mtd may just happen to be a troll. look at some of his other posts
You can build this rifle for about $700.00. Plenty of options out there and have it just like you want it. File this article under “nothing new”.
I wish my AR10 was this light. It is about 2.5 lbs heavier and cost about the same. But unless Ruger sells California compliant versions, this will not be available to me. I am surprised they are sold with a 20 round mag. 10 is more than enough for hunting with this caliber (or similar short action cartridges).
Just about every state has a 5 round mag limit on semi auto rifles.
really? i’m not familiar with that. i’ve got 10s, 20s, 30s. what is this “just about every state”? what state is that?
Check your state’s HUNTING regulations. The common five-round limit refers to what you’re ‘permitted’ to use while afield. You will, however, find numerous exceptions.