Ruger SFAR 308 first impressions

[budlight]

I'm thinking (OK, hoping?) the 20" Ruger SFAR would shoot just fine with that rifle length gas system - similar to a light bolt action - without that boomer brake. What do ya'll think? I'm not worried about my shoulder - I'm wanting to know how tough to get follow up shots without a brake. Anyone? Thanks!

I just looked the 20 inch SFAR and it appears that Ruger didn't do their home work They put on a mid length gas system. Not rifle length or even better yet rifle length plus 2 inches. Short gas tubes are just a pressure bleed off and they diminish FPS. It also means that the BCG/buffer tube weight gets beat up.

I did some posts about the significant pressure differences from carbine, mid, and rifle length gas port holes. Another factor is gas port hole diameter. You want the longest tube or rod and barrels made with the smallest hole diameter.

Some AR variants can only use service rifle "Low Pressure" rounds NOT full on 308 bolt rifle rounds. It's why I build my own and know what i'm getting

 

[MoGunsBro]

Thanks for the heads up. Sure looks rifle length to me - the gas block is within an inch of the 15" hand guard. I am not an expert and don't build my own.

How many inches is the gas system? I understand Intermediate is around 13.25" and rifle around 15".

 

[Steves1911]

I just looked the 20 inch SFAR and it appears that Ruger didn't do their home work They put on a mid length gas system. Not rifle length or even better yet rifle length plus 2 inches. Short gas tubes are just a pressure bleed off and they diminish FPS. It also means that the BCG/buffer tube weight gets beat up.

I did some posts about the significant pressure differences from carbine, mid, and rifle length gas port holes. Another factor is gas port hole diameter. You want the longest tube or rod and barrels made with the smallest hole diameter.

Some AR variants can only use service rifle "Low Pressure" rounds NOT full on 308 bolt rifle rounds. It's why I build my own and know what i'm getting

The 16" is midlength but the 20" is rifle length. Where did you see the 20" is mid? I can also assure you it runs fine on full power 308 loads on gas setting 2 and it has a pretty heavy buffer spring.

 

[MoGunsBro]

The 16" is midlength but the 20" is rifle length. Where did you see the 20" is mid? I can also assure you it runs fine on full power 308 loads on gas setting 2 and it has a pretty heavy buffer spring.

Thanks Steve for the update. I just bought this rifle and hoping it's not a dud.

 

[budlight]

The 16" is midlength but the 20" is rifle length. Where did you see the 20" is mid? I can also assure you it runs fine on full power 308 loads on gas setting 2 and it has a pretty heavy buffer spring.

Who do you believe?

The Ruger SFAR is available with a 16-inch barrel(link is external) or a 20-inch barrel(link is external); both are cold-hammer forged out of 4140 chrome-moly steel and feature an extremely accurate 5R rifling with a 1:10" twist rate, and a massive Ruger 2-port Boomer muzzle brake installed on to a 5/8"-24 threaded muzzle.



The Ruger SFAR features a mid-length gas system with a 0.750" 4-position rotary-regulator gas block; a chrome-lined 8620 steel bolt carrier and nitride-processed, staked gas key; a DLC-coated titanium firing pin; and CNC-machined bolt and barrel extensions, manufactured out of high-strength super alloy steel that outperforms traditional C158 bolts.

 

[MoGunsBro]

There are two models with two different gas systems.

The 16" SFAR (model # 5610) has a mid length system.

The 20" SFAR (model # 5611) spec sheet:

• The rifle-length gas system features a 0.750" 4-position rotary-regulator gas block to achieve ideal function across the wide range of ammunition available in the marketplace today. The included, on-board 3/16" ball-end wrench makes for easy regulator adjustment.

Ruger® SFAR™ Autoloading Rifle Model 5611

ruger.com

 

[MoGunsBro]

The 16" SFAR (model # 5610) spec sheet:

• The mid-length gas system features a 0.750" 4-position rotary-regulator gas block to achieve ideal function across the wide range of ammunition available in the marketplace today. The included, on-board 3/16" ball-end wrench makes for easy regulator adjustment.

Ruger® SFAR™ Autoloading Rifle Model 5610

ruger.com

 

[budlight]

An example of nato lower pressure 7.62 X 51 that blows the primers and jams with off the shelf 308 rounds. My bud bought one and what a disappointment. To reload for it you had to use service rifle tables.

FN SCAR®-H Mk2 - FN HERSTAL

fnherstal.com

 

[Okanogan]

I ran factory Norma 150 gr FMJ target loads through my 16 inch SFAR with no signs of over pressure with the #2 setting and no suppressor.

I generally find that most of my gas guns, regardless of caliber, tend to show ejector marks sooner than I would expect to see with my bolt guns. My 6.8 SPC in particular shows light marks with factory 120 grain sst ammo. I handload almost all my ammunition and generally never make it to the full max charge weight in my gas guns because I don't like beating up my equipment and components. The reduction isn't usually more than 1-2 grains so it doesn't concern me as long as I can work up a load with good accuracy. The information that came with my GAP10 said specifically not to push the pressures in handloads and that is probably good advice for all gas guns.

While I don't have extended experience with my SFAR, it seemed to perform similar to my other gas guns except that I expect better accuracy from my Craddock Precision uppers and GAP10.

 

[MoGunsBro]

SFAR more likely to cook off rounds than other (larger) 308 semi autos?
The Ruger SFAR manual talks about the Ruger can cook off rounds when the barrel is really hot, and just wondering is that a typical disclaimer that would be true of any proven 308 platform / battle rifle (Sig 716i, FN FAL, M1A, etc.), or if Ruger's thinner chamber cooks off faster than other semi 308s? My primary purpose for this rifle is hunting bear or hogs, and I can't afford shooting 308 as a range toy, but I do want to make sure if I ever send several rounds downrange, this thing isn't significantly MORE likely to cook off rounds than any other 308. Make sense?

"The SFAR™ fires from a closed bolt. Sustained firing can create excessive heat in the barrel and can cause "cook-off" of ammunition (heat-firing of the cartridge in the chamber). This "cook-off" can occur a substantial period of time after firing has ceased. Always unload the firearm and unload the chamber immediately after you have finished shooting." p.18
https://ruger-docs.s3.amazonaws.com/_manuals/sfar.pdf

Thanks!

 

[Okanogan]

You certainly put more effort into reading the SFAR manual than I did, not that it is a bad thing.

I don't know why the SFAR would be any more susceptible to cooking off rounds than any other AR platform, which I think have a relatively low risk of occurrence. I'm not a dump multiple 20/30 round magazines kind of guy but obviously others have done it with other AR platforms, and I have yet to hear any first accounts of cooking off a round in an AR. That doesn't make me an expert though.

I shot 5 round groups at the range in about 2 minutes and then let the SFAR cool with the chamber empty and bolt open. Overheating the barrel is hard on your equipment and not good for accuracy. If nothing else, letting a round sit in a hot chamber for a while is likely to change the powder temperature and have the potential to increase pressure. I think if you use your equipment in any kind of reasonable fashion such as what you've described, you don't have to worry about it. The Ruger instruction to unload the firearm and chamber when you're done shooting sounds like good advice though for a number of reasons.

 

[MoGunsBro]

You certainly put more effort into reading the SFAR manual than I did, not that it is a bad thing.

I don't know why the SFAR would be any more susceptible to cooking off rounds than any other AR platform, which I think have a relatively low risk of occurrence. I'm not a dump multiple 20/30 round magazines kind of guy but obviously others have done it with other AR platforms, and I have yet to hear any first accounts of cooking off a round in an AR. That doesn't make me an expert though.

I shot 5 round groups at the range in about 2 minutes and then let the SFAR cool with the chamber empty and bolt open. Overheating the barrel is hard on your equipment and not good for accuracy. If nothing else, letting a round sit in a hot chamber for a while is likely to change the powder temperature and have the potential to increase pressure. I think if you use your equipment in any kind of reasonable fashion such as what you've described, you don't have to worry about it. The Ruger instruction to unload the firearm and chamber when you're done shooting sounds like good advice though for a number of reasons.

Thanks. The SFAR barrel is heavier than a few other AR 10s (M&P 10) but the chamber (and BCG) are much thinner / lighter.

Likewise, I don't mag dump - but want a gun that could handle it if I ever did.

 

[budlight]

If you are dumb enough to keep firing a weapon after the barrel is hot to touch then you deserve a cook off

Actually I was in the military and carried a selectable fire semi/full auto M-14. Days at the sniper range we shot thousands of rounds. Now a couple of ar10's. I pig hunt and range time. I've shot 30 round mags one after another, but when a rifle gets hot I go to rifle number 2 or even 3. barrels don't last in extreme heat. Never a cook off seen or heard of in my life.

Just like every prescription commercial on TV they cover their ***

 

[MoGunsBro]

brought 20" SFAR home Friday and took to range Saturday - running magpul pro offset (my "backup irons") - haven't yet decided on what scope - so I sighted in my magpuls.
shot it with the boomer brake at 25 and 50 yards - shoots great! Fun as hell.

If I can find my 7/8" wrench I'll remove the brake via jam nut and see how it shouts without the brake. May wait til I get a scope and see how it does long range.