SFAR 6.5 Creedmoor Barrel Length Question. 16"? Opinions?

[jreffner]

Hi Everyone,

So I've waited a year for a 6.5 Creedmoor version of the SFAR, but I want it in 16" or I'd settle for 18", but as most of you know it is only available in 20". Yes, I'm aware I'll lose some performance, and that you will tell me to just get the .308, but I'll take the ballistic hit to get a softer and flatter shooting caliber, AND I don't want to stock yet another caliber. I already have the Ruger Precision in 6.5 CM and nothing chambered in 308. So, please give me your opinion: Do you think Ruger will do a 16" or 18" SFAR in 6.5 CM, or should I just deal with it and get the 20"? Thanks for your thoughts!

 

[hittman]

Welcome to the forum.

 

[Mobuck]

Welcome to the forum.
I have a 20" AR 6.5 Cr and a 22" bolt action 6.5 Cr. A friend has a Ruger bolt action with the 16.5" barrel. There is a significant velocity loss between the 22" and the 16.5". The short barrel drops the velocity into the higher end of 6.5 Grendel 20" barrel range. In addition, the 16.5" is absolutely ear shattering even with ear pro. I can't recommend the shorter barrel for general use or hunting unless you intend to wear ear pro full time while hunting. I don't think you'll find a 16.5" 6.5 Cr is what one would call 'flat shooting' due to the much reduced velocity.
Another consideration is the numerous functional failures of the SFAR in 308 that have been reported.

 

[jreffner]

Mobuck,

Thanks for the information. It won't be used for hunting and ear pro full time isn't a problem, but your velocity report conflicts (or is just a difference in opinion) with two YouTube videos I have seen (yeah, I know….). Either way though, it is pretty clear that you doubt Ruger will even release an SFAR with a shorter barrel. I appreciate the time and effort in your response. Many thanks! Anyone else? I'd appreciate all thoughts and opinions on this.

 

[kmoore]

Chop the barrel and recrown if that's what you want, but can't buy over the counter. It that's what I wanted, I would buy a 20 inch and try it. Then decide if 16 is what I want or think I need. It might help if you posted why you want a 16 inch.
Really 4 inches of barrel when talking 16 to 20 on a carbine is not going to make or break usefulness.

 

[Mobuck]

"Really 4 inches of barrel when talking 16 to 20 on a carbine is not going to make or break usefulness."
At least not for a 'range toy'.

 

[jreffner]

Chop the barrel and recrown if that's what you want, but can't buy over the counter. It that's what I wanted, I would buy a 20 inch and try it. Then decide if 16 is what I want or think I need. It might help if you posted why you want a 16 inch.
Really 4 inches of barrel when talking 16 to 20 on a carbine is not going to make or break usefulness.

I want the 16 inch because it's a lighter. Lighter and smaller. I basically want an AR-10 chambered in 6.5 Creedmoor but having it light is key. It will not be used for hunting. It will just be used for a range toy and hopefully never defense.

 

[jreffner]

"Really 4 inches of barrel when talking 16 to 20 on a carbine is not going to make or break usefulness."
At least not for a 'range toy'.

I agree, and I was quite surprised when I saw two videos on YouTube that tested this very same thing. They were bolt guns in 6.5 CM, but the barrel lengths were 20 inches and 16 inches. In both videos, the 16 even shot fairly well out to 1200 yards. Yes, the velocity was less but I can deal with that for a shorter and lighter rifle.

 

[hittman]

How heavy is 4 inches of a rifle barrel and would it really make a difference?
Especially if you're not packing it through the woods or up a mountain side.

 

[Hvymax]

Hi Everyone,

So I've waited a year for a 6.5 Creedmoor version of the SFAR, but I want it in 16" or I'd settle for 18", but as most of you know it is only available in 20". Yes, I'm aware I'll lose some performance, and that you will tell me to just get the .308, but I'll take the ballistic hit to get a softer and flatter shooting caliber, AND I don't want to stock yet another caliber. I already have the Ruger Precision in 6.5 CM and nothing chambered in 308. So, please give me your opinion: Do you think Ruger will do a 16" or 18" SFAR in 6.5 CM, or should I just deal with it and get the 20"? Thanks for your thoughts!

For that caliber 20-24" would be my minimum. Anything less is wasting powder.

 

[krw]

I agree, and I was quite surprised when I saw two videos on YouTube that tested this very same thing. They were bolt guns in 6.5 CM, but the barrel lengths were 20 inches and 16 inches. In both videos, the 16 even shot fairly well out to 1200 yards. Yes, the velocity was less but I can deal with that for a shorter and lighter rifle.

Don't compare bolt guns to gas operated semi-autos. Buy a chrono. It will be an eye opening learning tool

 

[Mobuck]

"How heavy is 4 inches of a rifle barrel and would it really make a difference?"
Valid point. I'm not sure how heavy the SFAR is but on a full size AR10(ish) rifle, the weight 4" of barrel won't be noticed.
I'm old and not as strong as once was but the AR10 is definitely a 'two hand' platform. With a decent scope and sling, it's a 'pig'. Which is (i assume) the reason for the SFAR platform.
As I mentioned, it's doubtful that cutting a 20" back back to 16" will function. There's just a whole list of things that get out of whack in this scenario.

 

[hittman]

Ruger's spec sheets say ( in 308 ) the 16" SFAR is 8 ounces lighter than the 20 inch.
6.8 pounds vs. 7.3 pounds.

 

[Hvymax]

Why not just get an efficient load for the desired barrel length. Are you trying to light things on fire with the muzzle blast?

 

[jreffner]

Ruger's spec sheets say ( in 308 ) the 16" SFAR is 8 ounces lighter than the 20 inch.
6.8 pounds vs. 7.3 pounds.

yes, but I would say a half a pound is significant. Especially on a rifle that is supposed to be all about weight savings. I'm getting the feeling though that a 16 inch won't be offered. I also agree that cutting the barrel down is very risky as it's probably not gonna work at all. I suppose I could replace the handguard with a carbon fiber handguard on the 20 inch model to save some weight. Again, thank you everyone I appreciate the information and opinions. Feel free to add more.

 

[jreffner]

Don't compare bolt guns to gas operated semi-autos. Buy a chrono. It will be an eye opening learning tool

So please forgive my ignorance, but comparing a bolt gun and a semi auto is a bad idea? At least when dealing with velocity?

 

[krw]

Yes. The auto's are stealing gas to make them cycle. Plus you need to pay more attn to pressure signs with an auto over a bolt rifle. An auto is less forgiving than a bolt rifle

 

[Mobuck]

"So please forgive my ignorance, but comparing a bolt gun and a semi auto is a bad idea? At least when dealing with velocity?"
Not exactly BUT: There's some variation depending on system function. Probably more variance between individual barrels than a specific difference based on bolt or semi action.
I did a quick check on barrel weights for different lengths and found the weight reduction could be in the 4 to 8+ ounce range depending on barrel profile. Keep in mind, the muzzle end is the lightest part of the barrel. A more effective weight reduction would come from a lighter profile barrel toward the chamber end.

"Yes. The auto's are stealing gas to make them cycle."
While it may seem so, consider that the bullet has already exited the muzzle before the AR gas system 'steals' a significant amount of propellant gas. The only gas 'stolen' is the tiny amount required to fill the gas tube but the bolt doesn't move until well after the bullet is downrange. With a piston op system, the amount is even less.
That fireball seen when firing a semi-auto at night is the expulsion of WASTED gas so a wee bit of gas tapped to run the gun is inconsequential, having little to no effect of performance.

 

[kmoore]

Sounds like a project that could start from the ground up. Just build an AR platform with parts that save that 6-8 ounces. Barrel diameter and length might be a start. I have found sometimes what one thinks is the best is not available unless far too much money is invested and maybe compromise is needed. Thers always been the weight vs accuracy vs range vs power vs caliber.

 

[Mobuck]

^^^ Agree. There are several 'made for AR15 platform' cartridges on the market that challenge short barrel 6.5Cr/308 performance. Since this class of cartridge uses the same basic lower/upper as the .223/5.56, cost will be lower and available parts are a snap to access.
Keep in mind that the .308 loses it's long range capabilities as the barrel length is reduced. Back when I was shooting a .308 frequently, a barrel under 24" just wasn't worthwhile. It took that much barrel to get a decent weight bullet up to an adequate velocity. I was shooting Nosler 155 HPBT at fairly conservation velocities to cut recoil a bit and they worked well out to maybe 500. Beyond that, the 155 began to wander in the wind more than the 175-190's and couldn't hold velocity as well. I finally went to a 165-168 bullet with slightly hotter loading and was satisfied with performance out to 500 which was all I needed at the time. This was using a 25" barrel.