Proof Carbon vs Steel barrels

[Robert N]

All this talk of suppressors has me thinking about lightweight, suppressed hunting rigs with short barrels.

My current suppressed rifle (Let’s call his SRfile for short) is a Rem 700 SPS .308 with the 20” heavy barrel. Screw an 8” can on the end and that’s a long rifle for sure and not exactly a lightweight either, tipping in at nearly 10# full up. Remington also made this rifle with a 16.5” barrel…in retrospect that would be a nice option for full time can use.

This got me thinking about a lighter weight, SRifle for hunting. I suspect a super Skinny barrel is out of the question with a can. But maybe a Proof Research carbon barrel has the stiffness with the weight savings for such a build. I’m thinking target weight of 7.5# scoped with the can in place.

Thoughts?

 

[Elkmagnet]

Sounds like a good plan to me. In fact that's my current plan. I think a carbon fiber barrel is the way to go. Getting you a light weight barrel with a 5/8 thread. I have my gun setup and am waiting for form approval sometime late spring.

 

[pyrotechnic]

Having enough diameter at the muzzle for properly sized threads and looks are pretty much the advantages a carbon fiber barrel has over a skinnier contoured steel barrel. If you are really looking to go as light as possible then a skinny steel tube will win.

I did see a thread somewhere else where a guy had ordered some custom contoured blanks from barlein that had a bell at the end to allow for threading like the Barrett feildcraft, that could be another way to go and cheaper than a carbon wrapped barrel. With both you have to pick your blank based in your desired finish length.

 

[nhenry]

My lightweight rifle build is a carbon fiber rifle. I suspect I could get lighter with a shorter barrel, or a different action, or the Peak 44 stock instead, but mine comes in right at 7.4 lbs scoped (without the cuff).

-blueprinted Rem 700
-Proof Sendero Light 24”
-McMillan Hunter’s Edge Sendero
-Leupold VX-3i 3.5-10x40

 

[Elkmagnet]

Having enough diameter at the muzzle for properly sized threads and looks are pretty much the advantages a carbon fiber barrel has over a skinnier contoured steel barrel. If you are really looking to go as light as possible then a skinny steel tube will win.

People keep saying this but as a guy who has had a few long pencil barrel magnum rifles all of them had groups start to walk after 5 quick shots and some after 3. This gets old sitting around at the range waiting for a barrel to cool.
My cf barrel puts the groups in the same spot regardless of previous shots or temp.
It has been really nice at the shooting bench. I know shot #6 will go where shot #1 went.

 

[nhenry]

People keep saying this but as a guy who has had a few long pencil barrel magnum rifles all of them had groups start to walk after 5 quick shots and some after 3. This gets old sitting around at the range waiting for a barrel to cool.
My cf barrel puts the groups in the same spot regardless of previous shots or temp.
It has been really nice at the shooting bench. I know shot #6 will go where shot #1 went.

This^
People will argue that those pencil barrels weren’t properly made, or the smith messed up, or whatever. Carbon barrels just stay in the same place, simple.

 

[pyrotechnic]

To be honest the only custom barrels I have had spun up have all been Remington varmint contour or greater. I currently have 2 proof carbon barrels that both seem a bit picky, and a bartlein carbon fiber I don't have as much time with. So I can't make any personal claims about long shot strings in light profile barrels

I'm not convinced either way on a whether quality light weight profile barrel will "walk" on longer shot strings due to heat. I do believe that poor barrel will start stringing shots sooner in the lighter profile than that same quality in a heavier one. I also believe that light guns are harder to shoot and manage recoil on, so the shooter starts playing a larger role in stringing as well.

ETA:
To expand on the above. I find it reasonable to ascertain than since there is no such thing as a perfect barrel, that a skinnier profile barrel will drift it's POI at a lower round count than a heavier one of identical quality due to less mass and it heating up faster. What I'm not convinced of, is that the difference is decernable in high quality barrels by even above average shooters.

 

[fishing4sanity]

Shooting suppressed or not comes down to personal preference, I'm a big fan of suppressors. I have two main hunting rifles, both I shoot suppressed. My 300RUM has a steel Benchmark barrel and I use a 5" Thunder Beast Ultra suppressor. My 7 SAUM has a Proof carbon fiber barrel and I use a 7" Thunder Beast Ultra suppressor. @Robert N take a look at some of the shorter cans available and consider those as well. Obviously the shorter can is louder, but both work very well. The 7" can goes on my comp rifle as well, when you're taking a 100+ shots in a day a little more noise reduction is good.

 

[Elkmagnet]

To be honest the only custom barrels I have had spun up have all been Remington varmint contour or greater. I currently have 2 proof carbon barrels that both seem a bit picky, and a bartlein carbon fiber I don't have as much time with. So I can't make any personal claims about long shot strings in light profile barrels

I'm not convinced either way on a whether quality light weight profile barrel will "walk" on longer shot strings due to heat. I do believe that poor barrel will start stringing shots sooner in the lighter profile than that same quality in a heavier one. I also believe that light guns are harder to shoot and manage recoil on, so the shooter starts playing a larger role in stringing as well.

ETA:
To expand on the above. I find it reasonable to ascertain than since there is no such thing as a perfect barrel, that a skinnier profile barrel will drift it's POI at a lower round count than a heavier one of identical quality due to less mass and it heating up faster. What I'm not convinced of, is that the difference is decernable in high quality barrels by even above average shooters.

My sample is admittedly small but I really do believe that the greater the diameter of the barrel the better it will resist change from outside forces like heat and physical deflection. For example will hanging a 16oz weight off the end shift the point of impact more on a lightweight steel or a carbon barrel?
For steel you can use a calculator to check specific barrels of known tensile strength. The most important predator of strength is diameter then tube length then thickness and last material tensile strength (for steel tube).


Here is a calculator that may be used for this purpose but I'm not sure that it crosses over to cf barrels.

Tube Calculator - Round, Rectangular & Square Pipes Capacity | Rogue Fabrication

www.roguefab.com

 

[pyrotechnic]

I think that you're correct, although I would look at th Youngs modulus and the moment of inertia as the mechanical and geometric properties of your barrel that would effect the outcome the most.

What I'm not so sure of is at what point do those differences become decernable. I you have 2 quality barrels, one is a 3lb sporter contour and the other a 3lb carbon wrapped barrel. At what round count in a certain time and at what weight of suppressor do you actually get a benefit? You probably will have an easier time getting the proper threads on your carbon wrapped barrel though.

It would be neat to spin up two high quality barrels, one in like a 2 contour and the other in an mtu contour and shoot long strings with both out of a machine rest. Then repeat the test with a suppressor or even different weights and see what the results would be. To actually have a valid test you'd need more than one of each barrel though.

 

[pyrotechnic]

I'm not shitting on carbon wrapped barrels, I have 3 of them. But a big part of that is being able to thread them properly and still be relatively lightweight. Also, I think they look pretty baller.

 

[Elkmagnet]

I think that you're correct, although I would look at th Youngs modulus and the moment of inertia as the mechanical and geometric properties of your barrel that would effect the outcome the most.

Also whether a carbon barrel has more deterministic vibrations and less random.

 

[Doublecluck]

People keep saying this but as a guy who has had a few long pencil barrel magnum rifles all of them had groups start to walk after 5 quick shots and some after 3. This gets old sitting around at the range waiting for a barrel to cool.
My cf barrel puts the groups in the same spot regardless of previous shots or temp.
It has been really nice at the shooting bench. I know shot #6 will go where shot #1 went.

Agreed, the biggest reason to use a carbon barrel by far.


All the proof barrels both steel and carbon I have shoot great. One day some day the suppressor fairy will approve my applications.

 

[p_ham]

I don't know why anybody would want a suppressed rifle when the '06 Springfield exists!

Honestly, a short carbon barrel is the way to go if you want lightweight suppressed use. 17-18" is just about right for a lot of cartridges. I'd stay at 20" for magnums.

 

[Wind Gypsy]

Having enough diameter at the muzzle for properly sized threads and looks are pretty much the advantages a carbon fiber barrel has over a skinnier contoured steel barrel. If you are really looking to go as light as possible then a skinny steel tube will win.

I did see a thread somewhere else where a guy had ordered some custom contoured blanks from barlein that had a bell at the end to allow for threading like the Barrett feildcraft, that could be another way to go and cheaper than a carbon wrapped barrel. With both you have to pick your blank based in your desired finish length.

^ This is my take on the whole deal. IMO we'd have better options for both performance and cost if the market demand was for normal contours with flared ends for threads ala fieldcraft rather than carbon and fancy fluting that has more potential to impact barrel accuracy. I had krieger make me a custom contour for a 7 SAUM in this way and will likely have a 6.5 ordered similarly once i start thinning out the safe.

People keep saying this but as a guy who has had a few long pencil barrel magnum rifles all of them had groups start to walk after 5 quick shots and some after 3. This gets old sitting around at the range waiting for a barrel to cool.
My cf barrel puts the groups in the same spot regardless of previous shots or temp.
It has been really nice at the shooting bench. I know shot #6 will go where shot #1 went.

Were the pencil barrel magnums you had aftermarket barrels of similar quality to the carbon you're referencing?

Based on Alex wheeler actual measured deflection tests showing a carbon barrel and steel barrel of the same weight where carbon barrel deflected more, I tend to believe there is no benefit to carbon barrels over a steel barrel with a bell on muzzle for threads. I'm open to the idea that this may not be universal amongst all manufacturers as they don't all make carbon barrels the same. The Owner of Bartlein basically stated that there wasn't a benefit to carbon barrels other than there being a market for them.

I have only two carbon barrels, one (HCA) just isn't consistently accurate. The most consistent load i found for it would group tight, AFTER the cold bore shot about a MOA down and to the right of the warm bore group. The Bartlein carbon I have (with more steel in the liner) shoots fantastic.

The other rub with carbons is you are more likely to get a dud than a steel barrel. This seems reasonable because you're dealing with an additional process on a thin steel liner that can induce additional stresses on it that dont exist with a steel barrel.

On short barrels intended for suppressors the weight savings are less because you have % of the barrel covered with carbon between the shank and the steel muzzle portion. You're also more likely to have enough diameter for threads on a standard contour if it's shorter.

 

[LuketheDog]

People keep saying this but as a guy who has had a few long pencil barrel magnum rifles all of them had groups start to walk after 5 quick shots and some after 3. This gets old sitting around at the range waiting for a barrel to cool.
My cf barrel puts the groups in the same spot regardless of previous shots or temp.
It has been really nice at the shooting bench. I know shot #6 will go where shot #1 went.

My .257wby does this. It has a 26" fluted barrel, 3-4 shots and the barrel is HOT and the group starts to open up after that. I've been shooting my carbon barrel 6.5prc alongside as I wait for the .257 to cool, it's barely warm to the touch after the same # of shots.

 

[Robert N]

That’s an interesting question: does the CF insulate the barrel, holding the heat IN?

 

[Elkmagnet]

^ This is my take on the whole deal. IMO we'd have better options for both performance and cost if the market demand was for normal contours with flared ends for threads ala fieldcraft rather than carbon and fancy fluting that has more potential to impact barrel accuracy. I had krieger make me a custom contour for a 7 SAUM in this way and will likely have a 6.5 ordered similarly once i start thinning out the safe.

I view this as a "choose your flavor" I don't believe you would get different results from a fieldcraft to a Savage ultralight.
Honestly grab one of these at 6.1lbs screw a suppressor on and you will likely be shocked how good it is. My son's shoots cloverleafs with every factory ammo I have tried.

Ruger American® Rifle Compact Bolt-Action Rifle Model 16980

ruger.com

Were the pencil barrel magnums you had aftermarket barrels of similar quality to the carbon you're referencing?

They were all factory steel vs a factory carbon.

Based on Alex wheeler actual measured deflection tests showing a carbon barrel and steel barrel of the same weight where carbon barrel deflected more, I tend to believe there is no benefit to carbon barrels over a steel barrel with a bell on muzzle for threads. I'm open to the idea that this may not be universal amongst all manufacturers as they don't all make carbon barrels the same. The Owner of Bartlein basically stated that there wasn't a benefit to carbon barrels other than there being a market for them.

I never did find his video. How was he conducting his test?
The scenario where I see a thin steel barrel deflect is usually pretty consistent.
On a cold day shoot a quick 2-5 shot group at a few hundred yards. Let the barrel cool for just long enough that the very thin muzzle end cools off but the chamber end is still hot lets say 3-4 minutes now shoot one more shot and see where it goes. My friends and I tried it on a few thin steel barrels and they all threw that shot. My carbon and heavy contour steel were far better I assume because they cooled in a more even manner.
This is something that I can see regularly happening in hunting situations/conditions

The other rub with carbons is you are more likely to get a dud than a steel barrel. This seems reasonable because you're dealing with an additional process on a thin steel liner that can induce additional stresses on it that dont exist with a steel barrel.

Seems like a plausible theory my sample is notably small so I couldn't give any thoughts

On short barrels intended for suppressors the weight savings are less because you have % of the barrel covered with carbon between the shank and the steel muzzle portion. You're also more likely to have enough diameter for threads on a standard contour if it's shorter.

Definitely. See ruger american link above.
If suppressors were readily accessible the market would sort this out quickly. We would have many short barrel 5/8" 24 options to choose from.

 

[Elkmagnet]

That’s an interesting question: does the CF insulate the barrel, holding the heat IN?

Possibly but it's also spreading it across a larger area.

 

[Seamaster]

I have been a benchrest shooter for many years competing is a sport where the rifle's weight is important, and I have yet to see a carbon fiber barrel on the line. The competitors in benchrest do everything and anything to gain even a tiny bit of an advantage, and most of them would be screwing on Carbon fiber barrels is there was any hope it would help.

I understand that a hunting rifle with a thin barrel contour is quite different from a benchrest rig with a nice thick tube. To date nothing has proven better than steel for accuracy, but I can see that the carbon barrels are becoming popular with certain types of shooters for whatever reason they have (adding accessories, etc.). However, a standard sporter contour barrel on a hunting rifle is thick enough to thread for accessories, and weighs about the same as the carbon fiber models.