Why CAN'T I Use Carbon Fiber?

[Ghost Tracker]

My Volquartsen Superlite (M.O.A. Ruger 10/22 Clone) uses a Carbon Fiber sleeve around a stainless inner-barrel to apply "tension" along its length via a threaded muzzle cap. While I've followed various threads on this forum about ideas for a Mini 14 sleeved/tensioned barrel I've never found carbon fiber used as a sleeve material. Why not?

Carbon fiber is heat-resistant, rigid, strong, lightweight, corrosion-proof, and is currently being used in several centerfire barrel applications (not just .22 lr).

The evidence strongly suggests that tensioned barrels improve rifle accuracy. I'm not 100% SURE (is anyone SURE?) what causes this improvement; harmonic dampening, resistance to "whip", minimizing heat related stress factors, etc. Who cares? To me, the why & how is just theory. The actual improvement is the reward.

I have easy access to all the machining equipment necessary. Carbon Fiber tubing & rod stock is readily available. Does anyone have a reason why I shouldn't try the sleeving techniques already developed by forum members using this material?

By the way...this is the BEST gun forum on the web. Thanks for all the help!

[snaz567]

My Clark Custom Barrel Stabalizer uses a very small amount of Carbon Fiber along the muzzle end to reduce weight. I'm not sure why they didn't use more.

[magnomark]

;) Check out the ar-15 thread here,Snaz567 has one posted in a pic in "my toys",looks to be a custom build mini with a short fat carbon fiber bbl;)

[rutro]

Hey Mark, yeah that apeares to be the new Clark Custom Barrel Stabalizer. It works like my little tensioned barrel job more or less. You can see the two holes in the end of the muzzle where the spaner wrench pins fit into it so that you can increase the torque putting more tension or less if you want on the barrel. On mine the A1 flash hider is the part that tensions the barrel and I use a 6'' cressent type spaner wrench. So far I've just settled for about 8-10ft.lbs. of torque and now if I ever kick this dang "Texas lung-eating flu" I might even go to the range again. Warning; ANYONE even thinking of comeing to the Lone Star State right now .......... don't unless you have had your flu shot and all vaxcinations. This is the nasty-est flu bug I've ever wittnessed and it just galloped on through this state and never slowed down, like wildfire and it's been putting fairly young healthy people down and in the hosp.

Anyway back on toppic... Ghost Tracker the only problem I can see is the crush factor. I'm useing steel that is basicly a thinwall tube but it has a pretty high stregnth for what I use it for. The only carbon fiber tube I have experiance with is for fishing poles and we use some surf rods that are pretty special. I've got two 10' and one 11' and they don't weigh anything. But they are stout. I guess if you could use a lathe and turn a stainless barrel down and then roll your own so to speak you might be able to build it up enough so you could torque it down and make it hold up to the recoil. I know that some of the thermoset resins available now are harder than a Preachers pecker on Saturday night ....... that makes diamonds pale in comparison. I'd say go for it if ya got the tools and the time, it's hard to mess one up if you've got the know how and the want to both working for ya, these little barrels do need a little help and we'd love to see a new way ;)

[cne411]

ABS will make you a carbon fiber barrel for about any thing you want. The 2 downsides are price and wait time. My last barrel from them was 8 months and cost $600.

http://home.alltel.net/mdegerness/index.htm

[Ghost Tracker]

I'm one of the principles of a very interesting company. We built Inspection Tooling (gages) & Assembly Tooling (fixtures) for the automotive & aircraft industries. So, I've got easy access to CAD Stations (with Designers to run them), CNC Machining Cells & Lathes (with Machinists to run them), Coordinate Measuring Machines (with Quality Technicans to run them), Urethane Lab, Automation Controls Lab, etc., etc...so finding some +.75" solid Carbon Fiber rod and having it line-bored to just over the diameter of a Mini 14 barrel shouldn't be a major issue. The resulting thick-wall (+ .125") will certainly address any "crush" concerns at the torque levels we're talking about (8-10 ft. lbs., Thanks Rutro! Hope you feel better real soon, we had a NASTY respiratory flu sweep thru the Bluegrass this Winter & I missed three consectutive sick days for the first time in 15 years. My lungs felt like concrete!). Make stainless end-caps with the O/D of the tubing & I/D of the barrel (maybe use the same grade of stainless that Ruger uses for the barrel to match the heat expansion rate). Pin the rear one just past the gas-block. Female thread the front one to match male threading turned at the barrel's muzzle end. Tighten the front cap to tension the barrel. Tune to "ideal" torque (maybe accuracy test with an oscilloscope and look for minimizing vibration frequency?). Sounds like a fun little project & a damn sight cheaper than the Clark Stabalizer if all it costs me is a foot of C/F rod and some stainless raw stock. It shouldn't weight more than a few ounces if I keep the end-caps as light as possible.

Come on boys...y'all have been at this Mini 14 stuff longer than I have. What am I missing?

[rutro]

I don't think you've missed a thing ......... there ain't nothing to it but to do it with the toys you've got!!!!! Just let us see it too, sounds like the kind of plan that WILL work.;)

[johng52]

I'm one of the principles of a very interesting company. We built Inspection Tooling (gages) & Assembly Tooling (fixtures) for the automotive & aircraft industries. So, I've got easy access to CAD Stations (with Designers to run them), CNC Machining Cells & Lathes (with Machinists to run them), Coordinate Measuring Machines (with Quality Technicans to run them), Urethane Lab, Automation Controls Lab, etc., etc...so finding some +.75" solid Carbon Fiber rod and having it line-bored to just over the diameter of a Mini 14 barrel shouldn't be a major issue. The resulting thick-wall (+ .125") will certainly address any "crush" concerns at the torque levels we're talking about (8-10 ft. lbs., Thanks Rutro! Hope you feel better real soon, we had a NASTY respiratory flu sweep thru the Bluegrass this Winter & I missed three consectutive sick days for the first time in 15 years. My lungs felt like concrete!). Make stainless end-caps with the O/D of the tubing & I/D of the barrel (maybe use the same grade of stainless that Ruger uses for the barrel to match the heat expansion rate). Pin the rear one just past the gas-block. Female thread the front one to match male threading turned at the barrel's muzzle end. Tighten the front cap to tension the barrel. Tune to "ideal" torque (maybe accuracy test with an oscilloscope and look for minimizing vibration frequency?). Sounds like a fun little project & a damn sight cheaper than the Clark Stabalizer if all it costs me is a foot of C/F rod and some stainless raw stock. It shouldn't weight more than a few ounces if I keep the end-caps as light as possible.

Come on boys...y'all have been at this Mini 14 stuff longer than I have. What am I missing?

If you need a field tester let me know.:D

[NavArch]

attaching the rear end fitting directly to the gas block. My thought is that you would then be interfacing the carbon tensioner to a natural "hard point" on the barrel. As you are no doubt aware, the carbon tube improves the accuracy of the Mini by changing the vibration pattern of the barrel. As the barrel tries to bend in any given direction, the carbon's high resistance to tensile strain on the opposite side of the barrel will resist motion in that direction. The opposite then happens as the cycle reverses itself. So, I'm thinking that if you anchor the aft end of the shroud to a stronger point, you should impove the results.

How are you going to mate the carbon to the two end sleeves? Will epoxy be strong enough, or will you need to also thread the carbon for a mechanical attachment as well?

With the after end of the sleeve fixed n place, how will you tension the sleeve without imparting any torsional load on it?

[Ghost Tracker]

NavArch,
Imagine: a 6" bolt w/ accompanying nut, two washers and a 5.5" pipe (the pipe is bigger I.D. than the bolt & smaller O.D. than the washers). I put a washer on the bolt and slide it to the bolt-head. I then slide the pipe on the bolt. I put the other washer on the bolt & then screw on the nut. If I hold the bolt-head still & continue to tighten the nut...eventually I reach the point where the bolt is being "stretched" (tensioned) by each twist of the nut because the washers won't allow the bolt-head and the nut to get any closer together.

The nut is the barrel. The pipe is the Carbon Fiber. The washers are end-caps. I can't epoxy the C/F to the end caps, I need free spin. There'll also be no torsional load on the C/F, only compression (like the pipe) preventing the tightening of the forward end-cap getting any closer to the rearward end-cap. That compression corresponds to a tensioning of the barrel.

All this made me thing of something else. Is there any way this forum could support an "All Members" AutoCad system? Drawing some of our ideas would be VERY cool!