My carbon barrel project so far-- AI AE mk111 308

[joshmartin8]

well guys for those that have followed this project and or have heard about it hear is the final up and running prototype, Accuracy international with 30cal barrel chambered in 308, The original weight of the 26'' barrel was 7.45lbs, after profiling and carbon treatment the finished barrel comes in at 3,52lbs, OVER 50%weight saving,

I have only been out and run the barrel in so far with 40 rounds but the results so far are very promising, more to come very soon

[simonl]

That's a huge weight loss. How was it done?

What was the original barrel profile?

[tackb]

it looks like it's grouping well josh ?

[Ronin]

Whats the radial yield strength of the carbon fibre wrapped barrel compared to a standard CM or Stainless tube ?

 

 

Have you done any pressure tests with for instance plugged barrels (in safe controlled environment)

 

 

Without knowing how much material youve taken off the barrel (how thick the barrel wall is), im not convinced that this is going to be a healthy experience for you...

 

 

Whilst this short video below isnt exactly comparable to where im coming from, im sure you get where my concern comes from....

 

 

 

[joshmartin8]

That's a huge weight loss. How was it done?

What was the original barrel profile?

 

 

the original barrel profile was the same as it is at the muzzle now- 1.2''

[joshmartin8]

That's a huge weight loss. How was it done?

What was the original barrel profile?

 

 

the original barrel profile was the same as it is at the muzzle now- 1.2'' a section of the steel barrel was removed and the reinforced with carbon back to original profile,

[joshmartin8]

Whats the radial yield strength of the carbon fibre wrapped barrel compared to a standard CM or Stainless tube ?

 

 

Have you done any pressure tests with for instance plugged barrels (in safe controlled environment)

 

 

Without knowing how much material youve taken off the barrel (how thick the barrel wall is), im not convinced that this is going to be a healthy experience for you...

 

 

Whilst this short video below isnt exactly comparable to where im coming from, im sure you get where my concern comes from....

 

 

 

 

 

I don't normally bother replying to the nay sayers ronin, but as i am quite passionate about this project and you seem so supportive i thought i would on this occasion.

 

Yes your right the video isn't comparable in the slightest apart from the fact that it proves that carbon reinforced with a carbon matrix is harder than CM steel, so where i have a steel barrel with a radial diameter of a solid 7mm of carbon reinforcing that is is indeed stronger that a standard barrel.

 

We have in testing hit a prototype carbon barrel with a solid steel bar as hard as we physically can and the carbon doesn't only not dent it doesn't even mark. Or transfer any of the impact throughout to the steel. Any one who went to the show this year and tested the carbon bars next to the rifle on the DCR stand could confirm this.

 

As for radial strength around the chamber that you seem so worried about- the chamber area and shortly after are not compromised in anyway shape or form, i do not intend on publishing the finer details in how i reinforce the barrel to aid in hoop strength or longitudinal strength as this is my own design and a lot of R&D and time has gone into this.

 

As a healthy experience goes it handled the test at the proof house with a lot larger charge than i will ever put through it, but I'm sure you knew that. I have not left a barrel liner as thin as you may think. I've even swayed on the side of caution and left the liner thicker than some factory lite barrels in said caliber.

 

anyway thanks for the support as a british gun smith, you would think any new technologies or advancements to give us more options or choices in parts in the uk would be of benefit to us all, but like i have found out myself you will always get the nay sayers and i have learnt myself what opinion to take when it comes to them,

 

regards Josh

[bradders]

If it's worth saying, it's worth saying twice, and Josh you've done just that

[visiter1]

mighty job mate well done , and i dont see how if a barrel no matter if its made from tissue or bluetack that makes it throuh the proof house can be seen as nothing but safe look forward to more from you mate and best of look n th future .

[joshmartin8]

Out again doing more testing of the C2 precision 308, 10 shot strings, 20shot fast string to build heat,then followed by a 3 shot slow group when hot then 3 shot group once it was cooled, then few more 5shot groups, then to finish the last 7shots of the day to make a group that fits in a 5 pence piece this rifle is proving to be very pleasing. It can shot better than me that's for sure wind was blowing gusts from 5-10mph,

 

[Montey]

As some one who is allways interested in a light waight stalking rifle ( my 308 was built by Dolphin Guns and comes in at just over 7bls ) I'm pleased to see this interesting development in barrel R&D.

At what range was the group testing done ?

Are you intending too market this barrel to other smiths?

I've heard of other people trying to do what your doing and the results haven't been impressive these have been USA company's were I understand they have a Lott of back yard barrel company's as well as the really big high end company's good on you for taking the time and money to get a product to market.

[joshmartin8]

As some one who is allways interested in a light waight stalking rifle ( my 308 was built by Dolphin Guns and comes in at just over 7bls ) I'm pleased to see this interesting development in barrel R&D.

At what range was the group testing done ?

Are you intending too market this barrel to other smiths?

I've heard of other people trying to do what your doing and the results haven't been impressive these have been USA company's were I understand they have a Lott of back yard barrel company's as well as the really big high end company's good on you for taking the time and money to get a product to market.o0]['?;.

 

thanks montey,

the testing was completed at 100 yards for this test, i have since done some load dev testing at 200 and the results are also very pleasing. 1inch groups happily at 200.

Yes i am indeed planning to market this and supply to the trade. before i do i am intending to build a lightweight stalking rifle, say 20inch,varmint profile in 260, but as light as i can and test the barrel in that platform, once that has been put through its paces then i will look to get them made to the trade.

[varminter]

 

thanks montey,

the testing was completed at 100 yards for this test, i have since done some load dev testing at 200 and the results are also very pleasing. 1inch groups happily at 200.

Yes i am indeed planning to market this and supply to the trade. before i do i am intending to build a lightweight stalking rifle, say 20inch,varmint profile in 260, but as light as i can and test the barrel in that platform, once that has been put through its paces then i will look to get them made to the trade.

Nice to have someone local making and hopefully supplying to the trade!!!

Shall watch with interest and thanks for your efforts and posting!!!

[joshmartin8]

Got out yesterday and tried finding a final load with some development with 155 amax and 155 scenar, they had different point of impact slightly, scenar's go left and amax go right, funny that, but consistent at least. this testing was done at 200 yards this time and apart from the one round stepping just outside the inch mark i was very impressed. with a little bit of seating depth alterations i think i will be finished with development, Put another 50 rounds through her and she is settling down very well now indeed.

 

 

 

 

 

 

 

[terryh]

Josh,

 

Interesting! I'm all for lightening the load (no pun! )

 

One question nags me with anything like this, 'strength' is not an issue but resistance to the environment it lives in is.

 

Things like prolonged exposure to UV or even the chemicals found in rifle cleaning products.

 

What has been done or are you doing related to this type of risk or mechanism?

 

Terry

[joshmartin8]

Josh,

 

Interesting! I'm all for lightening the load (no pun! )

 

One question nags me with anything like this, 'strength' is not an issue but resistance to the environment it lives in is.

 

Things like prolonged exposure to UV or even the chemicals found in rifle cleaning products.

 

What has been done or are you doing related to this type of risk or mechanism?

 

Terry

 

 

good thoughts terry and every input that might be constructive or any issues that people might be thinking about are always worth answering or at least thinking about. The resin content used in the carbon process is UV stable, Chemical resistant and very very hard wearing, smashed the hell out of two demo barrels and i physically cannot dent the carbon or damage it. seen and verified by many people now,

 

Your just round the corner from me terry if you fancy having a look and a play !

[Will0]

What kind of price will these be compared to a normal barrel? Also, will they be available to fit the large chassis AXMC, which needs quite a hefty profile by the action

[Ronin]

 

 

I don't normally bother replying to the nay sayers ronin, but as i am quite passionate about this project and you seem so supportive i thought i would on this occasion.

 

Yes your right the video isn't comparable in the slightest apart from the fact that it proves that carbon reinforced with a carbon matrix is harder than CM steel, so where i have a steel barrel with a radial diameter of a solid 7mm of carbon reinforcing that is is indeed stronger that a standard barrel.

 

We have in testing hit a prototype carbon barrel with a solid steel bar as hard as we physically can and the carbon doesn't only not dent it doesn't even mark. Or transfer any of the impact throughout to the steel. Any one who went to the show this year and tested the carbon bars next to the rifle on the DCR stand could confirm this.

 

As for radial strength around the chamber that you seem so worried about- the chamber area and shortly after are not compromised in anyway shape or form, i do not intend on publishing the finer details in how i reinforce the barrel to aid in hoop strength or longitudinal strength as this is my own design and a lot of R&D and time has gone into this.

 

As a healthy experience goes it handled the test at the proof house with a lot larger charge than i will ever put through it, but I'm sure you knew that. I have not left a barrel liner as thin as you may think. I've even swayed on the side of caution and left the liner thicker than some factory lite barrels in said caliber.

 

anyway thanks for the support as a british gun smith, you would think any new technologies or advancements to give us more options or choices in parts in the uk would be of benefit to us all, but like i have found out myself you will always get the nay sayers and i have learnt myself what opinion to take when it comes to them,

 

regards Josh

 

 

 

 

Josh

 

 

I am not a "nay sayer", ive no idea who you are or what your experience is behind this tech.

 

My question was formed from looking at previous carbon wrapped barrel manufactuerers wares and looking at the results of comparative strength tests such is the one I posted - I couldnt find anything about radial yield strength.

 

Its obviously a concern to anyone using a lightened barrel - you made no reference to barrel wall thickness being the same as a proprietary ightweight unit either - so in essence your barrel is a featherweight or lightweight sporter dressed in carbon wrap to emulate a medium palma profile or similar....

 

You mention the barrel passing proof, this wasnt something mentioned in the OP.

 

I asked about pressure tests, meaning cup pressure analysis and burst tests using plugged barrels - again the question was asked from the aspect of YOUR and any other users safety.

 

As a part time rifle builder, I would look to use this technology if available in the UK and if asked by a customer - I would certainly not recommend using that technology without knowing that its safe, tried and tested.

 

(on that note simply "hitting a barrel with a steel bar as hard as we can" doesnt cut the mustard for me)

 

Im all for innovation and am interested in your results.

[MJR]

Hi Josh,

 

a couple of observations. The first groups shot at 100yds, you have with the exception of one shot to the right a fairly consistent centred fall of shot. Subsequent groups appear to move to the right of centre. I know you said the shots were taken in 5-10mph cross wind but I wouldn't expect the 5mph difference to make more than 0.1mil difference on poi so are you confident the barrel is not walking the groups off to the right as it warms up?

Secondly what environmental testing are you doing, I'm thinking along the lines of salt bath testing etc. I know the carbon to steel bond will be good but what are the different expansion rates and will the bond remain stable after a thousand or so heat cycles?

Interesting project.

[Gandy]

Is the carbon applied prior or post the machining process or are there areas left at the end of the barrel blank to do this.

[lambsey]

Very very nice

[joshmartin8]

What kind of price will these be compared to a normal barrel? Also, will they be available to fit the large chassis AXMC, which needs quite a hefty profile by the action

 

 

once they go to market their retail price will be published.

[MJR]

Any update on how the testing is going? Did you try more groups to see if the poi is walking right?

Do you intend pluging a test barrel and destruction testing?

[Grum87]

Perhaps showing my ignorance, but what do plugged barrel testing and blowing to bits show? Surely most if not all barrels would fail in such a test?

[MJR]

No not necessarily and if it does fail you can see the mode of failure and how intact the carbon wrap stays or does it become shrapnel?

I'm genuinely interested in the project and doing such tests demonstrates due diligence should someone have an issue later down the road.