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

[bradders]

Very interesting that all the questions about "yield strength" etc are coming from the Mod staff here

What's the motivation behind this?

[joshmartin8]

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.

 

 

 

yes I'm happy they are not walking at all i am going to be waiting for a wind free day or as perfect as i can to do more testing but i have been out once more since then and it was fine, that day just had a strong wind and i think i clicked across a couple clickes as i didn't want the shots blowing out my aiming point on my targets also if i remember rightly,

[joshmartin8]

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.

 

it is applied prior to the chambering/machining,

[joshmartin8]

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.

 

at the mo MJR i am not going to be doing 100% destruction testing as i don't want to risk one of my actions being blown up just for the cause

[ds1]

Very interesting that all the questions about "yield strength" etc are coming from the Mod staff here

What's the motivation behind this?

 

Safety.

 

The mods who are questing it are gunsmiths. I guess that they are interested in using the product as much as everyone else. I can understand being cautious after using a carbon barrel (Christisen Arms?) which left a lot to be desired . So knowing a new product is significantly different seems to be good all around...........makes more sense to ask about yield strength than saying that it looks pretty.

[joshmartin8]

bit late updating the latest set of testing and load development results but here it is, it was all done at 200yards and along a hedge line blocking a fair percentage of wind, the loads were hot loads of n140 with 155 scenars and 155 amax. both bullets are very similar in performance but very strangely they both have a completely different POI . very consistent but still a good way off same POI. she has now had 150 rounds down her and settled down very nicely now. went out and check zeroed the 243 rugger too

 

 

 

 

 

[joshmartin8]

after the last lot of testing last week i know i can't ask for much better results than an inch at 200 yards in field conditions so I'm fairly happy with its load dev now but i am going to try some new bullets my local shop got in for me just for shits and giggles. 168 TMK's i have loved the TMK in all my other rifles so i thought why not give these a try also. got to give them a 90' jump if i make them mag length but wow they certainly look the part. they are sat next to a 155amax for comparison. let you all know how i get on with them on the next chapter,

 

 

 

 

[Ronin]

Very interesting that all the questions about "yield strength" etc are coming from the Mod staff here

What's the motivation behind this?

 

 

 

Safety,,,,, that should be apparent

[bradders]

 

 

 

Safety,,,,, that should be apparent

 

Well have you ever asked Sassen to do a burst or destruction test on one of their ultralight barrels?

Or any other Mfr come to think of it?

 

As for the other person who answered my question, only one of the Mods is a gunsmith, that is unless Terry and MJR have recently acquired their RFDs and some machinery

 

I await enlightenment...

[Ronin]

Is there any reason you have named Sassen in particular

 

 

I dont use ultralight barrels and never will, the point I am making and Im really surprised that individuals are taking a defensive stance when it comes to human life,,, is do these barrels stand up to testing?

 

I am all in favour of new technology, but if there isnt proven scientific testing to say whats being done to the original barrel is safe then I for one wouldnt be using that product.

 

I dont want to know any "trade secrets", but Id like to see what happend if the barrel was plugged and shot - where or if it would fail, if the fail was at a point where the wrapping has occurred - along the re formed section or at each end....

 

Hence my question about yield strength and pressure tests.

 

 

Regarding the other mods, you are way off base too both are very experienced engineers in their fields.

[tackb]

I wish josh well , I met him at the RRC and have no doubt that he will exercise due diligence with these carbon fibre wrapped barrels

With the difficulty of getting stuff from the states I think we should encourage British developments

[Shuggy]

I am all in favour of new technology, but if there isnt proven scientific testing to say whats being done to the original barrel is safe then I for one wouldnt be using that product.

Um....proof test?

[brown dog]

Um....proof test?

 

Have to say, that'd be my view of it too. The bar is set at 'pass proof', isn't it?

[bradders]

Is there any reason you have named Sassen in particular

 

Regarding the other mods, you are way off base too both are very experienced engineers in their fields.

 

1) First name that came to mind

2) Read this "The mods who are questing it are gunsmiths"

 

​Is mods not plural of Mod? referring to there being more than one?

 

 

I know they are experienced in their field, so you're the one that's "way off base here Buckeroo, because while I may just be a poor Irish immigrant that came here on the banana boat, me mammy and me daddy did manage to install a good grasp of the Queens English old boy

 

Like many things, reading is fundamental

[brown dog]

 

1) First name that came to mind

2) Read this "The mods who are questing it are gunsmiths"

 

​Is mods not plural of Mod? referring to there being more than one?

 

 

I know they are experienced in their field, so you're the one that's "way off base here Buckeroo, because while I may just be a poor Irish immigrant that came here on the banana boat, me mammy and me daddy did manage to install a good grasp of the Queens English old boy

 

Like many things, reading is fundamental

 

[MJR]

I say Bradders old boy is the IBS playing up again or is it the orcdacity of a non rfd asking pertinent safety questions that's making you itchy?

 

Back to the original thread. I genuinely hope Josh brings a good safe product to the market and I wish him well. Sure if a barrel passes proof it passes proof, happy days. However barrels do fail in use and that's not a reflection of the barrel but could be from being plugged with mud, a squib round or a reloader making a mistake and over charging or using the wrong powder thereby causing serious over pressure and leading to a failure. I asked josh about testing because there is another material being used on the barrel and I'd be interested to know what happens to the carbon wrap in the event of a barrel failure, does it remain bonded to the barrel, does it splinter etc. I also asked what environmental testing josh intends doing. Bonding high quality resin impregnated carbon weave is usually very successful but I'd like to know what happens when several thousand heat cycles occur between two materials of different thermal expansion. Does the bond remain stable? Does the carbon wrap hold heat in the barrel steel and accelerate throat erosion?

[Ronin]

Think ill be looking at these chaps if they become available in the UK after the limited answers and defensive stance taken....

 

 

 

http://proofresearch.com/the-proof/inside-proof/

[bradders]

I say Bradders old boy is the IBS playing up again or is it the orcdacity of a non rfd asking pertinent safety questions that's making you itchy?

 

Not art all, I just thought it curious the exact same line of questioning suddenly started appearing from the same quarter.

It made no difference whether or not you were or weren't a RFD, it was the bloke from the Czech Republic that spun that yarn.

 

Anyway I digress, I have no interest in these, don't know whether they're good or bad or whatever, and also assume they won't be cheap.

But I have spent a lifetime being curious and questioning things when I think I smell something fishy.

 

Enjoy your thread and evening, I'm in the middle of fixing the lathe....but that's another story

[Mik Mak]

I have fitted several of these, they are CNC cut rifled and shoot fabulously :-)

 

Choice of US Special Forces and have a lot of success in US

 

They will be avail in UK early 2017 off the shelf :-) ???

 

Mik

[Dan534]

Josh, looks like an interesting project and I enjoyed reading the report, lots of work has gone into it clearly and thank for the write up.

 

You mentioned the impact tests which as we all know are a realistic eventuality on a tactical and hunting rifle and composite barrels are clearly strong and stiff enough when in good condition. Ive always wondered how these composite barrels stand up to BVID (barely visible impact damage) which I know is a big concern in the aerospace and aviation sector?

 

Would be interesting to see one thats been knocked around for several months.

 

Keep us posted.

[Big Al]

A friend of mine owns a high tech composite company that manufactures in carbon fibre and other exotics, they have been heavily involved in F1 since the Senna crash back in 1994.

 

I know that they could calculate the strength that was lost by removing the metal aspect from the barrel and that they could also calculate the grade of carbon fibre and the appropriate resin matrix to replace or even improve the strength that was lost. Personally Im not a big fan of the idea and so far the load development results wouldn't inspire me to rush out and buy one but if the composite work has been done properly (which I would expect/hope has been) then strength/safety shouldn't be an issue.

 

Im sure many of us have shot groups half that size with factory rifles and reloads so my advice would be to strive for better groups, otherwise without proven accuracy its dead in the water regardless of its other properties.

[Ronin]

I have fitted several of these, they are CNC cut rifled and shoot fabulously :-)

 

Choice of US Special Forces and have a lot of success in US

 

They will be avail in UK early 2017 off the shelf :-) ???

 

Mik

 

 

 

 

This is the Proof Reasearch range of products, Very interesting!!

[onehole]

A question,,,anyone really please ,,,there seems to be a lot of interest in this carbon wrap barrel and ultimately it will become available as a proven product but do we particularly need this "complication" or have I missed the point of it all,,,,I applaud all the work gone into development by the way,,,,,,,O

[joshmartin8]

well guys as this project moves forward, and i would like to state that until this PROJECT for myself has been fully tested in ways that me and my smith are truly happy that every reasonable testing has been completed to test for accuracy, consistency, ruggedness, durability and many many shooting cycles it will not be made available to anyone to purchase. so for all of you who are worried about safety please only worry about me

 

As far as destruction testing and radial strength testing to failure goes - No i am not willing to blow up a barrel and an action by plugging the end of it on a gun i work very hard to pay for. so that test will have to wait for now sorry if i disappoint.

 

for all those who are genuinely interested and thank you for the appreciative posts for how much work has gone into this so far i will carry on to update and document my findings, as far as accuracy and group testing goes- i know my shooting might not be the best in standards but at the min 1 inch at 200yards in field conditions on a windy day is more than good enough for me..

 

regards to all

 

josh,

 

no hard feeling on this subject now please its an interesting project and I'm enjoying every step of it.

 

ps - expect good things to come from the latest build, will be a very lightweight stalking rifle in standard varmint profile barrel.

[lapua]

Think how dangerous this puppy is... How many failure modes?