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Code of practice for Composite Stocks.

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ozeboy
ozeboy's picture
Code of practice for Composite Stocks.

No!! there isn't one and that is areal problem for anyone wanting to buy a new stock. If it feels OK and has a finish that makes you wet your pants or have an orgasm then it must be a good stock. Unfortunately for the buyer the things that make the difference can't be seen. Listed here are are some of the unseen variables, Is the resin polyester, vinylester or epoxy, What type of carbon or reinforcing is used, crowfoot , twill, plain weave or one of the uni's . What weight reinforcements are used ?, eg. Four layers of 200 gram equals 800 grams in a certain section. Is anyone interested????

chrisjon65
chrisjon65's picture
Stocks

Every stock builder has them own ideas and I am one of them .
But it’s simple really and no need to complicate it .
You build a stock , go to the range . It rides the bag perfectly , returns to aim when pushed back, is bedded and glued in correctly and shoots small groups regularly In hot or cold weather looks good and a shooter loves it who needs a code of practice.

Michael Huebner
Michael Huebner's picture
Stocks

Bruce, Not sure code of practice is the correct term to be used here.
However if you made stocks and explained the advantages of one construction method or material to the next and they ride the bags straight and shoot tiny groups I am sure they will sell.

It is a bit of an art form to get stocks well built, track true and look really good and be in the correct weight range.

My opinion is the Scoville Stocks back when I purchased mine met the required criteria and have served me well over the last 15yrs. (Track straight, 20 - 22oz and look good)

I know you are well aware how to make a stock so I guess why the statement? Are you going to make some some more stocks? Or have you noticed certain things with some stocks? Whether this is on current or older ones.

I am ready and waiting to here what you have to say

Michael

ozeboy
ozeboy's picture
code stocks.

I started this to help a would be purchaser to choose a stock knowing what the construction is.so performance can be accessed. There are some wonderful USA designs and finishes as mentioned the popular Schoville, but the interiors remains a secret. I can guess it's made from various timber pieces, the hardest under the action and covered with 200 grams of Twill carbon. If that was the case then the code would go something like this , Tim-E-200gmTwill C.
having the manufacturers fall into line and support a code would be the hardest part. It has been accomplished with other plastics, flexible polyester and esters. Take the foam cushion you are probably sitting on right now, L19-130 would last a month ,then . N 23-130, H 35-130 HR42-130 progressing to the longer lasting and more expensive. Manufacturers are eager to have a swing tag on the lounges showing how fantastic their lounges are.

No Michael! I'm not building any more stocks, only for myself and occasional friends. I have developed dermatitis due to epoxies and after I make a stock My rists and face itch for three weeks. Due to changes along the way I have ended up with a difficult system and need to rob a bank to pay for all the carbon I use. I was a tech at one of the largest plastic manufacturers in the southern hemisphere. The Lab enabled testing of just about every plastic in use at the time. Came time to retire and I lost access to the company Lab,.

I'll try to answer all questions not covered so far. I have never approached stock building as a means to make money. It's always been an experiment with lab tests, then going out and shooting them.. It's been disappointing that no one has asked me to make a stock giving some details as to construction,so have come to the conclusion no shooters has a clue, hence the topic. Lightest stock made so far is 9 ozs and heaviest 3lb 2 ozs. I can make a stock just about every way others make them but have been using a system that enables the use of difficult reinforcements like 600 grams of 200 gram double bias and unidirectional. I don't use woven carbons at all now and still get the resin to reinforce ratio down to a little over 50 to 55 %. The aim is still to make the lightest ' strongest stocks that will keep point of impact despite less than perfect shooting technique.

Would still like to see a code to help the stock purchasers.

..

mushroom

Michael Huebner
Michael Huebner's picture
Scoville Stock Construction

This is about all you will find on the construction description of a Scoville

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Rabbitz
Killing Innovation

I have no dog in this fight as I am not a stock maker nor an administrator, but isn't one of the foundations of all precision shooting to 'push the envelope' and to innovate?

To create new ideas and methods to improve accuracy and reliability?

So why on earth would you want to prescribe how stock makers go about building their stocks? Why stifle innovation?

I would have thought that the very idea would be anathema to creating the next great breakthrough.

wally289
wally289's picture
stocks

First up your word Anathema WoW I had to look it up surface to say not nice !! leave that there I am not sure us new shooters need a Code of sorts just some honest comments and findings I must say even sometimes you are driven by price I found a stock maker and happen to think there of great quality and workmanship end result strong straight and I might add rides bags well if I had anything to say about them it would be the fore end the bottom edges are a bit Sharpe an angle and can get caught under the lip of front bag ears making it difficult to lift free of rest I’m speaking of T R M stocks dam good product at a good price maybe this sort of thing comment as with all new sports this applies to them all there is top end stuff worth lots of $$$ middle of the road and lower end it just comes down to the reports and choices made from these reports we read and what we’re all looking for in the products my thought’s i think Robs ider of ask a hall of fame shooter is a worthy one IE if you ask about stocks then i would hope the replies would be meney and the new shooter can make further inquiries based on the information he or she gets one thing i have found in this sport if you ask questions you will get answers it's up to the shooter then to make an informed decision

Wally

Wombat

robbycar
robbycar's picture
I don't think that is Bruce's intent

My reading of this is so shooters know exactly what they are buying, not to tell stock makers how to build them.

Rob.

BB Administrator

chrisjon65
chrisjon65's picture
Stocks

I understand someone who builds stocks and understands the processes and materials etc would be interested in the technical side of the making.
I have managed to develop my own take on building stocks and I highlight “My take”
As a Carpenter/joiner/ cabinet maker for 40 years I have come to understand timber and the gluing ,bonding , seasoning ,moisture levels Etc of how to use them.
What any stock maker has to do is understand everyone has read dozens of forum articles etc on who makes the best stocks ,out of what and How they do it .
If you went and cut up any of the suppose it best stocks in the world and they will be all very different .
Any Compeditor who wins a major competition with a particular stock automatically assume his maker is the best .
Give that stock to another known successful shooter he could say it’s no good for him or her.
What goes into making great stocks is the builders personal research development trial and error.
To me that’s a secret that makes his stocks personal to him or her and if a shooter wins with one of those stocks well that’s all one needs .

ozeboy
ozeboy's picture
Composite stocks

Thanks Rob, that's exactly what my intention was, I'm a bit more inquisitive than some and want to know exactly what I'm buying. When someone mentions it's carbon then I want to know what type as I know this will greatly effect the performance, stiffness and strength of the product. It's not good enough to not know what you are buying considering the price. Would appear from your posts you are not interested but suggest you Google Dragon Plate and have a look at carbon fiber tail shafts. Cheers I'm out

mushroom

chrisjon65
chrisjon65's picture
Stocks

Ozeboy
I think your miss interpreting what I am trying to say .
If competitor/potential customer is interested and wants to discuss stock building,materials ,methods research and development then I truely believe the customer is entitled to discuss those details with the maker .
People who choose to develop and build stocks invest Many thousands of dollars and hundreds off hours in R&D Developing a saleable product and making all that public isn’t a smart thing to do.

ozeboy
ozeboy's picture
Composite Stocks

chrisjon65 I've had then benefit of working in the the biggest plastics lab in then southern hemisphere and had all the equipment to try and find the reason why some laminates behave differently to others at a cost of zilch. Because of this I can look at the carbon weave and guage which one would be stiffer, stronger or floppyer . Nearly everything had a code like the seat you are sitting on. I wouldn't buy a cheap 19-130 cushion but prefer a 45-130 industry coded one because of the extra comfort and longer life. A shonky cushion maker would use 19-130, tell no one at point of sale and not be around to fix the customers complaint.. The cushion maker using 45-130 would want everyone to know how great his cushion is hence a code.
The rifle stock type laminates I tested were all made the same size , dog bone shape . These were clamped either end and pulled in opposite directions until destruction and the forces measured. The next test was clamp one end, apply a downward force to the other end and measure the speed and return to zero accuracy when the force is quickly removed. The next test was to clamp one end ,apply a force to the other end , leave for 12 hours, then measure how complete the return to zero is. The laminates were also tested for impact and abrasion resistance.. The epoxy resins were also tested for impact resistance and compression I would have liked to do vibration tests but we didn't have the equipment to do that No testing was done with timber or aluminium inserts. Does that answer your first paragraph.

If you went and Googled Dragon Plate they make a big thing of showing what's in their laminates.

I'm freezing because our aircon has broken Have to go.

mushroom

ozeboy
ozeboy's picture
Code for Composite Stocks

I think you may have over estimated the cost of developing a composite stock as I believe most have or worked in the industry and have the equipment and knowledge to make a good stock. Some want to make something better by adding better and more material while others just want to make money. The latter are usually copiers of successful or best selling products. If you want to make something special then I wouldn't look at the stocks made but try the Aircraft or racing Yacht hull building industry. I believe the aircraft building industry far ahead of most others and I try to duplicate them in most respects. A couple of examples, they use prepreg and vaccuum down to a mould, then cure for 48 hours at 45 degrees Cin an oven. This enables them to have the best carbon to resin ratio and total cure. My method is to make my own type prepreg by wetting out and rolling away the excess resin. My oven is a 20mm thick ply box with an oil heater thermostatically controlled for 45 degrees.
I think a code for best practices to get the best out of the laminates is possibly a bit ambitious but a code for the laminate would be extremely helpful in deciding what to buy. Honesty among manufacturers would be most important to make the code work.

mushroom

chrisjon65
chrisjon65's picture
Experimenting

I like your ideas about composite design and materials.
I have friends in the model aircraft industry who are world champions and I totally understand your reference to other areas of expertise that potentially can be developed into stock making.
There are polymers and plastics used in many different industries that have potential.
I have been involved in competitive combat robot sports and am aware of all sought of
Of structural low weight ideas that scientists are developing.

ozeboy
ozeboy's picture
code for CompositeStocks.

Thanks chrisjon65 nice to see someone has an interest , would be nothing worse than to bore the socks of you all. I'm aiming to show how the construction influences the performance and why a code would help identify it's construction. I am not a composite stock manufacturer but an experimenter who has the good fortune to have had access to a fantastic testing lab. The few tension testing to destruction mentioned before was very enlightening. Woven carbons such as plain weave and twill did not reach full tension before the resin fractured even though a flexible epoxy resin was used. Because the fibers are kinked due to 180 degree cross woven fibers they stretched further than the resin . Straight fibers like the unidirectional were at maximum tension well before final destruction. Hope you had a look at Dragon Plate.pictures showing a straight fiber laminate with a woven twill outer for cosmetic appearance The reason I suggested looking at the carbon tail shafts as this shows the straight fibers being woven in the direction of the tension and compression forces. I'm freezing so will go but will try to explain how I think this applies to a rifle stock and a code of materials therein

mushroom

John B
John B's picture
This is a very interesting

This is a very interesting topic. Please keep it going Bruce.

ozeboy
ozeboy's picture
Carbon Composite Stock codes

Thanks for your interest John B and chrisjon. Pleased you have found one of the reasons why I have been engrossed in this topic since 1970 when I made my first fibreglass stock. and in 1973 when I produced what was known to be the first carbon. I was going to list down a lot of best practices hoping to fix a code to them but think you may get a better idea if we build a stock here. For this role play you are the customer and I am a structural engineer with knowledge of high performance youch hulls and aircraft parts whom you approached to make a stock. I am known to have no shooting knowledge and have never shot a rifle.

So from your description you want the best composite stock possible with no weight limitations, just make it and keep the weight down as far as possible. You have had a pattern maker make the design of your choice and a fibreglass factory do a mould for you. I have requested a visit to a shooting range where I can gage what is required of this stock.
Firstly I want to know the tension and compression areas and when sitting ,recoiling twisting during fire. Would appear the underside of the stock is in tension and the top in compression. The front of the action produces compression and the tear tension and when firing the stock tends to twist as the projectile travels down the barrel. Having observed this its time to design the composites. These can't be seen for they are like the frame of a house where you have to get up in the roof or observe before the gyprock is fixed. Best way to observe what and how much reinforcement is used then burn the resins off leaving the reinforcements for observation.
This stock has to be the best so I choose straight fibers that are not kinked like woven fabrics. These are are laid ready to take up instant compression and tension forces. The fibres are arranged straight along the top and bottom of what will be the finished stock. Then another 36" long by 12" lot of fibers are to be approx 20 degrees off the centre line and duplicated at 20 degrees on the other . The three groups of fibers are now laid up like a fish skeletan with swept back ribs. Now the twisting forces need to be addressed by wrapping a straight fiber around the stock in a circular fashion as I pointed out on the carbon tail shaft site. To make it as light as possible each group of fibers are put through rollers to force the resin through and squeeze off the excess that just adds unnecessary weight. This is the method I use to produce exceptionally light stocks. There's a fine line between resin richness and a semi dry laminate. If the carbon looks like it's in a deep pool of water then it's most likely resin rich. .So the stock is in the mould is ready for cure so intot the hot box for cure at 45 degrees for 48 hours. Just keep in mind that the fibers give strength, stiffness and lightness while the resin just holds the fibers in place. Carbon is used in just about every high performance product in the world having a strength to weight ratio greater than steel. The lab trials of different composites and association with an aircraft parts maker and racing boat hulls has been quite fascinating. I have come to the conclusion a code to cover best practices is not workable Web could do another post on how this effects our shooting but you are possibly sick of it all by now.

mushroom

chrisjon65
chrisjon65's picture
Carbon fibre

In relation to carbon fibre coated stocks ,
Bruce, I am interested in your opinion as to wether the carbon fibre would create true rigidity to the stock or really acting as a hard outer protection cover only
Most carbon coated stocks have the weave running diagonally along the stock.
Someone I know mentioned the matting laid on a horizontal and vertical direction would increase the lateral strength any thoughts?

ozeboy
ozeboy's picture
code for Composite stocks

Nice to see you are still interested. The coating or one layer diagonal outer on wooden stocks is Twill which is mainly used for cosmetic appearance. Seems the stock makers just copy one and other and being able to call a timber stock a carbon stock attracts more attention. Twill is woven to have less cross strands in the weft than the warp. It's stronger in the direction where there is less cross fibers which cause more kinking. Twill is very easy to use as it contours easily and easier to get a good look. I haven't used woven carbon fabrics for at least 15 years but go with the straight fibers even though they are more difficult to use. It's all about having a system flexible enough that enables one to use some of the much stronger straight fibers. Woven fibers look like sheep wool being kinked and can travel a long distance when stretched apart before they end up straight and in maximum tension. I have never gone in for the twill look and just sold stocks straight from the mould.. Please don't order one for I suffer from exposure to epoxies resulting in slight dermatitis and scratch my arms and face for three weeks when making a stock. I have tried a non greasy Barrier Cream taking care to remove it all with a dry cloth before xpoxy contact.

I must share with you some funny instances, one being a friens who I met at a Canberra shoot showing a recent American purchase of a custom rifle. I mentioned how he would not have any excuses now but I noticed the stock tad two large thick chips which suggest it was seriously lacking reinforcements and was resin rich. I didn't mention this as shooting is also a mind game.

My wife will call me shortly for dinner but must mention how weight is bandied around like it is strength. I once had to build a stock for a guy who wanted to replace a hand laid up twill stock who wanted it stronger and to the original weight. I made a straight fibre stock and removed all the excess resin making the customer very happy.

mushroom

ozeboy
ozeboy's picture
code for composite stocks

There are so many great composite products like the USA Americas Cup yacht, Apache helicopters , Stealth planes and the new composite plane that super cedes the 747.. There's a composite to suit and enhance almost every product an example is one of the Sydney to Hobart yaht Ella BAshe. When I heard it's Kevlar reinforced, made me think it will break in half on a large swell because Kevlar stretches a long way and might cause the resin to crack. Further reading made a big thing of the Vinylester resin that I know will stretch a long way.. Straight fiber carbon products have an almost ring sound when dropped on a hard surface, the opposite to Kevlar. The tests carried out in the lab were considered beneficial in a stock. The test where one end of the sample piece of stock was clamped one end, the other loaded, then removed allowing the composite to fly back to zero duplicates very hast group shooting. The speed to zero and accuracy I thought very important.

I have tried to highlight the importance of different composite constructions that can't be seen and make you look further .
A code similar to one mentioned in earlier posts would be a great help and I'm here to work with anyone who is willing to start. This is all about composites and does not knock timber or skeleton aluminium stocks in any way, the choice is yours.

mushroom

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