Ways in which to improve walnut blank/stock properties to improve accuracy.

[ZAR LRH]

Busy building a 300 NM on Barnard PL an 32" Walther 1:9 twist. Will make use of alu v bedding block from Barnard.

Looking at stock options and while searching around for a laminated blank stumbled onto a exceptional piece of walnut that is large enough for the stock I have in mind. The main priority in mind is accuracy, but it wouldn't hurt having a nice walnut stock to finish the rifle of with.

What can be done to either the blank or stock to improve the properties and get it as stable as a laminated blank?

Someone mentioned that the alu v bedding block is al that is required. Will the use of pillars with the bedding block assist and is there a optimum configuration?

Can one impregnate resin into the stock/blank and if so, how and what resin should be used?

 

[Dr. Vette]

I'd see if Accurate Innovations would use your blank to make a stock for you:

http://accurateinnovations.com/

Accurate Innovations Gunstocks

 

[ZAR LRH]

Thanks DR Vette. Had a look at them but the import and export would be a big challange currently.

 

[J E Custom]

Busy building a 300 NM on Barnard PL an 32" Walther 1:9 twist. Will make use of alu v bedding block from Barnard.

Looking at stock options and while searching around for a laminated blank stumbled onto a exceptional piece of walnut that is large enough for the stock I have in mind. The main priority in mind is accuracy, but it wouldn't hurt having a nice walnut stock to finish the rifle of with.

What can be done to either the blank or stock to improve the properties and get it as stable as a laminated blank?

Someone mentioned that the alu v bedding block is al that is required. Will the use of pillars with the bedding block assist and is there a optimum configuration?

Can one impregnate resin into the stock/blank and if so, how and what resin should be used?

A wood stock can never be as stable as a Laminate because the grain all runs in one direction and is susceptible to warping as the humidity changes. The best you can do Is to do a complete Pillar bedding and float the barrel. This will have the best chance of minimizing the warping effect.

I have tried many ways of stiffening wood stocks and none eliminated the change caused by weather or moisture. It helped some but did not eliminate the problem. The laminates are laminated with many different grain directions and the use of resins throughout the stock thickness makes these stocks very stable (And also a little heavier).

I love the fine wood stocks and have a few, but these have been pillar bedded and floated to get there maximum accuracy but over time they are subject to change the POI and need to be sited in before hunting season.

J E CUSTOM

 

[ShtrRdy]

An 'ole friend who is an active benchrest shooter made a stock from a walnut tree he planted many years ago and had to cut down. To help stiffen the stock he laminated a sheet of carbon fiber down the middle of the stock. It sure turned out Purdy.

 

[climb-101]

i have wondered about stabilizing wood for a stock. i know of a few people that do this for pens and duck calls basically turning them into waterproof block before turning. the process is placing the wood in a clear solution in a vac chamber and drawing a vacuum for a few hours on the wood in the solution. once this is done they have to cook the wood at a low temp to set the solution and harden it. i know some of the wood will double in weight once this is done and makes it a very solid block. I made some spalted tamerak grips for a pistol with some of the wood.

 

[Bullet bumper]

" 300 NM on Barnard PL an 32" Walther 1:9 twist. Will make use of alu v bedding block from Barnard. "
And then add a wood stock ??

This does not make sense to me . those are large cartridge long range components so why install into a wood stock that could change POI with weather changes .
Put them into a KRG whiskey 3 chassis .

 

[ZAR LRH]

Thanks JE Customs! Appreciate the info.

ShrtRRy, I'm already experimenting with carbon fibre between walnut planks. Spoke to carbon fibre experts and got +45 -45 350g carbon fibre and what they think is the best structural resin. Did a single layer clean test but its still not stuff enough for my liking. Will be doing 2,3,4 layer to test the stuffiness of these. The only challenge I have is that the blank is already just thick enough and if I cut away to much wood will have make up for the loss in thickness. Running a different piece of hard wood through the centre is a alternative.

Climb-101, also considering of ways to stabilize the wood. On Youtube there is a few videos but looks like they only do it for small pieces of wood although I'm sure that you will be able to up scale the process.

My understanding is that its the moisture in the wood that causes the problem? So if you can keep it stabile or remove it you will win a great lot.

The other alternative is laminate the blank and perhaps incorporate carbon fibre into the process and the run a centre peach of alternative hardwood or something else perhaps through the centre.

Bullet Bumper, I currently have one other long range rifle that has a laminated stock on. I want to keep the feel on both rifles the same. Thus the reason for wood/laminated stock. Why I didn't go with a something like KRG is the cost over here and that is if you can get hold of one.

Cheers

 

[Bullet bumper]

Then go laminated stock and save the fancy walnut for a lighter stalking rifle .
The whole accuracy evolution has been to move away from natural wood and toward other materials that don't move around , absorb or loose water and don't have a grain structure that can warp on you all of a sudden .
That's why it makes no sense to me as it is going backwards in my mind but hey If that is what you really want then go for it . I can dig bucking a trend .

 

[J E Custom]

I will say that when I do a solid wood stock for myself, I have a method that works well but is very time/labor intensive.

I first strip all of the finish off the stock, remove the recoil pad and clean with steel wool . I also let the stock dry for several weeks in the sun to remove any excess moisture.

Old world master Gunsmiths always hand rub finish expensive pieces of wood and the stocks are normally very stable for solid wood.

First, make sure that you have plenty of time before you start applying the first coat because it is the most important. (I use True Oil Because it will cure/harden with time). Set down with an apron or plastic bag over your knees and rubber gloves and have plenty of cloths cut to 6 or 8'' for application
of true oil. once you start applying the true oil don't stop. Keep the surface wet for as long as you can hold out. (This is the time that the True oil is soaking in the wood and the longer you can keep soaking, the deeper the oil will penetrate). Do every surface including the but stock where the recoil pad was and the barrel channel.

Once you stop applying the True Oil, the penetration ends. after it dries, apply consecutive coats using 0000 steel wool to smooth the surface and level the wood for final finish. when done the wood will look beautiful and is very durable. The more coats the better it will look. This is also an easy finish to repair if it gets scratch because the finish is in the wood, not on it.

If you go this way you will not be disappointed but be prepared for a long process of cote and dry. I have taken several months and many hours to do this but have had zero problems with impact shifts on zeros. I always hesitate to recommend this method because it is so labor intensive, but it works the best for fine wood stocks and is beautiful and durable.

J E CUSTOM

 

[Hired Gun]

If you have the bedding block set into the stock as long as the wood doesn't touch any part of the barreled action the wood is just a grip for the bedding block. Stress free bed the action into the bedding block and then be sure the wood is sealed inside and out to protect it from the rain. It will still warp with weather changes but as long as you keep it off the metal point of impact shouldn't wander.

 

[ZAR LRH]

Thanks again JE Custom. Will defiantly be using True Oil to finish and seal the stock with. Putty one can't use the True Oil to vacuum empregnate the stock. Would have been ideal perhaps. Quickly had a look at some videos and some do dilute the True Oil for the first few layers.

Hired gun, someone also told me the same thing. Wouldn't the movement of the wood vary the pressure on the bedding and on the bedding block and influence the harmonics/barrel vibration?

Spoke to a local gunstock maker. His suggested solution is to cut the blank in half and reinforce it by putting a strip of hardwood or laminate down the middle. This looks like the trend everyone is following if they use solid wood for long range rifle. I'm milling with the idea of perhaps trying to get thin hardwood that matches the lighter color of the blank and building up a centre piece with this wood and carbon fibre.

Perhaps a little over engineering but I don't currently have the dimension of the Barnard PL bedding block but was thinking that building a aluminum of titanium box about 2-5mm bigger that the bedding block. Then have this box bedded first and then bed the bedding block into that. External pressure from the wood will be absorbed by the outer box.

Some make mention of a bedding epoxy with elastomeric flexibility properties that also has a very high sheer and tensile strength. Does someone have a name for epoxies with this properties that I can consider using?

 

[Bullet bumper]

Don't like the idea of this separate box to bed the block into . The more complicated the connection of the block to the wood is the more things can go wrong .
Might be easier and more rigid to have a simple bar chassis made and screw the walnut stock to each side like AI side covers. Will look like a walnut stock but have the benefits of a full length chassis inside .

 

[65WSM]

I like to use graphite fibers to reinforce the barrel channels of all of my rifle stocks. Composite, Plywood or single piece walnut. I order graphite from Tap Plastics and use either their 100% resin or Brownell's Accuglass to laminate with. This Richard's walnut stock has 4 layers of graphite fibers in the barrel channel. The forend of the stock has a modulus (stiffness) that is about twice the "heavy varmint contour" of the barrel.