Home Forums Hunting & Shooting Ask The Gunwriters Laminated wood for extremely heavily recoiling rifles?

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I am aware of several laminated wood stock blanks available: Rutland's ubiquitous birch; obeche; walnut-maple; walnut; and Kilimanjaro's walnut laminate. Most are 15-18 plies per inch, but some have thicker plies.

Excluding Kilimanjaro's laminate that I cannot afford, are there significant mechanical differences among the various wood laminates? I specifically do not refer to colors, quality of finish the wood accepts, difficulty shaping, or other cosmetic differences; cosmetics can be rendered whatever way I am willing to pay for. I am interested in the wood's ability to take a beating over the long haul.

There is a difference. We sometimes hear of delamination of the birch laminates but in every case I have see, the stock did not actually de-laminate but the veneer split. So, it would seem the limiting factor is the inegrity and stremgth of the veneer. I never did see any of the problems with splitting when we were using the maple/walnut laminates as sold by Fajen.
With any of the birch laminates, one will want to do some re-inforcing to prevent splitting from a heavy recoiling rifle. GD

I used Rutland plywood for building bow risers. Never heard of a failure. Did have some problems with a few offerings from a company called Pakawood. It was not their fault. They had some that had very high resin content and were strong but brittle. They warned us ahead of time but we were building personal bows that wouldn't be sold. They came out absolutely stunning and I used mine for several years before I accidentally dropped the riser on concrete and it shattered.

I have seen birch laminates by Rutland splinter even when reinforced with heavy-recoiling rifles. Of course a lot depends on the reinforcement, but I haven't found birch laminates much more resistant to recoil than standard walnut.

The Kilimanjaro laminate only has three layers, but is usually a stronger than birch laminates because of the walnut used is stronger. On hard-recoiling rifles they still reinforce it with cross-bolts.

There is a big difference between the strength of a bow riser and a gunstock, mostly because the stresses are in very different directions. In a bow riser they are at right angles (or close to it) to the wood grain, and in a rifle stock they are linear.

Pretty close, but not exactly...

Stock bolts and such in lab tests have proven to be pretty unreliable as real strength... and uless done exactly right they are a deficit, not an advantage.

The biggest stock stressor in recoil is the flare at the magazine. That equates to lateral movement. The little relief cut aft of the tang is there for a reason.

Yellow birch is usually the wood in the best laminates and it is virtually equal to or better than walnut in every strength category but one... It even bests walnut significantly in bending strength and resilience... But it is not nearly as good in tension perpendicular to the grain. Perhaps 70-80% of walnut which is why it is known to come apart under severe recoil sometimes.

Obeche is a whole other animal... The stuff is very light, like twice the density of balsa, but half of walnut, and weak. Building a sandwich with it as the seperator between multiple chords produces a fairly strong, very light stock for low-recoil bench rest rifles. It is not shock tolerant, so care has to be taken in design and assembly. A light stock allows for more metal in the barrel where the weight will do some good.

I hate laminates!
art

How is maple in that regard?

Not fond of laminates personally, but some people have turned out to quite pleased, particularly with the price.

Maple is FAR too varied as wood goes to begin to answer that simply. On the soft maple end you have some near-punk up to relatively light, but strong for its weight bigleaf. And on the hard maple end you have red and sugar and rock groups... All of which are quite strong and the rock and sugar are super strong, but heavy.

Walnut is still stronger for its weight than any maple, but the hard maples have a slight advantage on average over walnut on splitting (tension perpendicular to the grain), but it is also more dense. More wood in the wood is a good thing when looking at strength characteristics usually.

Thanks, I had hard maple in mind but I suppose it's a bit of a crap shoot in a laminate.

The thing with the birch in the Rutland materials is not because of it's type but because some of the veneers used are of poor quality and have even less resistance to splitting than the average.
A cross bolt behind the magazine well can help but a dowel glued through the same area is probably better. The same is true behind the recoil lug. A cross bolt is good but a dowel embedded across the grain might be better. In either case, the re-inforcing piece, whether dowel or crossbolt, should located well behind the recoil lug mortise. GD

What is the best reinforcement for the recoil lug? I always wondered how much strength there is in gooping in epoxy with a small percentage of fiber. Are the steel beds significantly better? I always thought a steel plate inletted in behind the recoil lug and just skim bedded with one of the better epoxies was best, is it? And if this is done would a dowel or cross pin help in any way?

greydog
Take a close look at the Rutland plywood with a hand lens and you will be able to see exactly why you are correct about the quality of the plies. Their veneers are rotary cut which means the outside of the ply is longer than the inside of the ply. You can see the distortion in the grain. That does not make it stronger.

The biggest problem with reinforcing behnd the mag well is the lack of meat to reinforce there... and doing it with a metal pin, especially the brass used by Remington for example is the fact glue will not last beyond a few temperature cycles. Those pins are just to keep the pieces in place when they crack out.

Glass bedding with a little fiberglass in it proved better than any other system, including skim bedded, properly positioned recoil lug cross bolts.
art

I think I responded to most of what you asked already, except the notion of a steel plate. The whole idea is getting the recoil transferred to the stock at the recoil lug(s). With good wood like European walnuts a skim bedding just to ensure perfect mating is plenty. Softer and weaker woods can use more surface area between the epoxy and the wood. The integrity of that bond is the weak link.

My BR rifles have laminated wood stocks. My light rifle[10.5lbs] is redwood laminated with carbon fiber cloth. We hand picked the redwood to get the lightest planks. My heavy rifle[13.5 lbs] is black walnut with carbon fiber cloth. Carbon fiber runs vertically and horizontally. We did not clamp the wood with clamps. We vacuum bagged them. We used redwood on the light rifle as it is lightweight and very stiff.






You can probably see I mixed photos of the redwood and walnut stocks. We did from the rear of the receiver forward in one setup on the mill. Wanted the barreled action to be straight with the wood. I enjoyed doing these, but never again. They are very stiff and strong.
Butch

Art,

Interesting information on cross-bolts. In your experience what is the proper way to install them?

+1.........

hey art,
how come you have so much time to give advice and info about this subject and i've yet to hear from you about my stock you've had for a year now ?

riddle me that !

you ever gonna contact me and let me know when you plan on finishing it and returning it to me, seein as i paid you up front for the work ?

thanks art, i know you will understand my position here and contact me real quick and give me some kind of update or info about it.

Semantics will get in the way of a straight answer... Originally the crossbolts were bored through fairly well aft of the recoil lug, no metal to metal at all. Most Guild members probably consider that the proper way to do it. It adds virtually nothing to most stocks in terms of strength or split resistance.

Installing them perfectly with full contact on the recoil lug, no bedding, is stronger than the blind hole in walnut, but not by much.

Skim bedding close to the lug is better but not close to fiberglass reinforced epoxy bedding spreading out well beyond the action. I crushed a lot of wood to prove it to myself...
art

Hey Art,

You obviously are very intelligent and have a lot of experience with wood stocks but why don't you return Splatt's stock that you agreed to work on in exchange for the barrel blank that you received??

Your character can be questioned by your actions with others.

splatter,

You paid him up front, he's had it over a year, and he won't communicate with you? Tells me one thing, the guy's got no integrity and zero class. But he does have his little band of sycophants that thinks he walks on water.

guess i gotta call him out again.
no contact at all.
he won't open a pm i sent about 2 months ago, nor return a phone call. i left a message on his home phone, nor come out in public and say anything.

hey art peck,
at this point, i don't care if you have finished my stock.
you've had it long enough to do the work you agreed to do, and i'm tired of waiting for it.

send everything back the way it sits.

do i need to contact law enforcement in anchorage, like some have suggested ?

do you even still have it and didn't sell it, or put it on one of your own personal rifles ?

at this point you are denying me, my property.

are you a thief ?

send all my stuff back to me.
the stock, the complete cartridge trap, and the .25 caliber barrel blank, that was used for payment.

enough is enough.

you have plenty of time to chime in here on threads, but cannot open a pm i sent you, or work on my stock ?

there is a problem here, and i think you are all talk about stocks, and havn't the skill to do a simple cartridge trap inlet.
you bit off more than you can chew ?
did you mess my stock up ?

come on art, answer some questions.