Harmonics and F-Open stock

[Karlandco]

Hello,
I'm building an F-Open rig using one of these stocks glued into a Borden.: McMillan, Cerus and X-Ring. Being a cabinet maker I admire exotic wood, but I'll lean towards accuracy over aesthetics every time. Is there any wood you would recommend for harmonic dampening? Or is there another material more in line with this idea?

 

[Dusty Stevens]

Hello,
I'm building an F-Open rig using one of these stocks glued into a Borden.: McMillan, Cerus and X-Ring. Being a cabinet maker I admire exotic wood, but I'll lean towards accuracy over aesthetics every time. Is there any wood you would recommend for harmonic dampening? Or is there another material more in line with this idea?

Foam filled fiberglass shell.

 

[LVLAaron]

Recovering wood guy..... I like wood stocks.. but for a bunch of reasons, I'd take a good fiberglass stock any day of the week over wood.

 

[X Count]

Really? Why's that's?

 

[LVLAaron]

The main reason is, wood moves. I don’t care what you do to stabilize it.

 

[gunsandgunsmithing]

The main reason is, wood moves. I don’t care what you do to stabilize it.

Fiberglass moves too, but not nearly as bad. It moves a tiny bit with temp but over time, it can move a pretty fair amount as the resin cures for a long time. Still, typically less than wood, though. You can mildly shape fiberglass in the sun. Anyone that thinks fiberglass is stable, is mistaken. It moves too. But I agree with you...with wood, it's an absolute certainty that it WILL and DOES move with temp and humidity. I love wood but not on a serious comp rifle.

 

[LVLAaron]

Fiberglass moves too, but not nearly as bad. It moves a tiny bit with temp but over time, it can move a pretty fair amount as the resin cures for a long time. Still, typically less than wood, though. You can mildly shape fiberglass in the sun. Anyone that thinks fiberglass is stable, is mistaken. It moves too. But I agree with you...with wood, it's an absolute certainty that it WILL and DOES move with temp and humidity. I love wood but not on a serious comp rifle.

Well said. Now, how much does it matter? I don’t know yet. That’s why I’m building an FTR rifle in a wood stock.

@Karlandco Plenty of top shooters out there using wood. So don’t let my opinion color yours if you’re trying to make decisions.

 

[Karlandco]

I'm not a professional on this subject but I would ascertain the bedding mitigates some stock movement. That would then lead me to think since the bedding doesn't give way from it's adhesion to the wood stock, then the bond between the two is stressed as time progresses or environmental change...but still doing its job. How the harmonic values transfer across these barriers and what wood may/may not absorb or reverberate familiar nodes...is what my question relates to. I'm sure we could have a more productive conversations about wind calling or barrel tuning but I'm building a rifle and thought I would ask if my thoughts are legitimate or if I'm throwing pebbles off a cliff. Thanks for your time.

 

[davidjoe]

I know a lot us like audio equipment, usually it’s the guys that double up on the hearing protection with plugs inserted so deep they need a key to remove, because these two interests are at odds with each other.

Nothing wants to set itself into harmonic resonance more than a loud speaker. The goal of a good enclosure is to avoid coloring the sound of the transducers with its own tendency to start ringing.

On purely that captioned question of harmonic dampening, braced or thick wood or wood products such as MDF, is just about universally accepted as the best material to dampen vibrations across the entire spectrum of frequencies.

That’s not the only priority for a stock, as I reflect on the worst downpours ever in Ottawa in 2017, but I think among the other stock options of composites and metals, thick wood dampens vibrations better and is inherently nonuniform across its length so as to resist harmonic resonance as well.

 

[Karlandco]

Well said. Now, how much does it matter? I don’t know yet. That’s why I’m building an FTR rifle in a wood stock.

@Karlandco Plenty of top shooters out there using wood. So don’t let my opinion color yours if you’re trying to make decisions.

I appreciate your opinion either way. I hope my findings on the subject lead me to go wood. It's just so damn classic as it's been around since the dawn of the sport. Just yesterday I found a picture of a wood stock built probably 10 or so years ago. Your aware, the technology that's leaped and bounded in the past 10 yrs you would've thought it was outdated in appeal and sporting obsolete technology. It was anything but. Enough color for character but quiet enough that it was always going to be a man's gun. Long sleek lines that commanded appreciation, only thing that really meets the eye is well made function. All in the eye of the beholder but you can't get that from a lot of other materials. Good luck with the new build, send me a pic if it crosses your mind.

 

[Karlandco]

I know a lot us like audio equipment, usually it’s the guys that double up on the hearing protection with plugs inserted so deep they need a key to remove, because these two interests are at odds with each other.

Nothing wants to set itself into harmonic resonance more than a loud speaker. The goal of a good enclosure is to avoid coloring the sound of the transducers with its own tendency to start ringing.

On purely that captioned question of harmonic dampening, braced or thick wood or wood products such as MDF, is just about universally accepted as the best material to dampen vibrations across the entire spectrum of frequencies.

That’s not the only priority for a stock, as I reflect on the worst downpours ever in Ottawa in 2017, but I think among the other stock options of composites and metals, thick wood dampens vibrations better and is inherently nonuniform across its length so as to resist harmonic resonance as well.

Interesting analogy. Plus 3 for wood. Any wood? or is harder/softer make a difference...I should've been a musician.

 

[Alex Wheeler]

They both move but in different ways. You can look at wood like a sponge, it will absorb moisture or dry out. The more figured the wood the worse it mores in my experiance. Laminated wood is actually pretty stable. Theres just a lot of epoxy in it. Theres different designs out the using carbon to stop the stocks from warping or twisting. Roy Hunters stocks have a carbon fiber triangle down the middle the entire length. Fiberglass wont move as much with humidity changes but in my experiance it moves more with temp changes. This is why I am a fan of glue ins. All stock materials move in some way or another and if the action is bonded to the stock there wont be a change in contact between the bedding and the action. Which shoots best? I would not have a problem building myself a rifle on either. My last rifle was laminate, the one before glass. I did like the foam Like Dusty said, but McMillan wont do it anymore.

 

[Karlandco]

They both move but in different ways. You can look at wood like a sponge, it will absorb moisture or dry out. The more figured the wood the worse it mores in my experiance. Laminated wood is actually pretty stable. Theres just a lot of epoxy in it. Theres different designs out the using carbon to stop the stocks from warping or twisting. Roy Hunters stocks have a carbon fiber triangle down the middle the entire length. Fiberglass wont move as much with humidity changes but in my experiance it moves more with temp changes. This is why I am a fan of glue ins. All stock materials move in some way or another and if the action is bonded to the stock there wont be a change in contact between the bedding and the action. Which shoots best? I would not have a problem building myself a rifle on either. My last rifle was laminate, the one before glass. I did like the foam Like Dusty said, but McMillan wont do it anymore.

Anything wrong with epoxy in it? Heavy but will it push 22 lbs further than wood? Carbon sounds $pecial, Never heard of Roy Hunter. I'll look him up.

 

[Alex Wheeler]

Roy doesnt build stocks anymore. Nothing wrong with epoxy fill.

 

[davidjoe]

Interesting analogy. Plus 3 for wood. Any wood? or is harder/softer make a difference...I should've been a musician.

All my thoughts are based on other’s wood F-Class stocks, but I once had a convo with the forum boss about how it’s important with these long fore end wood stocks, to keep the bottom thick enough that it remains structurally rigid.

I think you’d want to sketch out an X-ray view. It’s that area around the lug, that sinks deep, and the thinness of most stocks before the barrel shank, where material is getting spartan. And the wrist, elegance is not a friend, right there.

I truly love walnut, for its potential figuring and strength. Some hardwoods are a little more brittle than others. If the hardwood is of a tree that produces an oily nut, I tend to think of their heartwood as very durable and bit less brittle. If the hardwood tree produced bean pods, common in the drier climates, that can be extremely hard, but more brittle. One of my favorite Texas hardwoods in appearance and feel is old growth pecan.

 

[muleystalker]

Fiberglass moves too, but not nearly as bad. It moves a tiny bit with temp but over time, it can move a pretty fair amount as the resin cures for a long time. Still, typically less than wood, though. You can mildly shape fiberglass in the sun. Anyone that thinks fiberglass is stable, is mistaken. It moves too. But I agree with you...with wood, it's an absolute certainty that it WILL and DOES move with temp and humidity. I love wood but not on a serious comp rifle.

Not only does fiberglass move but it can warp and take a set in it. I have seen fiberglass boats that weren't put on the trail centered on the bunks evenly and then stored that way for a couple years. It would never track right after that, it was downright dangerous at mid speed and some small swells, it would hook had to the left coming into a small swell or big chop.

 

[X Count]

I like laminated timber but they are all different and the stock material is just one part of the system. Stock should be sealed with multiple coats of 2 pack and bedding should be checked often.

The balance of the gun, flex / rigidity of the stock, front rest, rear bag design and type of fill all effect the harmonics and how the gun handles. The are all unique and some combinations shoot "dead" and others don't.

 

[Karlandco]

I like laminated timber but they are all different and the stock material is just one part of the system. Stock should be sealed with multiple coats of 2 pack and bedding should be checked often.

The balance of the gun, flex / rigidity of the stock, front rest, rear bag design and type of fill all effect the harmonics and how the gun handles. The are all unique and some combinations shoot "dead" and others don't.

What does this mean "shoot dead" and how does one know this?

 

[Alex Wheeler]

You will hear that phrase a lot. Some rifles shoot smooth. They don't ring or vibrate. The crosshair comes back straight without bouncing around. Even stocks of the same make can be different. I remember a glass stock I had a while ago that rang like a bell. It shot well but it bothered me. After I fixed it, it shot the same. But it didn't ring. I know other guys have had stocks that ring. Take the scope off and see if they still ring....

 

[gunsandgunsmithing]

I've toyed with a couple of aluminum stocks and I'm big into vibration management, fwiw. Neither aluminum stock shot particularly well until I did some things to the last one to dampen it. The gun definitely improved a bit but not night and day, as it wasn't bad to begin with. I just always felt like it was leaving a little bit on the table. Weight was never an issue with it, so I could do whatever I wanted without that concern. One thing I did was I milled a slot in the bbl channel that extended a bit under the receiver. I made an attenuator from aluminum tubing that I filled about 80% full with tungsten powder, same as my tuners, btw. It was only attached at one end, under the receiver and floated the rest of the way, about 8". Before this, I could rap it on the but and it would ring in my hand. Afterward, that ring was all but gone. It made a noticeable difference in how the gun shot, for the better but again, not a day and night difference. I shared the idea with a couple of others who did the same thing. They both felt like it helped their respective rifles too, fwiw.

I've also done similarly on fiberglass stocks using a milled slot in the bbl channel and filled it with two part silicone. I can't say if it helped or hurt as i had no baseline for how it shot before but the gun is a very good shooting rifle. I enjoy classes that allow experimenting with these types of things. A 10.5lb rifle doesn't leave a lot of room to do stuff like this. The aluminum stock was really heavy but I don't remember the exact weight..thinking 22lbs. The fiberglass was intended to shoot Unlimited so we had weight elsewhere in it as well but the silicone didn't add much weight..maybe a couple of ounces. Oh...just remembered...I also used it in the butt around the weight system in the stock. That gun feels and shoots very "dead", fwiw. Bottom line, it's a great shooting rifle and I didn't see any down side to the dampening but I can't quantify if it actually helped or not.