Pounder Kevlar stock?

[TaperPin]

What ever happened to kevlar for light stocks? I bought a pounder stock from Brown Precision 25 years ago and the blank was literally 16 oz. Strength to weight CF beats Kevlar a little, but I liked the idea of Kevlar not breaking quickly if it’s going to fail. Everyone seems to make CF stocks, but most are so heavy they might as well be fiberglass, and the light carbon fiber ones are still above a pound. Is CF the way to go?

In my 20s I vacuum molded a stock over a plug, but the plan had a number of fatal flaws and I chocked it up to an expensive learning experience and never tried again. Vacuum bagging or a pressurized inner plug seems to be essential to reduce the epoxy weight to a minimum.

Recently I ran across what I think is left over cf from an airplane build for almost free and it reignited an interest in a super light diy build.

Any others with a diy stock project?

 

[Gobber]

TP-
If you have the supplies, I recommend going for it! I’ve done a few prototypes for a toggle bolt .22 that worked well for me. Not the prettiest gal at the dance, but fits my wants and has held up well. It was made using a Coosa Board section at the inlet area, hockey stick shaft for the buttstock area and a section of hex tube I purchase. Grip is a bit of foam molded to my hand with an outer 4 layers of 6k. Whole stock is one kilo.


What weight CF do you have?
What style stock are you thinking?

Reducing weight on a build is one thing, going super light weight can get complex- especially if it‘s for a hunting caliber rifle. Have to do internal reinforcement of the inlet area to transfer the recoil energy to the outer CF structure. Very doable, but takes a bit of forward planning. CF is neat stuff, but doesn’t hold up well to repeated high energy flexing over time.

My current project is a CF “spined” walnut build where I hope to be able to cut away a lot of the wood for light weight while still maintaining a good look and the adjustability that I like.



It’s a first try with several flaws, but pretty comes later, maybe.

 

[TaperPin]

TP-
If you have the supplies, I recommend going for it! I’ve done a few prototypes for a toggle bolt .22 that worked well for me. Not the prettiest gal at the dance, but fits my wants and has held up well. It was made using a Coosa Board section at the inlet area, hockey stick shaft for the buttstock area and a section of hex tube I purchase. Grip is a bit of foam molded to my hand with an outer 4 layers of 6k. Whole stock is one kilo.


What weight CF do you have?
What style stock are you thinking?

Reducing weight on a build is one thing, going super light weight can get complex- especially if it‘s for a hunting caliber rifle. Have to do internal reinforcement of the inlet area to transfer the recoil energy to the outer CF structure. Very doable, but takes a bit of forward planning. CF is neat stuff, but doesn’t hold up well to repeated high energy flexing over time.

My current project is a CF “spined” walnut build where I hope to be able to cut away a lot of the wood for light weight while still maintaining a good look and the adjustability that I like.



It’s a first try with several flaws, but pretty comes later, maybe.

Those stocks are great projects. I hadn’t ever thought of a wood stock with carbon spine, but there are some really nice stocks out there that seem to sell for really high $$$$. Very nice - looking forward to seeing the end result.

In a lot of ways they are more complicated than what I’m thinking of. Tentatively, I‘m aiming for a rather traditional shape with raised cheek piece - like a Remington BDL, but with a slightly higher cheek piece to better fit higher optics that are so common nowadays.

I’m bidding on used eBay stocks to modify and smooth out in order to make a mold. In the past I’ve tried making a few molds over a factory stock and they didn’t turn out well, but the mistakes seem pretty obvious now and I’m optimistic about it now. The only reason for the mold is the ability to potentially make multiples if sons and nephews want one - they will probably only be excited if it’s a chassis, which is a much more complicated design and mold so a traditional stock is a better starting place. Maybe the mold will only be used for a foam core - nothing is written in stone yet.

I have quite a bit of 3 ounce carbon fiber fabric, a few pounds of this half carbon half Kevlar, and 13 pounds of a high strength unidirectional carbon tow. The carbon tow is supposedly ideal for adding bending resistance - for instance barrel channel deflection, much like using arrow shafts to stiffen it up. It’s really thin so it requires a large number of strands - unidirectional fabric would be easier to use, but this stuff is so cheap it’s essentially free and it’s the higher strength 70k psi carbon (and there are 65lbs more if I want it). I’ve also seen where unidirectional is ideal for molded “forged carbon” applications - equaling the physical deflection and ultimate failure strength of aluminum - maybe ideal for a chassis? IDK

The large number of carbon fiber videos on YouTube have been great - has really helped nail down good technique, it’s mainly a matter of determining how much extra is needed to reinforce the grip, action and forend areas.

I’ve been picking up details on super light stocks from multiple sources - of course nobody wants to give out all the little details on how theirs is built. It seems super light stocks are most often molded not only on the outside, but also around the action and the full barrel channel. A one pound stock is 40% epoxy and that amounts to only 12 ounces of carbon fiber/Kevlar, actually more like 11 ounces subtracting the foam weight - not a lot there.

Standard weight stocks seem to have a thicker skin and the barrel channel and receiver area are open blank spaces filled in and milled out as a separate step to match whatever action and barrel are being used.

I have some heavy fiberglass gear covers to make for an old metal lathe - that seems like a good way to warm up to making the mold halves, which will also be primarily heavy layers of fiberglass.

 

[Gobber]

TP - You are definitely jumping right into the deep end by going with a mold based fabrication! My hat's off to you. I've looked into the process and even picked up some of the materials (mold resin) but never had a project that required it. Good idea going with some simple geometry machinery covers to start with. Really helps to have a useful target to shoot for in learning a process.

If you haven't already visited, I highly recommend Smooth-On for mold making supplies. Their stuff is top notch and they sell most items in smaller quantities- Amazon has some as well. Been using them for years and everything has performed great - long shelf life as well. Their 2 part foam is outstanding for CF layups as it holds it's dimensions well under vacuum bagging and is very pleasant to sand/shape.

Have you done any vacuum bagging yet? It's a bit of an art to get right sometime, but it does a great job of pulling out the excess resin for a good fabric to resin ratio. I'm a low tech, git-er-done type garage tinker. Old dusty the vacuum rig still works like a charm after several years.


Great idea picking up second hand stocks from fleabay to use as starting points.

 

[TaperPin]

I like your vacuum pump setup. I didn’t need one like yours, but someone was tossing a refrigerator so I grabbed it. It works great.

An inexpensive single stage vacuum pump from cps is what I’ve used - honestly can’t remember if it was new or used or even how long I’ve had it, or where it was purchased, which probably means it was purchased from a pawn shop years ago.

I was a cabinet maker and remodeling contractor for a few decades - I’ve glued up panels and used vacuum bagging as a press, so epoxy bagging with peel ply and breather wasn’t a huge jump.

Years ago I bought a rifle with what resembled an Anschutz silhouette stock - it turned out to be nothing but solid bondo! Not knowing any better, I figured If I vacuum bagged the outside with fiberglass it would be easy to split it with a cutoff wheel in a Dremel, then add a strip of cloth to reattach the two halves. The vacuum bagging went well, but joining the two halves soon became a deal breaker.

Not long after that, I had purchased a Pounder Kevlar stock and thought maybe I’d vacuum bag the factory Remington stock with Kevlar, but instead of splitting it, I bagged one side, removed it, and bagged the second side. Well, it didn’t go much better than the bondo stock when it came time to join the two halves - that technique was not a great idea. I was impressed with how light weight the Kevlar skin was, but never put any more time into it.

It was obvious I’d either have to shape a foam plug, or make a mold. Although I’ve been a professional woodworker, a lack of depth perception has made carving 3d objects with uniform lines and curves a real challenge, or I’d just carve foam stocks for plugs.

Have you tried a resin infusion where the carbon is placed dry, the bag is vacuumed down and epoxy is sucked through from end to end? It requires a thinner resin to properly wet out, but looks interesting - it would be very nice to get a fully sealed bag before mixing the epoxy.

Have you used anything other than the bag sealing “tape”? Inexpensive painters caulking works well to seal a bag for wood glue ups and costs next to nothing, but I don’t know if moisture being sucked out of the caulking would cause epoxy issues.

 

[Gobber]

Good to have experience with all the layers involved in vacuum bagging and see the compression force you can generate with a simple vacuum pump. I've partially imploded a few projects by not placing internal supports and using too much vacuum.

Vacuum Infusion - Ughh, been watching those EasyComposite videos I'm guessing. They make it look sooo easy- bunch of limey Brits. Actually I did a test panel of 10"x10" 12K with 4 layers just for 'fun' but used what I had on hand - West System resin with extra slow hardener. It made it just past half way, started gel, stopped infusing and the most entertaining part was the resin reservoir went exothermic and melted the plastic container it was in. I salvaged the panel by opening the bag and wetting the rest out manually. Resealed the bag, pulled the vacuum back down and the panel turned out fine. Lesson learned - use the right stuff!
Honestly, never did a project that was worth the trouble of setting up an infusion. Maybe some day...

Bagging Tape - Thought about using a substitute early on, but figured that with all the labor, materials and hassle of a vacuum bag setup, it just wasn't worth the few bucks savings on the sealing tape. Plus, I like to re-use my vacuum bags and that bagging tape lasts forever. Sometimes I'll wet a cloth with silicon spray and wipe down the inside of a bag just to get a few more pulls out of it. Now that's being cheap!

 

[Gobber]

I have some heavy fiberglass gear covers to make for an old metal lathe - that seems like a good way to warm up to making the mold halves, which will also be primarily heavy layers of fiberglass.

Now that is a project that would lend itself to a vacuum infusion setup. Long, flat items like plates, covers and such seem to work well so long as infusion specific resin that is really thin, slow to cure and resist exothermic in the feed cup. I’ve iced my resin cup before on hot days when doing a larger layup and it helped a lot to increase the work time. Always good to do the first one or two attempts using fiberglass as it is cheap and easier to form.

For making machinery covers, are there any existing items (container lids, etc.) that you could use as a tool surface to lay your composite over? For my first adjustable cheek rest, I used a piece of 1/4 round floor molding as a form, and it worked really well.



I also made a very thin CF hollow cylinder (4” tall, 14” diameter) using a few layers of green Lowes rigid foam insulation that came out pretty well.



ProTip- the pink foam board from HomeDepot is too soft and collapses under any significant vacuum, BTDT.

That involved a bit of hot wire foam cutting that was really cool to do. Made a hot wire bow out of some scraps in the garage that worked really well for several projects.


Fun stuff!

 

[TaperPin]

Its good to know the pink foam is a bit soft.

Your cheek rest turned out great. The hot wire is something that I’ve never tried, but ran into a roll of wire at a garage sale for $.50 and snatched it up.

The lathe covers essentially follow some gears and other cylindrical rotating parts, with a clearance of 1/2” in some areas, and spanning gaps of a few inches where the shape essentially flattens out.

Being set up with routers and circle cutting jigs makes cutting curved parts out of mdf quick and easy. If I can get a skeleton of the shape, the plan is to use the technique of stretching polyester fleece over the shape and saturating it with polyester resin to get a hard 3d surface as is popular when making free form speaker enclosures for hot rods. (Not my photos)

Then using that as a plug to lay up fiberglass fabric on both sides of the fleece with polyester resin. It doesn’t have to be super strong, but it would be nice if it finished about 1/4” thick with a shape that mimics cast iron.

Then there are a few more complicated small part that might be made with a solid mdf plug and vacuum bagged with epoxy.

The old lathe these covers are for was picked up for scrap price and little by little it’s almost usable. With all the parts and time invested, the main thing a guy with an old lathe does is make parts for the same old lathe. It’s large enough to turn, thread and chamber a barrel, but that’s a stretch goal. Takeoff barrels are dirt cheap, so the tentative plan is to take three .243 barrels, true a rem 700, adjust headspace and shoot them, cut off the threads, recut the threads, rechamber, and shoot all three again. I’d be thrilled if the barrels simply turn out usable with good fit and finish and chamber actually centered in the bore.

That’s a year away - every time it gets exciting and seems close, a different issue is discovered. You know how weekend garage projects go - everything takes twice the effort and three times the time.

 

[Gobber]

Hey, that is a very nice method for making a form. Never seen that one before, but can think of a few very nice applications. Much easier than cutting multiple foam layers and then smoothing it down to shape.

Your lathe project sounds like a good one, though trying. Sure will be satisfying to get it up and running. I absolutely love to rebuild, repurpose, or modify items to suit a specific need.

As with so many of these projects, you can do it Cheap, Fast or Right - pick 2.

The hot wire foam cutting is a very handy, yet simple way to create plugs for vacuum bagging. I did a project a while back for a buddy who was hired to add a vertical lift capability to an existing commercial UAV. My part was to create the main load bearing body shape that mated to the fuselage. Not easy to see scale, but the wingspan is 12 feet.



My part came out pretty well considering that during flight testing, the thing ended up 25 feet up in a tree three seperate times times due to a hidden flaw in the avionics programming. At least the section that I made did not break, but lets say there were other repairs needed each time.



To get the wing shape, I made matching sets of sheet metal templates that the hot wire rode across when cutting the green foam. Once the voltage was tuned into the gauge of the nichrome wire, the cuts were very smooth and the wing forms came out quite nice. For this specific project, the client began arguing over intellectual property rights, both sides lawyered up, and the project died. Worked out well for me as we had just received a delivery of CF supplies that nobody could use except me, so I simply took it as final payment. Win Win for me.

Back to the original subject, I wonder what kind of strength to weight ratio could be achieved using a central flat spine of CF with rigid foam applied to each side to form a plug. Shape the outside contours into the desired rifle stock shape. Then skin it with as much CF as needed. You could always disolve out the internal foam with acetone if you like. This way the central 'spine' could take the recoil force and distribute it to the outer shell where needed by laminating them at various points. Just a thought.

 

[TaperPin]

That drone project is really something! When someone says drone, a 12’ wingspan is not what comes to mind.

Have you watched the carbon fiber build of the Draco airplane on Mike Patey’s YouTube channel? I really enjoyed seeing the build and destructive tests along the way. He crashed the plane here in Reno and never rebuilt it - my uneducated gut feeling is he found a big structural miscalculation that allowed so much damage with what appeared on the surface to be not a catastrophic crash.

The central cf spine is an interesting idea. I see more and more of that in custom and semi custom wood stocks. Many of them have the carbon fiber spline split with a gap about the thickness of the cutout for the trigger - I’ve assumed it’s so the cf is more uninterupted?

The super light Pounder stock seamed to transmit recoil through the laminations on the inside of the action recess back to the top of the hand guard then around both sides of the buttstock. At that time the stock was available as a blank and the overlaps of the layers could be seen peaking through an opaque sage green gel coat. To this day I’m not entirely sure what the mechanism was to press the layers against the mold since the entire action recess was molded and not cut out after the fact, leaving little to no room for a skinny vacuum bag.

It could be a slightly oversized foam plug was covered in resin and Kevlar then compressed a bit in an aluminum mold as I think they did in the Tikka stock making factory video.

A few years ago a client had me remodel the inside and outside of a train caboose he wanted as a yard bar next to a big deck and entertaining area. The painter who finished the interior was really good at a lot of things, but he was having a hard time making the wood bar look like cast iron. On a whim a little black color mixed with polyester resin and rolled out until it was almost dry worked really well. The domed brass furniture tacks are the perfect shape to duplicate rivets and the wooden doors are mdf copied from a wood stove. I built the bar and all the woodwork other than original ceiling. Fun project.

 

[BBob]

My current project is a CF “spined” walnut build where I hope to be able to cut away a lot of the wood for light weight while still maintaining a good look and the adjustability that I like.

Before he offered packs Glen Eberle made a great looking pretty light carbon reinforced wood stock. He didn't sell them for long since they weren't profitable at all. A really long time ago I tried twisting his arm at a vendor show to offer them up again but he was full into the packs. He was an Olympic Biathlon competitor in his early life and that's where building lightweight stocks started for him.

 

[BBob]

What ever happened to kevlar for light stocks?

I have a Brown kevlar from before they were called a Pounder. I bought it as an 80% and finished it. After that one I swore never again. Kevlar is a beotch to finish and time consuming messing with those fibers. As I understand it adhesives such as epoxy doesn't stick to the actual kevlar fibers real well at all. It stays together yes but it ends up more flexible than say a carbon stock. Good? Bad? I don't know. I still have that stock though

 

[TaperPin]

Before he offered packs Glen Eberle made a great looking pretty light carbon reinforced wood stock. He didn't sell them for long since they weren't profitable at all. A really long time ago I tried twisting his arm at a vendor show to offer them up again but he was full into the packs. He was an Olympic Biathlon competitor in his early life and that's where building lightweight stocks started for him.

View attachment 588959

That’s an interesting design - I like it.

 

[TaperPin]

I have a Brown kevlar from before they were called a Pounder. I bought it as an 80% and finished it. After that one I swore never again. Kevlar is a beotch to finish and time consuming messing with those fibers. As I understand it adhesives such as epoxy doesn't stick to the actual kevlar fibers real well at all. It stays together yes but it ends up more flexible than say a carbon stock. Good? Bad? I don't know. I still have that stock though

The Kevlar that I messed around with could be pulled out of a puddle of hard epoxy, so I think you are right about it not sticking.

If Kevlar was more flexible than a normal carbon fiber or fiberglass stock it wasn’t noticeable, but wouldn’t surprise me. It was surprising that BP said in one of the later catalogs that the stock isn’t for anything larger than .300 mag (if I remembered that correctly). While on Kodiak I had an open sighted .375 H&H that only weighed something like 7 lbs and shot hundreds of rounds without issue. At that time Remington used the standard magnum contour barrel and with the big hole in the middle it was quite a light gun.

 

[Gobber]

TaperPin - That is a really neat caboose project. Using polyester resin as a top coat is a really good idea. Give it a really tough coating and resin dye is some of the blackest stuff I've ever encountered. I picked up a little 6oz tub of it several years ago, use it all the time and have yet to consume even half of it.

The idea of using internally applied layers of CF that 'split' around the walls of the inlet area would be how I would construct a light weight, strong, foam core stock. That with a reinforced cross section that maybe housed an embedded metal recoil lug and mounting pillars would be be a great way for the internal structure to hold up to high caliber recoil energy. It would take a few iterations to determine the least weight of material needed to stand up to repeated shots.

The challenge would be coming up with a sequence of layup steps for doing a one off stock. Conceptually perhaps create a good, rigid foam plug using Smooth-On's Foam-It 5. Love the stuff - solid enough to hold up to full vacuum, shapes easily and is still very light. Then precisely cut it where the CF internal layers would go. Wet out the CF, place it in between the cuts and vacuum it down to cure in place. With strategic layering where the internal layers were exposed to the outside surface in the right places, you could get very good linkage to the outside skin layers of CF. Not sure if all that makes sense, but it gets some rusty mental gears turning.

BBob - Glen Eberle's first biathlon stock was my primary inspiration to try making my own stock. I still love the lines of his biathlon stock with the high butt frame contoured for both standing and prone positions along with the molded-in comb. My understanding is that his use of spruce & CF composite really revolutionized competitive biathlon stocks and kicked off the evolution to the space-gun look of biathlon rifles today.

 

[TaperPin]

Gobber - The order of operations laying up over a foam plug you described makes a lot of sense.

I’ve been looking at diy fiberglass molds for various items and feeling the angst of the builders all along the process, mainly in surface finish. For only building a handful of stocks, going away from a mold is probably a lot more bang for the buck, not to mention once you make it one way the next one will probably be different.

What toggle action is that on your .22? Is that from a biathlon rifle? Very interesting.

I‘ve seen an out of context reference to someone who made, or attempted to make, a chassis stock by using the complete action, floor hardware and barrel as the plug. Pillars allowed the floor plate and action to be screwed together. I’m assuming sheet wax or thin sheet foam layers covered with packing tape were used for barrel, trigger and magazine clearance. I never saw a completed stock, probably because it’s funny looking, but it could be worth giving a try if shaped foam blocks are added here and there to have a more common chassis appearance.

 

[BBob]

My understanding is his use of spruce & CF composite really revolutionized competitive biathlon stocks and kicked off the evolution to the space gun look of today.

That's my understanding as well. It is also my understanding that it forced the governing body at the time to start setting weight limits on the stocks since he was able to cut the weight so much over the previous stocks. His hunting stock was very well done and very well finished. I was fortunate to handle (fondle more like it ) them a couple of times and wanted one really bad. I would have paid a good chunk of change to get one at the time.

 

[Gobber]

TP -
Fiberglass Mold Stock Layup - For one-off prototype stocks, a mold layup is a ton of work and IMHO just not worth the work to set up. I much prefer designing a stock build to first perform to the specs I want it to do (rather than looking pretty doing it). I want it to meet performance requirements first, then look pretty doing it in later versions. Problem is - the next version usually has a completely new set of requirements.

What toggle action is that on your .22? Is that from a biathlon rifle? Very interesting.

Good eye! My favorite 'critter gitter' action is a somewhat modified Izhmash 7-2 Basic Biathlon. Being of Russian origin, there are very few stocks available outside the competitive biathlon world. So I do what I can with what I can make. On mine, the barrel is cut & threaded to an AAC suppressor, the barrelled action is fully Cerakoted, I adapted the trigger bar to use Anschutz trigger shoes plus a few other mods. As much as I would love to have an Anschutz Fortner Biathlon, it's just not in the current budget. Plus the Izhmash is just made to be modified. The machining is rough as a cob, but built like a tank. It's plenty accurate for my 'minute of squirrel' performance needs and is light enough to bang around in the woods with.

BBob -
It is very interesting to take a look at Eberle's influence on the sport of Biathlon back in the '80's. He had a revolutionary idea, ran with it, and changed the way Olympic regs governed the sport. And all in his 20's. Then went on to fly jets for several years before starting his company. A truly impressive yet still humble guy. Just watched an interview with him on how he got where he is now - guy is an icon!

 

[TaperPin]

TP -
Fiberglass Mold Stock Layup - For one-off prototype stocks, a mold layup is a ton of work and IMHO just not worth the work to set up. I much prefer designing a stock build to first perform to the specs I want it to do (rather than looking pretty doing it). I want it to meet performance requirements first, then look pretty doing it in later versions. Problem is - the next version usually has a completely new set of requirements.

Good eye! My favorite 'critter gitter' action is a somewhat modified Izhmash 7-2 Basic Biathlon. Being of Russian origin, there are very few stocks available outside the competitive biathlon world. So I do what I can with what I can make. On mine, the barrel is cut & threaded to an AAC suppressor, the barrelled action is fully Cerakoted, I adapted the trigger bar to use Anschutz trigger shoes plus a few other mods. As much as I would love to have an Anschutz Fortner Biathlon, it's just not in the current budget. Plus the Izhmash is just made to be modified. The machining is rough as a cob, but built like a tank. It's plenty accurate for my 'minute of squirrel' performance needs and is light enough to bang around in the woods with.

BBob -
It is very interesting to take a look at Eberle's influence on the sport of Biathlon back in the '80's. He had a revolutionary idea, ran with it, and changed the way Olympic regs governed the sport. And all in his 20's. Then went on to fly jets for several years before starting his company. A truly impressive yet still humble guy. Just watched an interview with him on how he got where he is now - guy is an icon!

I watched a few videos on biathlon rifles - very interesting. Your Izhmash is no slouch - are all barrels hammer forged and chrome lined? What a fun unique action.

Have you ever seen anyone use an industrial urethane paint with composite cloth? POR15 literature lists a tensile strength about that of epoxy and alludes to it being an easy to use substitute for epoxy, with more strength than polyester resins. It’s probably not practical for our purposes, but it did grab my attention. At one time I picked up most of a 5 gal can of por15 for only $40 and resealed it in mason jars - about 20% of the mason jars leaked enough to solidify the stuff and it’s down to the last few jars, which aren‘t long for this world. I will try to bag a test piece to see if it cures at all under vacuum.

 

[Gobber]

Love watching biathlon rifle videos. Do a search on the new Izhmash 7-7 if you haven’t already seen them. The one with the team doing push-ups is quite well done. Their biathletes don’t pull any punches.

I really like the toggle action for a suppressed .22 platform. Great balance of accuracy, weight & toughness. Fun to modify as well. It definitely can shoot better than I can, so the weak link is the loose nut behind the sight.

That POR-15 looks like some seriously good top coat. But at $300 a gallon new, I’ll have to stick with good ole West Systems. Is the stuff you have 2 part? Would be interesting to see if it will cure under vacuum.