Gunsmithing Making a fore-end stiffer.

mdesign

Gunny Sergeant
Full Member
Minuteman
Nov 2, 2004
2,134
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Nebraska
I need to stiffen up the fore-end of old fiberglass stock that I have. Its pretty flexible and you have to be really careful when running a bipod.

I was thinking about in-letting a groove in the barrel channel and gluing in an aluminum tube.

Anyone found something that works well?
 
Re: Making a fore-end stiffer.

carbon fiber composite rods or tubes will work far better than aluminum alloy. It has a higher modulus and lower density. For a given weight of material, the composite will be much stiffer. To match the stiffness of the composite you would need a lot more aluminum alloy.
 
Re: Making a fore-end stiffer.

In addition to carbon arrow shaft I have used a length of all thread unlet and then fully bedded in place. Added a bit of weight up front to a too light rifle and stiffened it right up.
 
Re: Making a fore-end stiffer.

Wrap 2 layers of tape around your barrel. Electrical tape. . .

Wet the stock with resin and soak a piece of 40oz twill weave carbon. Squeegie the excess using a deck of cheap playing cards.

Hose your barrel with release agent.

Assemble and clamp the snot out of it.

Allow to Cure.

Pop it out, sand the edges down, and it'll be rock solid. Better yet, gut the inlet and continue it under the lug and down the receiver.
 
Re: Making a fore-end stiffer.

One or twice. . .
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Re: Making a fore-end stiffer.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: C. Dixon</div><div class="ubbcode-body">Wrap 2 layers of tape around your barrel. Electrical tape. . .
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Or 50 layers, if you want just a <span style="font-style: italic">little</span> extra room under your barrel.
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Re: Making a fore-end stiffer.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: C. Dixon</div><div class="ubbcode-body">One or twice. . .
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damn, i've been wanting a starbucks at our range for a while now. i never thought about having a gas station there though.
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Re: Making a fore-end stiffer.

One thing to remember when working with carbon fibre you need to use a breathing filter as the carbon dust is very hard on your lungs. Apparently, your lungs do not expel the fibres as they do not see them as a danger.

Here is a source of preformed carbon fibre http://www.dragonplate.com

wade
 
Re: Making a fore-end stiffer.

Check out fibreglast.com for the carbon fiber too. You can also get it already impregnated with resin. Just add heat to cure it. You are going to want to use epoxy resin with carbon.
 
Re: Making a fore-end stiffer.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: aron</div><div class="ubbcode-body">Check out fibreglast.com for the carbon fiber too. You can also get it already impregnated with resin. Just add heat to cure it. You are going to want to use epoxy resin with carbon. </div></div>

"Pre Preg" or material that contains the resin is great stuff. The saturation is already taken care of for you and the ratios are spot on. (generally 1:1 based on weight. If its a lb of fabric, use a lb of resin)

The issue is its an oven cure process. Depending on what type of resin its saturated with will drive the curing temp/time.

There's no certainty however that the rest of the stock will tolerate the heat. Some of this stuff is quite high. It's not as simple as warming it up with a hot air gun or tossing it in the cerakote oven.

The other issue is storage. Leave it out and it'll deteriorate (harden).

I personally don't use prepreg. Instead I lay the material out on a glass plate, pour resin over it, and squeegie with a deck of cheap playing cards to work it into the fibers. It's more effort, but the resins I use will cure at room temperature.

The big trick is getting the barrel channel right. If you cut too deep and don't keep the barrel on the waterline it'll form a mechanical lock that's a devil to peel apart.

You also need to take measures to ensure the liquid resin doesn't creep back into the bedding area.

I then belt sand it near flat to the stock and block sand the rest. Polishing up the carbon starts with 600 grit, working up to 1500, and finally with a wheel using the "ruje".

Then its polishing compound like you use on paint. Gotta be careful not to burn the resin though.

It's a bit of work, but they do look pretty cool. Getting the fabric to "lay right" with the weave parallel to the stock is prolly the hardest to do. It's easy for it to twist up on the bias of the fabric.

40oz twill works good for me.
 
Re: Making a fore-end stiffer.

I used Loc-Tite multi-purpose stick putty to stiffen up the fore-end on my 700 SPS stock. Just used a sanding drum on the Dremel to scuff the walls of the voids and a cutting wheel to make a few slits in the partitions that ran through the section I was filling in. Kneeded up the putty stick and pressed it into the voids, being sure to get some to ooze through the slits to really lock it in. It did the trick nicely, enabling me to shoot off a bipod without the fore-end flexing up and touching the barrel.

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