Home Forums Hunting & Shooting Gunsmithing epoxy and synthetic stock?

Gents - I've bedded several walnut/burch stocks, but never a synthetic. I'm working with a Winchester take-off for a 70/670, and the main reason I'm considering at least the recoil lug area is because it doesn't have any sort of block, so it's just the steel lug resting on plastic. That seems like it's eventually going to be pushed/reshaped by recoil (9.3x62). Other than roughing and scoring for a solid bonding of plastic and epoxy, and a good cleaning and decreasing after sanding, any sage advice?

I have bedded a few. I drill holes at different angles and in general ruff up the bedding surface of the stock. This gives the bedding something to hold on to.

Are you doing an actual fiberglass shell and/or composite-foam stock or a plastic 'tupperware' stock?

Oh no, it's just a factory plastic stock. It's actually reasonably rigid, but as I mentioned, I don't like the idea of the lug only being in contact with plastic.

I also use a small propane torch and run it across the lug area to burn up anything slick( not more then a second or two) and then wipe it clean with MEK or Acetone,Never had bedding come loose.

I've done a couple of those with decent results. To start with, they need pillars installed along with the recoil lug reinforcement for any sort of decent results. But here's what I do for the rest of it:

From the top of the flat area behind the recoil lug mortise, four holes are drilled (from the top down) and short sections of 10-32 threaded rod (about 3/8-1/2" long) are epoxied in with ProBed 2000. I'm sure JB Weld original would be fine, also. Make the holes a bit larger than the O.D. of the threaded rod so the epoxy has room...don't 'thread' the rod into the stock. Make the threaded rod pieces short enough so that the top portion of the holes you drill for them remain open. In other words, the top of the rod will be below the flat area. That gives four good openings for the bedding to migrate into.

I'd also suggest bedding the rear tang. Be careful that the 'ledge' area of the action (ahead of the tang) does not contact the stock at it's rearmost part. This can in effect give you two 'recoil lugs' which you do not want. I've added a pic of that area.

On the Model 70's with the center action screw for bottom metal, I inlet a small aluminum pillar in the stock and use a short screw to thread into that rather than the action as an overly tight center screw is bad news for accuracy on the Models 70's that have that.

Rough up the areas where the epoxy will be and then clean it thoroughly with acetone. Make sure the recoil lug has at least .020 of tape on the front, sides, bottom and the 'ledge' of the action that can contact the back side of the 'flat' surface....if you look straight down from the forward part of the loading port you'll see the 'ledge' I'm referring to. The only area you want the lug to touch anything is at the rear...most important.

The two I've done this way are still in good shape after 8-10 years on WSM chambered guns. Both were done with ProBed 2000 bedding compound. Use a quality bedding compound, not some hardware store-cheapy-crapola that shrinks and moves after it cures.

Hope this helps. Use -Al

There's been many threads on this. You also aren't clear on what type of stock you have. What is it exactly? Injection molded: Factory "tupperware" or a "synthetic" stock, as your thread title says? There's a difference and different methods to be used with each..

Nothing fancy. Just intended as a backup for the wood stock I've been working on for it.

That stock is an injection molded (aka: 'Tupperware') stock, which is what my comments on bedding referenced.

Pillars with a 5/16" I.D. and using these 5/16" O.D./1/4" I.D. flanged sleeves glued into the pillars and long guide pins in the receiver will center the receiver perfectly and leave plenty of clearance around the action screw holes, which is very important. The Model 70's have an odd 1/4-32 thread for the action screws but Forster makes inletting guide pins for them. You don't want the action screws touching any portion of the inside of the pillar, not only for accuracy but for potential stock breakage. My preference is to not have the pillars making hard contact with the receiver, leaving them short enough so an adequate thickness of the bedding compound used covers the top of the pillars. That way, you have the receiver resting on only one material (bedding compound) not two different materials (bedding compound and aluminum).

Here's a few with the guide pins and sleeves for reference....hope this helps.

Good shootin'. -Al

Al, have you ever just used bedding material to "pour pillars". I do this a lot as in my mind you only have one type of material all the way thru the stock. You have one less thing to have "come loose" in the bedding. and nothing to worry about as far as thermal expansion goes.

I have in the past with good results.

For me, the 'sleeve' method addresses several issues at the same time and an aluminum pillar offers flexibility to make the pillar in a manner that works best for each particular project. Here's the rear pillar for my Sako A1 single shot...you can see that the epoxy retention grooves are tapered both ways to not only hold a good amount of epoxy but to have it 'locked' up and down. The center O.D. is smaller than the end O.D.'s which are used to locate the pillar in the stock holes. On the Sako, the rear pillar needs a notch which makes doing a poured pillar impractical, at the very least. The forward piece of the trigger housed has been milled a bit to allow as much pillar diameter as possible.

I can't stress enough the importance of a quality bedding material that has cured shrinkage numbers that work for what we're trying to accomplish. In general, the faster an epoxy cures, the higher the shrinkage numbers. After moving to Pro Bed years ago, my bedding jobs started to come around.

As far as pillar material, I don't use any extruded 6061 for pillars...only 6061 T6 tooling round stock. Extruded '6061'...while technically '6061', is significantly different than tooling 6061...you can see the difference when you're cutting it. When I've had to use extruded 6061, I let the pillars soak for several hours in acetone before installing them. It's amazing how 'dirty' the extruded stuff is compared to tooling 6061.

Just my 2 cents on it. Good shootin' -Al

I think the extruded is a 6061-T3 or maybe T0, either way it is softer than the T6.

Yes...while it's marketed and sold as T6, it's surely not T6 quality.

At the race car shop I 'work' at, we use a fair amount of 7061 tooling plate for high stress applications...motor plates, etc. This is a push bar quick disconnect that I whittled out of some 7061. It attaches to the 'chute mount and makes it really slick to push the car with a golf cart rather than pull it with a strap.

Drifting from bedding but here it is, for what it's worth. There's a lot of fabbed brackets and mounts under the tinware and dash panel!

cool, never worked with 7061, when I was in aerospace, I machined a lot of 7075 as well as other alloys

Better off buying a better stock than wasting time and money on a Tupperware stock.

not all Tupperware stocks are created equal. A Tikka stock is pretty stiff. Ruger American stocks, not so much.

Absolutely. I've got a couple of Lee Six injection molded stocks that are very stiff, for example. -Al

Compared to other tupperware stocks, this one strikes me as being pretty rigid. It's trigger guard inletting is a little shallow for the 670 metal, though, so some other work to do before tinkering with bedding.