Custom-built Top-folding Shotgun Stock?

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pope_face

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Alright, I'm aware that I may get flamed for bringing this up, but hear me out. I just bought a used Ithaca Model 37 from a fellow CGN'r, and I've started toying with the idea of a "tactical" build... ok, well maybe I bought it with that idea already in mind. I won't get into details here (unless someone asks), but I like the pistol-grip with top-folding stock look, a la the SPAS-12. The issue is, the only stocks available are either the standard stock or a pistol grip (or a pistol grip/side-folder by Choate, and I'm not too keen on that one).

So, what my question to you is, is it possible to build a SAFE, working, top-folding stock, using a synthetic pistol grip? I was thinking of drilling sideways through the pistol grip, behind the receiver, and mounting the horizontal upper part of the folding stock from that. Because the Ithaca has a bottom-ejection port, the two sides would end up on either side of the receiver when folded, without interfering with ejection of spent shells. The rear part of the stock (which will go against my shoulder when in use) can then rest on a heatshield over the barrel. Again, like I said, think SPAS-12.

Now, I'm aware that there are dangers inherent with any "inexperienced" firearm modification, which is why I thought of asking on here before jumping in. However, I'd want to err on the side of caution and do it well, not just use wood screws on a couple pieces of aluminium bar and away we go. I'm thinking of grade 10 bolts, reinforcing the hole in the pistol grip (perhaps a steel tube cut to fit, with the bolt through the center?), and designing some sort of locking/quick release mechanism to secure the stock in the up or down position. I also know someone who builds custom knives for a living, so I'm considering getting him to make the sides and shoulder "plate" for me, either out of mild or high-carbon steel.

I'm willing to take the time and effort to get this done right the first time, so it works well and looks good. This is less of an "Is this possible?" thread and more of a "What will it take to do?" thread, so I'd like to hear an actual reason for an opinion, not just "That sounds good/bad/insane." Thanks in advance...

Fil
 
It's certainly possible. And I like how you're already thinking about the details which would either make or "bubba" such a project. How the catches and stuff at the hinges work out will make or break this. And since you're only modifying an easily replaceable pistol grip and adding on parts you're not doing anything to the actual gun that will ruin it. So the risks of a total loss are very minimal.

Draw it out, think it through, mess around with some mockups made from hot glued thin plywood such as door skin or hardboard to see how things will work out before commiting to metal.
 
Rider: Thanks for the support... using thin plywood is a great idea, and I actually happen to have some laying around. I was considering making a template using some posterboard and using that to transfer it to metal, but I'll give the cheapo way a go first.

And yes, the only potential damage would be to the pistol grip, but the shotgun currently has the standard wood furniture, and apparently a pistol grip (assuming I can locate one) should only be about $25-$30, new. I called Reliable Gun this afternoon, so they're going to see what they can track down, and they seemed to think it was a workable idea.

As for the actual design... there are a few possibilities, but I think the best solution would be to use two thicker pieces (maybe 1/4"?) of bar stock, each about 12" long and 2" wide, and use those to make the sides of the stock. That way, when the stock is folded, the length of the stock will sit along the sides of the receiver, instead of covering the top. If I use a few bolts both near the buttplate and pistol grip as cross-braces, they should reduce lateral movement and any torsion of the buttplate. The thicker material should also reduce the chance of shearing off one of the bolts connecting the sides of the stock to the pistol grip or buttplate, and I could probably lighten the sides by cutting holes in them without losing a lot of strength/rigidity. The only real catch will be designing some sort of locking mechanism to keep the whole thing either open or closed, but I've got a couple ideas for that too.

One quick aside: I apologize in advance for long, convoluted posts... it's partly to share my thoughts/ideas on the project, and partly to get them in order. I've always found it easier to figure out my thoughts by trying to explain them to someone else.
 
1/4 inch material would be way overkill and overly heavy to boot. Sheet metal of around .090 would be fine. You just need someone to put creases in the material at some points to form stress carrying stiffening ridges. This may have to involve a sheet metal shop or with some effort you could make up a creaseing die and cold form the creases yourself using a good bench vise. If the sides and web of the channel were made from separate pieces and then neatly mig or tig welded together to form the final shape it would look tidy and factory made.
 
Thanks for the suggestion... sheet metal was actually my first idea. I was considering getting a layout done on a flat sheet (maybe 5"x12") and getting a rectangle cut out of the center, wide enough to fit the reciever and about 9" long. Then, get the two long sides folded down to make an inverted "U" shape, and that would be the basis for the stock.

The reason I don't want the stock to go over the top of the receiver is so that I could mount ghost rings or a red-dot reflex sight, and not have the stock interfere with them. However, this means that the middle section of the stock needs to be solid enough to prevent sideways flex and torsion without any crossbracing (As an aside, I apologize if I use weird terms in my descriptions... I've got a construction/mechanical background that I'm applying here).

Do you think that using stiffening channels along the sides would make it strong enough to prevent flexing? I agree that going that route would certainly give it a "factory-made" look, and it would be far less bulky than an extra 1/2" of metal out the sides. As for welding... I'd rather get it done out of a single sheet, if I can. It might be a little more expensive to buy a sheet big enough to do the entire layout, rather than just bar stock, but at least I can save on getting the welds done and just have it bent instead... I don't have the equipment and training to weld this well enough, and I think having it done by a professional will kill this project in terms of cost.
 
Luke: Thanks for the support... as for photos, I'm pretty sure there'll be lots of those. If there's some actual interest, I'll do a write-up on the whole thing, although there doesn't seem to be that many people who want to "tactical-ize" their Ithacas. But, maybe that's just due to a lack of accessories. To be honest, it hasn't even arrived yet... Canada Post tells me I likely won't get it until Tuesday, so I can't even start taking measurements or testing out possible setups until then.

I also found out that two of the shops in town can't get ahold of the pistol grips... I'll call around to the other places, but chances are looking pretty slim. I'll try getting one online or on the EE, but even then... I may have to put one together myself. More cost and a bigger hassle, but the upside would be that I could incorporate the stock into the pistol grip, as well as building one that fits me rather than a "one-size-fits-all". In any case, I don't plan on giving up on this project yet.
 
A U shape, or more accurately a |_| shape, will not fit over most red dots. But if you can find a pistol red dot that is no more wide than the receiver you could mount it to a short picatinny rail and just leave a 3 to 4 inch long hole in the web between the two sides of the stock's welded channel. That way when you fold it up and over the sight and rail will align with the slot in the web.

The other option that I sort of like would be a nicely made up ghost ring and matching front bead on a raised platform. This would make the setup similar to a slug gun but with a folding stock. The ghost ring has the advantage of being smaller and not needing batteries and it's almost as easy to get a quick sight picture as a red dot. Best of all it doesn't wash out and get super hard to see in daylight like red dots. Having done some IPSC shooting this past summer I saw a fair number of shooters that had to pause while re-finding the red dot in their sight. When the sun is hitting the open frame red dots just right it seems to be a real problem. The tubular "scope" style red dots don't seem to have this same issue. But they are generally going to be wider than your receiver and would make it so that the stock isn't as neat a fit. So that's why I suggest the ghost ring instead.
 
BCRider said:
But if you can find a pistol red dot that is no more wide than the receiver you could mount it to a short picatinny rail and just leave a 3 to 4 inch long hole in the web between the two sides of the stock's welded channel. That way when you fold it up and over the sight and rail will align with the slot in the web.
Click to expand...

That was exactly what I was going for, although I suppose I didn't express it quite so well. I appreciate the tip on pistol red dots vs the "standard" ones... I hadn't considered them being wider than the reciever, but it is a good point.

As for why I want a red dot sight... partially for looks, partially to try one, and partially because I think it might help with getting a bead quicker. Than again, I've never used a red dot sight or ghost rings, so I can't say for certain which is better. However, I would like to get a pair of ghost rings as well, and a quick-release mount for the red-dot sight. I'm not planning on smashing the sight, but in the event it happens I'll be able to pull it off and use the ghost rings without too much trouble. Yes, it is a bit of a "mall ninja" setup, but I consider my rifle to be my "proper" sporting firearm... this one is part play, part defense, and part challenge.

And the Picatinny rails... you hit the nail on the head there as well. I'm considering one over the reciever and one at the front of the barrel, with a space between the two. That way, I can mount my sights to the barrel and receiver, and hopefully the buttplate of the stock will lie flat along the barrel, in between the two rails.
 
Found a web site that has a bunch of pics and .pdf files of the Spas12. Might be good to help with picturing what and how things work.
http://spas12.com/

I've always loved the Spas12. I got to shoot one before they were prohibited. I fired a couple of rounds with the stock extended and a couple shots one handed with the hook around my arm. Tons of fun. Politicians are bastards for prohibiting the Spas12.

gruppo_di_big_boomo.jpg
 
You might be able to find a folding stock for another make/model that could be modified/cannibalised for some of the critical components (hinge, lock...) and made to work in your application... I would be wary of trying to add a pivot to a plastic grip assembly. Plastic components are often hollow and structurally compromised if altered. Manufacturers tend to want to use the minimal amount of material to keep costs down and moulded plastic parts are a great example of this.

I would be inclined to try and fabricate a new grip mount (likely MIG welded out of mild steel pieces) that would incorporate the hinge assembly and have a provision to mount a grip of your choice on it. There are tons of aftermarket grips available, you would simply have to chose the type (AR,VZ,AK,SwissArms...) and figure out what is needed to mount it to your stock hinge block.

If you are a "handy" person and have some means of fabrication available to you then it likely could be a fairly easy project. Anything is possible if you throw enough money at the problem... Unfortunately many of us have only pocket change at hand. If you have to outsource fabrication then things get expensive fast!

It's a shame you live on the wrong side of the country... I like tinkering with these kinds of projects and have some basic fabrication tools at my disposal.

Some simple fabricated parts (mostly mild steel) made with a MIG welder and grinders/hand tools:

My54.jpg


click.jpg


gasblock.jpg


bits.jpg


Mockup3-1.jpg


minigrinder.jpg


My55.jpg


mag.jpg


My51.jpg


I shudder to think what this sort of stuff would have cost to have made, but my time is virtually free to me and material costs are nil as most of it is scrap metal offcuts.

Good luck!
MB
 
Good lord. You can get the folding stock on ebay for $700.:eek:

http://cgi.ebay.com/SPAS-12-FOLDING-METAL-STOCK-Shotgun-Orig-Marui-Franchi-/170566436655?pt=LH_DefaultDomain_0&hash=item27b68d472f
 
Mercury: I appreciate the link... I took a quick look at one of the exploded views, and it seems that the stock just uses removable pins to lock into place, but I'll have to take a better look at it. I'd rather not use pins like that though... what I'd really like to do is use some sort of spring-loaded catch to lock the stock to the pistol grip, and the buttplate to the stock, when it's folded out. This way, I don't have to worry about loose parts, and I know that as soon as I flip out the stock, it's ready to use and won't move unless I want it to. I'm thinking of something along the lines of a typical gate latch... as I'm folding the stock down, the pin will engage the latch, forcing it open, and once the stock is in the "fully extended" position, the latch will snap back shut, locking the pin in. Holding the stock in place when it's folded shouldn't cause as much of an issue... a simple strap across the top of the barrel with a snap on one side will likely be more than sufficient. Folding up the stock, or holding it there, won't be as critical as extending it. Assuming I can design and assemble it properly, extending the stock might be as simple as undoing the snap and flipping it back.

I'd like to mention that I appreciate the support you guys are giving me on this project, although I find it amusing that three of you (one person PM'd me) are local to me. Perhaps I'll have to make a trip to the range and let you guys have a run with it once it's done, assuming it all works out.

EDIT: Wow... I was originally posting to Mercury's first reply, but the additional posts are a nice surprise...

EDIT 2: Mercury: That's a great video, I didn't realize that it fold/unfolds so easily. I'll have to take a closer look at the parts diagrams to see how that's done.
 
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MB: I appreciate the offer and the support... I actually had a local CGNer contact me about this project, as he owns a machine shop in the area. I'll still end up paying him for the work done, but his price is reasonable (for me), and I'll still plan on doing most of the work myself (sanding, painting, assembly).

As for mounting it in a synthetic, aftermarket pistol grip... that idea is looking like it won't happen anyway. It seems I can't get one from any of the shops, and I doubt the EE will have one.

SECOND EDIT: I've decided to look into getting the top part of the pistol grip machined out of metal, so that I can bolt it to the reciever, attach the folding stock to it, and then mount a pistol grip from an AK, HK, AR, or any other rifle that mounts the grip below the reciever, right behind the trigger. Checking the EE, I'm seeing grips available between $8 and $50, depending on what it's for and what it's made out of. So far this seems like the best option of getting a pistol grip.

The idea of making up a mount to fit a grip off an AR or Remington or whatnot is an interesting one, although I'd have to make sure that the distance between the grip and the trigger isn't too much. The other downside of using an aftermarket folding stock is that they would all be designed for a side ejection port, and would most likely sit along the top of the reciever, not the sides. If I can come up with a working design specific to the Ithaca, I can have the stock sit next to the receiver when folded up, rather than on top. In the long run, it might not make much difference, but it would prevent interference with sights, and I think it would give it a bit of a slimmer, "cleaner" appearance. But... I've yet to do it, so I could be wrong.

BTW, I like the work that you've done... did you build that CZ from scratch, or is that an actual working firearm that you've modified?
 
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What you should do is get one of these from here:
http://www.redwolfairsoft.com/redwolf/airsoft/Accessories_Grips_and_Stocks_Shotgun_Sniper_Rifle_KTW_SPAS_Custom_Metal_Stock_Set.htm

KTW-4571383526228-1L.jpg
 
If I ever get an Airsoft gun, I'll consider it. Till then... I'll stick with one that won't fall apart under the recoil of a 12 gauge.
 
Ah, now that makes more sense... that actually is pretty close to the design I want, with a couple differences: I want the long part of the stock to be upside down compared with the SPAS, so that when it's extended, it'll be a |_| shape, with the cross-members at the bottom instead of the top. That way, when I fold it up, the two sides of the stock will end up next to the reciever, and the cross-members will end up against the top of it. I'll probably do a slightly different shape and design of the sides as well.

I do like the "buffer" he talks about in the video though... I wonder if I could work something like that in.
 
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