Sliding vs. folding stock

I'm just putting this out there,
A Grizz-mag with a MP5 style collapsing stock and GASCAN's drum mag and I think we would have Tacticool shotgun winner of the year.
Just sayin' I'd be down.
 
hkr, any decision? can't keep us waiting like this man.... hahaha. i vote sliding.

i love those S&J adapters and how they put the stock in line with the bore.
 
I'm still here, was just trying to put something together in solidworks and I haven't made a model this complex before so it's slow going.

Well, there are certainly some good options already out there. But, I enjoy the design build process so I'm still going to try to make my own. And I think it will be sliding. Hopefully with an integrated spring/shock to dampen recoil. I like the look of stock in line with bore as well, so I'll try to make that happen.

I have the adapter block roughed in, now I have to design the slots for the stock bars and contours to fit grip and receiver. Is there a common grip type out there that mounts with just a flat plate instead of the notched AR setup? Would make the milling much easier. I'll post up a pic once it starts to look like something.
 
This is what I have in mind as a rough layout. I may have to notch the bar so it can go further forward without blocking the ejection port to have enough length to match the original length of pull.

stock%252520mockup.jpg
 
The oal will be 26" either way, so the choice is more about aesthetics and performance than length.

This is what I have so far. There will be a plate screwed on the bottom to cover the opening and mate with the grip, and two on either side of the wider part at the back to create slots for the bars to slide in.

The contours match the receiver where they meet, so it should look pretty good.

stock4-1.JPG


stock4-2.JPG


I'm thinking of making the recoil spring attached to the pins that will come out either side to lock the sliding bars at different lengths. These pins would slide in slots cut lengthwise in the piece pictured above. Except for those pins to hold the bars firmly, it might create too much friction to slide... unless they were tapered, then they would eliminate any play without too much side force. Any thoughts on that? ...I'll try to get a picture up haha, hard to verbalize.
 
I'm thinking of making the recoil spring attached to the pins that will come out either side to lock the sliding bars at different lengths. These pins would slide in slots cut lengthwise in the piece pictured above. Except for those pins to hold the bars firmly, it might create too much friction to slide... unless they were tapered, then they would eliminate any play without too much side force. Any thoughts on that? ...I'll try to get a picture up haha, hard to verbalize.

kind of like a ball detent/retainer system? that is what I am getting out of it....

if that is the case, in theory, it sounds like a wonderful idea... I would be concerned about the friction while sliding, then the stock collapsing under heavy recoil, slamming your hand between the pistol grip and the butt plate... haha

the notched bar looks like a great idea, that will give you way better LOP, but not interfere with the action.

in terms of the grip being notched, IIRC the CZ 858 grips are flat (don't have mine here to disassemble) , not notched like the ar. I'm sure the one of guys over in the red rifles section could post a picture of the bottom of one.

looks great so far !
 
Yeah I'm not sure that would be the ideal mechanism either, but can't think of another way to do it. If it was just on the butt pad part between the slides that would work, but then the oal would increase. My understanding is the oal would be measured to the end of the adapter block, because you could theoretically unscrew the sliding part and fire it as pistol grip only?

Edit: Or what if the part that holds the sliding bars on was attached to the piece that holds the grip on, then it could be shorter than 26" with just the adapter block and no grip or stock. Because it can be fired with the factory stock removed as well, just not fired effectively or without hurting yourself, and this would be the same. Does anyone know the technicalities on this?

Here's a few more, a bit further along.

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stock%252520assembly%252520bot%2525206.13.11.JPG
 
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hkr, on my way to work (hour drive haha) I had a brainstorm....

for the locking mechanism, using a spring loaded ball retaining system, angled towards the back, one on either side, mid height of the adapter.

if you drilled a hole through the top and placed a pin, with a spring at the bottom, that when depressed allowed the ball detents to be pushed towards the middle of the adapter, which would allow the stock to slide forward.

i wish i had (and knew how to use) a drafting program to show you what I mean.

Look at a sage 870 sliding stock for a rough idea.
 
ms paint works great for getting ideas across! No need to make it look pretty, I've done lots of rough sketches in there before.

This is the sage stock:
ts870cl-lg.gif

ts870op-lg.gif


I guess it's functionally the same as what I'm going for, but hopefully mine will look more smoothly integrated with the rest of the gun.

I think I get what you mean, and that was more or less what I had in mind. Except instead of the round bars with notches on the bottom like the sage, mine will have flat bars with pockets on the inside and pins coming out of the adapter block. And I had the same idea for a pin that you would depress to move the side pins in, but this would probably be on the back of the adapter block rather than the top so you could press it with your thumb one handed.

I'm going to redraw this with a shorter block so I can build the recoil spring into the butt and keep the length at 26", and the bar slots/grip attached in such a way that you can't remove the stock without removing the grip, to keep it legal. Hopefully rivets are acceptable for this, I don't have a welder. Now to find a way to hide the rivets to keep it pretty...
 
Here is another interesting one:

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27106.JPG


I couldn't see a good way of having it lock up solid when fully extended if I were to notch around the ejection port, so I'm running the bar lower like in the sage and the one above.

Here is the new adapter block, it is made from 3 pieces milled out of 3/4" plate, plus the thinner end piece, held together with two screws going through all pieces. You can see the slot on the bottom that will hold the grip adapter plate. Also the holes into the inside of the sliding slot that will hold pins to lock the bars in place. These pins will be released by a third pin running perpendicular through the small hole in the back, by having wedge shapes on all 3 pins.

stock%252520assembly1.JPG


stock%252520assembly2.JPG


stock%252520assembly3.JPG


stock%252520assembly4.JPG


stock%252520assembly5.JPG
 
that adapter is looking good hkr! it looks like it will keep the lines of the shotgun, very smooth.

that previous picture of the high tube just interrupts the clean lines too much.
 
Hello Mr. hkr:

Sorry to hijack this thread but would u be able to machine a small piece of alu or delrin plastic (adaptor block single piece) so I can adapt an ATI stock to an Ithaca M37 ?

Please ?
 
Thanks, smooth lines is what I'm going for!

Sure, I can machine anything if you pay me enough ;). Not having that stock or shotgun I wouldn't be able to measure them to create the model, so unless you can make a 3d cad model for me, I don't think it's realistic. Even if you got the measurements for me, the design process takes a while and would make it prohibitively expensive unless you're spreading that cost across multiple units. That said, if this is a simple piece, send me a sketch and maybe I can help you out after I finish the few projects I have on the go.

Mentioning delrin got me thinking... Maybe I'll do the prototype out of polycarbonate or something similar. Way easier to machine and half the weight of aluminum. And then just see if it holds up to the recoil. And hope it doesn't shatter and take out my eyes :eek:.
 
if you're going to make a top folder..

please model it off the SPAS12 .. all boxy and angular.. the ATI and other style top folders look like chicken drumsticks

top folders arent comfortable, nor are they supposed to be.. make it ###y

what he said, not practical but awesome
 
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