Shrinking a Papoose

Status
Not open for further replies.
BigBlue 94

BigBlue 94

Member
Joined
Dec 5, 2018
Messages
3,311
Location
The Great American Prairie
The recent thread by @chicharrones has inspired me to make my small Marlin Papoose even smaller. The Nodak-Spud chassis is what I will be basing my build from.

So it will be a half stock chassis like the original papoose stock but will have a collapsing stock like the NDS or like on the Sig MCX.

I have a perfect stick of 1" thick 6061 aluminum which is only .005" thinner than the outer dimensions of the papoose reciever. So ill hog out the space for the action. It will accept AR15 grips. The butt plate will be made from the same aluminum and have a cheek rest that slides above the receiver when closed.

Hoping to start on it tomorrow. Any thoughts or pointers?

Also considering a free float tube Handguard but that will be after the chassis.
 
Interested in seeing your results. Just remember to keep the barrel at lest 16" long and also the overall length at 26" or more. Unless of course you plan on doing the paperwork to make a SBR.
 
12Bravo20 said:
Interested in seeing your results. Just remember to keep the barrel at lest 16" long and also the overall length at 26" or more. Unless of course you plan on doing the paperwork to make a SBR.
Click to expand...
Papoose is a takedown with a 16" barrel that i wont be touching with a cutter. Plus 6" for the receiver, and probably 2" for the stock and grip behind the trigger. So when packed ill have a 10" receiver section (2" barrel tenon) and a 16" barrel. But when the buttstock is in shooting position it should be at least 32" long. Im planning both a 12" and 14" LOP notch on the stock. With the stock collapsed all the way, it wont be comfortable to hold like a pistol at all.
 
chicharrones said:
Sounds like an awesome project!

Just as something to look at for other inspirational ideas, have you seen a Papoose with a modified folding stock?

https://www.rimfirecentral.com/forums/showthread.php?t=1156937

https://promagindustries.com/marlin-795-60-tactical-folding-stock-black-polymer/
Click to expand...

Yes I have seen the PM 795stock and mods. Pretty sharp but quite "large" compared to the NDS or MCX style. I think ive exhausted the papoose mod threads lol. Even browsed "backpack, survival, etc stocks" images online.
 
Last edited:
BigBlue 94 said:
Yes I have seen the PM 795stock and mods. Mretty sharp but quite "large" compared to the NDS or MCX style. I think ive exhausted the papoose mod threads lol. Even browsed "backpack, survival, etc stocks" images online.
Click to expand...

Gotcha. I should have figured you knew about that folding stock. :)

I'll give some thoughts about the Nodak Spud SRS-M stock.

First off, it is very precisely made and precisely fitted. Full appreciation to Nodak Spud for building a very good stock.

One thing to know is that the 1/4" thick stainless steel "wire" for the sliding portion is strong but flexible. It's a snug fit sliding through the bosses on the main stock. What I can't do when shooting this gun is pull the stock tightly into my shoulder like I can with a traditional stock design. The reason I can't do that is because the wire stock will flex, perhaps to the point of being permanently bent or curved. Which would probably mean I couldn't slide the stock back through those precisely fit bosses mounted to the main stock piece.

So, this makes me wonder should a thicker wire be used? 5/16" or 3/8" in diameter? I have no idea how much weight gain that would cause or if it would reduce flex enough to be worth the trouble.

Another wire sliding stock you're probably aware of is the Israeli modified Armalite AR7. The stock latches on both sides of the wire stock, which is different than the Nodak Spud. Plus, the wire goes to the middle of the "buttplate", which should reduce the potential for bending when shouldered. For shooting purposes, this Israeli gun would appear to have a stiffer stock.


Of course, there is the old M4 survival rifle, but it uses a one position stock lock instead of a 2 position lock like the Nodak Spud. Of note here is that the M4 and the Nodak Spud only latch the wire stock on the left side.
 
Last edited:
chicharrones said:
One thing to know is that the 1/4" thick stainless steel "wire" for the sliding portion is strong but flexible. It's a snug fit sliding through the bosses on the main stock. What I can't do when shooting this gun is pull the stock tightly into my shoulder like I can with a traditional stock design. The reason I can't do that is because the wire stock will flex, perhaps to the point of being permanently bent or curved. Which would probably mean I couldn't slide the stock back through those precisely fit bosses mounted to the main stock piece.

So, this makes me wonder should a thicker wire be used? 5/16" or 3/8" in diameter? I have no idea how much weight gain that would cause or if it would reduce flex enough to be worth the trouble.
Click to expand...

I took many precise measurements of the papoose receiver for an initial drawing. My piece of aluminum is 1"x3" and 3 ft long. It measures 1.012" thick. The papoose receiver outer dimension is 1.013. The outer dimensions of the operating rods (widest part of the trigger group) is .830. Its gonna be a svelte little piece! It will mount exactly like the original, using the trigger guard as a clamp of sorts. Might look into a metal trigger guard as this one is plastic.

As for the collapsing stock, I was planning on using 1/4" aluminum rod with spring detents on both rods. And maybe a thumb screw. Retention method is still up in the air to be honest. I might bump that to 5/16" aluminum rod. The rods will thread into the butt plate. I might try to incorporate a spare mag holder into the butt plate. The receiver end of the rods will run through a pair of sleeves 1.25" to 1.5" long on either side of the receiver. They will be part of a block that bolts to the back of the receiver chassis portion. The AR grip will likely mount on this block too. Might get one of those fancy grips with the storage in it. But for now I have a standard A2 grip.

There will be a 2" diameter or a bit smaller, half round aluminum cheek piece. It will slide over the receiver when collapsed like the black part in this pic I found.

1624126516731.png
 
Got started on the main chassis today.

Since the aluminum (metal) stock is the same width as the papoose receiver, I can focus purely on the inlet for the innards. I cut the 3x1 aluminum down to length on the bandsaw. I nearly cut out the shape as well, then realized I needed that material to clamp into my vise and keep it level. I took my chunk of 6061 over to the bench and double checked my measurements. Then applied dykem and started doing the layout. The main inletting is .725" deep with .435 and .470 deep steps on the ends where the screws will hold the receiver in. The inlet is .800" wide, but needs just a scosh of clearance around a couple pins that are proud of the .800 width. The inletting left .105" for the sidewall thickness. Plenty for this papoose.

20211231_173340.jpg

20211231_173347.jpg

Next up well be the holes for the trigger assembly and magazine well. Followed by the AR15 grips recess. Then I can finally cut the profile to it on the band saw and finish with the mill.
 
Made more progress today! It is techically shootable at the moment. The chassis itself is about 95% finished, save for contouring and deburring.

I was contemplating buying the aluminum trigger guard that is offered, then broke the flimsy plastic one today. Guess ill be ordering one for sure lol!

Looks like this will knock about 7" off the taken-down receiver, and 5" off the total packed length, since the 16" barrel is now the longest piece. And with the future stock piece collapsed and barrel installed it will be about 27".

20220102_172800.jpg

20220102_172937.jpg

20220102_173143.jpg
 
Today's project was getting the stock mount made. Started with a 2" long block of the same 3x1" stick of 6061. Hogged .800" deep out of the slot that allows it to sit down on the frame. Then drilled a pair of 5/16" holes and reamed them smooth. Then i set about adding some angles: 45° on the top side and 30° on the bottom and ends. Then did the D&T for three 1/4-20" cap screws. Overkill is my middle name lol.

20220106_173935.jpg

20220106_173958.jpg

20220106_174022.jpg

20220106_174038.jpg

20220106_174110.jpg

Cheek placement is gonna be pretty decent I think.

Next up well be the butt plate and rods. Latch mechanism will likely be a T-shaped lock with single button. It will be very similar to how an AR15 mag release works.
 
Did some work on the stock lock mechanism today. Also some profiling on the block itself.

Started by cutting a 1/4" wide slot deep enough to protrude into the stock wire bores a bit. Then i drilled a hole in the middle of the slot. Flipping the block over i bored that hole out to 3/8", leaving about .0625" of a shelf at the bottom.

Took a 1/4" SHC screw and turned it down to .190 and threaded it 10-24. Also threaded a hole in a piece of 1/4" key stock to act as the catch. Two nested coil springs provide the tension to keep the key stock in the locked position. The whole thing is similar to how a mag catch on an AR15 works

20220109_161116.jpg

20220109_161211.jpg

20220109_161250.jpg

20220109_161255.jpg
 
Got a bunch of parts yesterday: DIP fully assembled trigger guard and assembly, Magpul KOE2 grip, MP AFG (2? The bigger one) and a .625 gas block with picatinny rail to mount the AFG to the barrel as a handguard.

Should have progress to report tomorrow night
 
Today was mostly contouring around the pistol grip and safety area. Thats pretty well done now. DIP trigger guard is wonderful. Very short travel, crisp but not feather light. Much better than the plastic piece from the factory. I also cut the stock rods to approximate length.

The MOE K2+ grip had a beavertail on it that i cut off to fit under the stock adapter. It blends nicely and acts as an overtravel stop for the stock latch. The grip is at a steeper angle which is nice for a shorter LOP. The storage compartment is about 3/8" to short for a 10 round mag to fit, but i bet a 7 rounder will fit.

The other bit i did was modify and fit the AR gas block to the barrel. It was for a .625 barrel and the papoose barrel has a slight taper but is about .575". I ended up milling much of the unneeded material away and some off the top (bottom) as well as milling a slot for sight picture.

20220113_171350.jpg

20220113_171408.jpg

20220113_171400.jpg

Ive got a new front sight in my cart at brownells. The factory one is just plastic and kinda marred up. Ive also got a little 3 slot picatinny rail for the bottom front end pf the chassis. Incase i want to mount a flashlight or something. Gotts put something there as i screwed up on the trigger guard inlet length and need to fill that spot.
 
Got some more work done today. A few days ago i decided i didnt like the honky gas block as a handguard mount. And i wanted to mount a short picatinny rail to the very front of the chassis. So i did so, and mounted the AFG to it temporarily. The pic rail is 3 slots long. If i leave one screw just proud of the rail, the AFG slides on and is held in place by tension. I might modify the AFG to slide back farther around the mag.

Today i built the buttstock. I threaded the two rods on one end to 5/16-18 to thread into the butt plate. I also milled two slots in each to act as the slide stops. They are about 1.5" apart. They were quite stiff to slide until i found a .314" reamer in my box from an estate sale. The rods do bend a bit if i pull the gun hard into my shoulder, but thats not necessary to do with a 22.

Then i set about making the butt plate itself. Ive still got a bit of shaping to do on it, but its coming along. I do want to put a sling swivel on it too. I was originally gonna make a cheek rest, but it would put my cheek to high.

20220120_182530.jpg

20220120_182515.jpg
 
It's coming along! :cool:

With my Marlin Nodak Spud, I've been either just supporting the barrel with my hand or holding the "stock" just in front of the magazine. It just depends on my shooting position.

And the springy stock, best shooting results for me is to not add pull back pressure on the stock. A light hold seems to work best.

It's almost if the stock "sproings" the muzzle a bit when the trigger breaks, so I'm learning not to "preload" the stock on these little rimfires with wire stocks. :D
 
Last edited:
Couple more hours down yesterday. I spent most of it contouring the butt plate. It looks good enough, but i wish i could do some 4th axis milling to get compound angles. I can only do it on x and y, and kinda manually on z. I suppose i could mount my rotary table to do some on the xy diagonal. Seems like too much work to set up.

The buttstock wires are just barely off from alignment with the locking block. Meaning when i close it, it gets tight about an inch from closed. The rest of travel is great. I tried relieving the locking block a little but fit is diminishing with each attempt. So ill live with it. As you can see, it still is under the 16" length of the barrel.

I also cut a notch into the back of the AFG, and slid it back around the mag a bit. Even with the AFG and not-quite-closed buttstock, its under 16". So this is permanent.

20220123_111213.jpg

20220123_111222.jpg

20220123_111243.jpg

20220123_111310.jpg


20220123_111437.jpg

20220123_111418.jpg

Im not real concerned with the bendy stock. Its meant to be light weight and i just use the butt as a third point of contact rather than a brace against recoil.
 
Just spent a couple hours sanding and filing on it to smooth put all of the edges. It feels real nice now. Also loctited the stock rods into the buttplate.

Time to start pondering color. I have duracoat in greens, browns, black, tans, gray, and stone. I think ill do a grassy type camo on the whole assembly, receiver and barrel included: sans the grip and AFG.

Similar to the pattern i used on my R700 AICS chassis probably.
index.php
 
@BigBlue 94 ....

Well done. I found you here after the blurb on @chicharrones thread. I will be following your lead if I don't get a lead on one of them SRS-M stocks. My papooses are played with already (just dropped pics on chich's thread), but I have a stainless 880 in a polymer stock that will get this attention. You mention building a tube handrest. One of the papooses pictured on the other thread is running RangerPoint Precisions Keymod, Extended Barrel Nut.

Expanding on the RP extended barrel nut thing: I am ISO a stainless papoose barrel. Working with the RP handguard, I decided that I will eventually Form 1 with a barrel nut tube over <12" of barrel. Some baffles installed in the barrel nut tube will complete an integrally suppressed rig.
 
I saw the RP handguard/barrel nut. Its pretty neat. I dont remember if it was too pricey or out of stock or what. Something turned me off. Other than the keymod portion, making one on the lathe would be super easy.

Ill check that thread out.

I have seen papoose barrels for sale, but out of stock. Ive also seen the receiver sleeve that converts a regular marlin 70/795 into a papoose.

I thought about an integral suppressor, and still may, but not at this time. That would be one heck of a stalking rig.

Since my last post ive done a couple small things and some sanding edges. I added a pair of traditional sling swivels and added a notch on each stock rod to latch when closed. I finally got my spray booth ready, just have to drill a 4" hole in the wall for the dryer vent im using for the exhaust. Then i can duracoat this and about 3 other rifles.
 
Finally getting this thing into the paint booth! I shot it with Dura-fil on Sunday and some Duracoat of my own mixing today. The color is 5 parts Duracoat Stone and 1 part Magpul FDE with some flattening agent thrown in.

It will get some Magpul OD green and FDE and some woodland brown camo accents.

Im not very pleased with doing large areas like this with the airbrush. Hard to get a good coat and takes forever and ever.

The exhaust fan on my homebrew booth crapped out on the first sesion too.

20220310_140052.jpg
 
Status
Not open for further replies.

Similar threads

I
  • Locked
Building a faux-Krinkov
Replies
10
Views
3K
Ian
I
Back
Top