$100k to Convert Tikka Stock to Rokstok While I (Im)patiently Wait

[Kenny Hart]

Why not integrate the cheek riser into the spacer? It could be held on with it being built onto the spacer at the rear, with 1 vertical screw and a plug up front, just like the factory CTR riser…all one piece.

Great question! Simply because it's 3D printed, which comes with its own complications.

That additional height would add A LOT of time to the print (more time for something to go wrong/tie up the machine for customer prints), would be a tall unsupported piece that could be subject to warping, and use more material.

I could mitigate some of those downsides by printing the part lying down, but I wanted the build layers and internal lattice structure to be strongest in direction of the recoil, as well as have a perfectly flat interface with the stock. It would look worse from a visual aspect to have the build lines running horizontally.

It also would have forced me to be more creative with how I would install a threaded insert for the recoil pad. I certainly could've installed them on the side adjacent to the recoil pad, but for pullout resistance I wanted the additional support of the thickness of the spacer to give far more "pull-through" resistance versus just having an insert 3/8 of an inch deep whose pullout resistance rests solely on the small amount of plastic surrounding it. Lets me really crank down the pad with those screws.

The separate cheek riser is a much easier solution, all it requires is an internal support for the clamp screw that you could simply cut a short section of PVC for, as well as the spacer shelf that I have the rear of it sitting on.

 

[Macintosh]

Makes sense. A second piece cheek riser designed like the oem CTR one, but extending rearward to meet the spacer, could be useful then. These kydex cheek risers all have problems—either they slip or they require extensive “rigging” to avoid slippage, they arent smooth, they add weight where you dont want it, require more significant modification, etc. The oem version is very simple and imo a functionally better solution…but they are totally 100% unavailable in the US and they dont address the butt height.

 

[Marbles]

I have no access to cool equipment, but I may give this a go with syntactic foam.

Have you thought about making the bottom flat to ride a rear rest?

 

[Kenny Hart]

Looks great to me. Since you have the tools at your disposal, I'd figure out something for the toe of the stock... To make it a little flatter .

I appreciate it!

I thought quite a bit about this. The toe is stepped up a bit because I was limited by the height of the recoil pad. The stock width required a "small" decelerator, which is only a little taller than the finished product. I have the pad dropped as low as possible on the stock and still have decent clearance for the install screw to go over the stock. It also gives a 1" height gain at the rear of the riser.

I also just didn't want a massively tall, heavy recoil pad in the rear.

The Tikka stock requires the small pad due to width, whereas the medium would let the pad drop lower, but I would grind into the metal internal insert before I could get the pad flush with the stock.

Carrying the current toe forward could certainly be done, and I agree would benefit the stock. It would just require cutting the bottom of the stock off flat and moving the spacer geometry forward at the bottom. As I described above, this would add a little more material and time, but not quite as much as an extended cheek riser to be much of a worry.

More so, it would require removal of the rear sling stud and bottom recoil pad mounting post from the stock. This would mean I'd need to drill and hammer in a cross pin or two through the stock and flattened toe extension to hold it at the bottom, versus the factory wood screw.

I may pursue that route in a future iteration, or maybe when I get ready to do my youngest daughter's stock. But for now, I needed to get it done, and hunting eastern whitetails/pigs I still like having a standard sling attached. We also just don't shoot at animals with a supported rear bag, as most are 100 yards, and more often closer.

I do like the idea of a flush forend and stock toe, but i hate the bulky, heavy, loud QD buttons that seem to have a tendency to pull out. A recess allowing access to a horizontal cross pin instead of the protruding sling studs could be a good alternative. That way I can attach a sling with paracord while still having it QD by using something like a Q sling devil. An avenue I plan to explore...

 

[Kenny Hart]

I have no access to cool equipment, but I may give this a go with syntactic foam.

Have you thought about making the bottom flat to ride a rear rest?

Yessir, literally just clicked POST on a response to HighUintas, and have some ideas about that!

 

[pods8 (Rugged Stitching)]

Having a flat bottom stock regardless of the recoil modifications would be nice. Here is a thought on it that doesn't require cutting the stock or rear sling stud removal (use it to anchor the new grip piece in the rear).

If I had a 3d scanner to create a nice model (fusion 360?) like you got there that is what I'd be inclined to try out.

While the PEEK is robust I think PETG would function just fine in the application don't you? It'd be far easier to print too.

 

[Kenny Hart]

Having a flat bottom stock regardless of the recoil modifications would be nice. Here is a thought on it that doesn't require cutting the stock or rear sling stud removal (use it to anchor the new grip piece in the rear).

If I had a 3d scanner to create a nice model (fusion 360?) like you got there that is what I'd be inclined to try out.

While the PEEK is robust I think PETG would function just fine in the application don't you? It'd be far easier to print too.

View attachment 784192

I like that idea a lot. I actually think the grip could stand to be a smidge longer for an adult, but pushing the bottom surface down as-is results in the grip screw recess coming to a sharp edge at the rear. With your suggestion, the grip could be integrated with the entire bottom edge and given additional height.

I initially thought this would be a bit too bulky looking for my liking, but with the stock in-hand, its really not that bad considering the trim nature of the original design.

And you're right, PETG would be easier and suffice, it's just not available for that printer. I could also use PC, but I don't think we keep any around. Normally just use ABS or PLA in that machine, which is why my boss just said to go ahead and use up the PEEK, as I think we bought it for a job that never transpired, or is complete.

We also have a BigRep printer, and one of our customers is a high-end custom automotive shop (I trained them on Joe Rogan's '69 Camaro) where they 3D print and install end-use interior panels with their high-temp material. Would also be a bit less expensive, just a rougher initial surface finish that I'd need to sand down.

A couple drawbacks that I foresee:

1. I am trying to take weight into consideration, and as it sits the stock is 35 or 36oz. So added material will only increase that...albeit not much. May make a difference to some.

2. With both attachment points being along a single vector, and the nature of the factory grip design having slight lateral play, it would probably require permanent installation via cross pin, epoxy, or both to remove what would be (to me) too much ability to rock left/right.

3. Obviously you'll need to give up the rear sling stud, or use it as the second anchor point and be sure to glue it in.

All in all, I like it. Nothing insurmountable, I'll just have to play around with it at a later date. I'll try to experiment with it on the second stock.

 

[Kenny Hart]

Makes sense. A second piece cheek riser designed like the oem CTR one, but extending rearward to meet the spacer, could be useful then. These kydex cheek risers all have problems—either they slip or they require extensive “rigging” to avoid slippage, they arent smooth, they add weight where you dont want it, require more significant modification, etc. The oem version is very simple and imo a functionally better solution…but they are totally 100% unavailable in the US and they dont address the butt height.

Agreed, the kydex holds solid here where I have it braced, but I'd never install one on a plastic stock without internal horizontal pillars because you can't tighten it down enough to stay put.

It's also far thicker/heaver than it needs to be, especially with the cross bolts, IMO. 3D printing thin parts also isn't ideal. An injection molded solution would be great, but someone else is gonna have to pay for that mold!

Ideally, we would just get any one of the rifle manufacturers offering a factory rifle with this/Rokstok geometry. Unfortunately, they have absolutely zero incentive to do so.

 

[pods8 (Rugged Stitching)]

I like that idea a lot. I actually think the grip could stand to be a smidge longer for an adult, but pushing the bottom surface down as-is results in the grip screw recess coming to a sharp edge at the rear. With your suggestion, the grip could be integrated with the entire bottom edge and given additional height.

I initially thought this would be a bit too bulky looking for my liking, but with the stock in-hand, its really not that bad considering the trim nature of the original design.

And you're right, PETG would be easier and suffice, it's just not available for that printer. I could also use PC, but I don't think we keep any around. Normally just use ABS or PLA in that machine, which is why my boss just said to go ahead and use up the PEEK, as I think we bought it for a job that never transpired, or is complete.

We also have a BigRep printer, and one of our customers is a high-end custom automotive shop (I trained them on Joe Rogan's '69 Camaro) where they 3D print and install end-use interior panels with their high-temp material. Would also be a bit less expensive, just a rougher initial surface finish that I'd need to sand down.

A couple drawbacks that I foresee:

1. I am trying to take weight into consideration, and as it sits the stock is 35 or 36oz. So added material will only increase that...albeit not much. May make a difference to some.

2. With both attachment points being along a single vector, and the nature of the factory grip design having slight lateral play, it would probably require permanent installation via cross pin, epoxy, or both to remove what would be (to me) too much ability to rock left/right.

3. Obviously you'll need to give up the rear sling stud, or use it as the second anchor point and be sure to glue it in.

All in all, I like it. Nothing insurmountable, I'll just have to play around with it at a later date. I'll try to experiment with it on the second stock.

"Run what ya got" but if you can print ABS and PLA you can print PETG which is smack in the middle. ABS would be fine too but is more warp prone. Unless it needs extended UV resistance I just tend to print things in PETG for functional parts cause its strong enough and has a high enough temp resistance it doesn't tend to warp in a parked car or such. ASA if I need UV resistance. PLA is just for nicknacks and iterative prototyping imho (cheaper and prints faster).

1) Yeah I hear ya on weight.
2) I hadn't really noticed the lateral play in the vertical grip, I'll have to check that out.
3) You don't need to give up the rear sling stud if you want it still, use the stud as the anchor screw. You may need to get a stud with longer threads potentially but they're available.

 

[Kenny Hart]

"Run what ya got" but if you can print ABS and PLA you can print PETG which is smack in the middle. ABS would be fine too but is more warp prone. Unless it needs extended UV resistance I just tend to print things in PETG for functional parts cause its strong enough and has a high enough temp resistance it doesn't tend to warp in a parked car or such. ASA if I need UV resistance. PLA is just for nicknacks and iterative prototyping imho (cheaper and prints faster).

1) Yeah I hear ya on weight.
2) I hadn't really noticed the lateral play in the vertical grip, I'll have to check that out.
3) You don't need to give up the rear sling stud if you want it still, use the stud as the anchor screw. You may need to get a stud with longer threads potentially but they're available.

Yup, it would be a good option but our Intamsys printers offer their own factory PETG, though they may have a similar material.

They are open source, which is cool, but you would need to dial in the chamber, bed, as nozzle temps manually. Our BigRep high temp is a good material, of I do a complete flat bottom integrated with the grip, I'll run that machine.

The play is barely noticeable, just a bit more so with the factory, and my vertical grips if you rock them left/right. I'm sure some stock/grip combos are rock solid by nature of injection molded tolerances. I suspect it will be a bit more noticeable with the bigger lever arm, though that rear sling still should hold it pretty tight.

I'm chasing whitetails this week, so I'll have to put off the computer play time until later!