Stacked Tube Nelson Concept

[Lane]

Updated first post with most recent model. Moved to a bore drop design with detents and to a 3/8 dovetail on the top tube to allow for a direct sight attachment or a picatinny adapter.

Original Post:

"Been messing around with this the last few days in CAD. Main goal is a lower cost nelson design with an integrating feed tube in the extrusion. Picatinny rail can be included as part of the extrusion so you can get a full length rail on the top or machine it down to iron sights (or down to completely round). Feed tube extension is threaded so it can be removed when attaching an HPA tank to clear the gauge/fill nipple. Barrel threads into the front of the body and extends into the body to just before the breech (breech drop design, bore drop would get a bit more complicated and costly). Molded pump handle, may do something similar to a magpul style pump and have mlok on the side/bottom, at least the bottom so a finger stop or vertical grip could be added. Could use the front frame attachment to connect a vertical ASA as well. Ideally keep the ability to attach a vertical direct feed. Lastly, with the extrusion it could be done with another 12 or so inches added to the front and a longer barrel so a 15-20 round spring feed could be added. Thoughts?"

Most Recent Models

[moving_target]

Iiinteresting

[RAZRBAKK]

Buddy, you are speaking my language.

[iamthelazerviking]

Super super cool. Maybe have removable detents, like the Timmy/Spyder version or something similar to ASP.

[Lane]

Going to look at an o-ring around the base of the barrel with a few slits in the groove to allow it to act as a detent. I think I've seen this done before. It'll also allow for the barrel to be pulled and swabbed without the O-ring coming loose and falling off.

[Grendel]

Looks nice but for Nelson's I would go for a Bore Drop. Easier to detent and if someone is interested in First Strike this could be a go to platform.

[Lane]

Certainly crossed my mind but there's really no effective way to get a first strike in there so I'm focusing it around round ball at the moment. The breech size is the same ID as a phantom so it should feed about as reliable.

[Chuck E Ducky]

Cocker frame it. Like a nice CCM 86* or a Benchmark slider.

[Lane]

Kicked around that idea but to keep cost low it would almost need to be a molded frame. The extruded profile for the body keeps it pretty quick to knock out but having to machine a frame would definitely drive up cost.

[RattManDu]

You could reduce your barrel to just an end cap that retained a freak insert and save some machining costs there.

[iamthelazerviking]

That's a pretty smart idea

[Lane]

You could reduce your barrel to just an end cap that retained a freak insert and save some machining costs there.

Interesting concept Ratt, only concern with that is there's nothing to keep the freak insert from sliding back into the bolt/hammer area. Since it's an extrusion at 0.850" ID there would need to be a way to capture the insert and keep it centered. If you had a freak bored barrel with some oring/spring clip grooves around it that could come in contact with the freak bore it may be enough to keep it forward while pumping.

[flyweightnate]

Look at Smalley retaining rings.

You don't need the insert to go all the way back to the bolt face, just within half a paintball. The goal is to chamber the ball, not the bolt.

In that amount of space, you could put in a spacer ring at .69" ID, clever use of some of the constant- section rings could secure it easily.

[XEMON]

Spring feed would work better on bore drop ...
totally in! Especially if you make a bore drop version ...

[Lane]

Good point on the springfeed, thinking about it more it may not be too difficult to add. I might mock something up later. Would also make freaking the barrel simple.

[Lane]

Changed things up a little with a bore drop insert setup. Adds one relatively simple part and can capture detents and a freak insert which is a plus. Also moved to a rounded top as there's enough meat on the top to tap it for 6-32 fasteners so if someone wanted to add a 3" length of rail for a sight it could be easily done. Can still add a direct feed easily with taped delrin inserts slide into the feed tube. Need to sure up the dimensions on it but looking at using an AR15 style sight post to hold in the front tube cap.

[Mr. Hick]

Getting more refined by the second. I like it.

Also, since this is an extrusion is there anyway you could tilt the end of the feed tube up 10* or so? That would make the "feeding with my 68ci tank because I forgot to bring my 9ci" way less painful.

[Lane]

With the feed tube extension being threaded into the main body it would probably be pretty difficult. Orientation would become an issue.

[Lane]

Mocked up some quick internals and a frame to get a better idea on component alignment and it looks like there should be plenty of room to have a vertical ASA option in front of the trigger guard. Will likely need to extend the main body another inch or so forward to give the pump additional clearance when a vertical ASA is attached. Not quite sold on making it Vertical ASA compatible. Pump right now is shown at 4.5" long so that could be shortened slightly as well to give more clearance. Lastly looking at a way to recess an extension spring in the pump/body to give the pump spring return.

[XEMON]

I like the bore drop version much better (with the freak insert inside)
What about moving the frame back an inch or so?
This would allow to route an in-grip bucket or lever changer much more easily (and a bottom air way/plug to the valve would be golden)

[Lane]

I like the bore drop version much better (with the freak insert inside)
What about moving the frame back an inch or so?
This would allow to route an in-grip bucket or lever changer much more easily (and a bottom air way/plug to the valve would be golden)

I'll be looking into that a little as the design gets more refined.

Threw some time into the internals tonight. Bore drop with a similar hammer weight and spring to a phantom. Hammer is similar to an Empire Trracer in style to hopefully avoid kinking. Bore insert is also symmetric so it can be inserted either way during assembly, has two detents though the back one doesn't do anything, just there so one's always ahead of the ball. With the bolt forward the paintball will sit about a 1/4" in the barrel.

[Lane]

Looked into feed options and barrel length of which 10" seems like a good compromise between length and performance, this also always for the pump to be in a location similar to other markers and not super close to the frame. With the added length it becomes possible to put a 10rd spring feed in the front as an option (could also do a 12 round rock back and cock without the spring and follower in place). Still working on the details but can probably use the spring feed follower and gate as the mounting points for a direct feed. Spring feed gate can currently be actuated from near the feed inlet or at the back of the marker above the valve. With a slight bevel cut into the spring feed follower it may also be able to serve as the stop/ramp for the stock class feed when installed. Lastly, might move the spring feed slot to the top of the marker and window both sides of the top tube. This makes it more ambidextrous and keeps the fastener/knob on the follower from being hit while pumping.

One last option is to cut a 3/8 dovetail into the top tube where the rail is mounted. This would be considerably more secure then 6-32 screws and if someone wanted to use a picatinny rail optic the adapters are plentiful and cheap.