Tricks for moving feedneck?

[flyweightnate]

I'm "fixing" this old Sterling, and one of the things that needs fixed is the space between the bolt face and barrel. So I'm moving the feedneck forward 0.8".

Anyone have special "tricks" for a job like this? I'm going to plug the old feed, drill the top tube to trim the feedneck (thinking of wrapping the drill in paper or tape to protect the bore), ream the top tube to size, flex hone the top tube, then drill for a CCI feed.

One challenge is that the CCI feed screw lines up over the barrel, of course... and there's not much meat there. I've never been a rock- back guy, but I guess I might need to learn... unless anyone has cool suggestions. I'm only measuring about 0.080" from the outside to the barrel.

[scottieb]

I wonder if it would be easier to have the bolt itself in a different position?

[flyweightnate]

I lengthened the bolt, so I wouldn't have the giant gap between the bolt face and the barrel. The ball has to travel almost an inch before hitting the back of the barrel, which seems... dumb.

[Jordan]

Drill a mounting hole near the back of the CCI feed, in a spot that gets covered by the feedtube when installed? Or closer to the front, with a countersink to allow paintballs past the screw head. Sort of like a reverse feedblock setup, but still mounted rock forward.

[Siress]

Remember how the gargoyle had that threaded stud for the front frame screw? That, with something like this https://www.mcmaster.com/product/98002A406 replacing the usual screw.

Not sure how best to get the threaded post in there, though...

[flyweightnate]

Yeah, PEM studs. Crossed my mind...

The bottom tube is just hammer, so I might have access. One concern is whether I could still get an open class feedneck in the same spot, or if the nut would be too tall, but I think I have a CCI feedneck and adapter still, which is a bit taller...

This needs a CAD model to check clearances. It very well could work.

[flyweightnate]

https://www.mcmaster.com/product/93580A659

PEM studs. Just need an arbor press to install.

[Siress]

The Gargoyle never had them press-fit... Just loosely held in untill the female threaded part held it in compression. That way it could be easily removed.

[XEMON]

What about freak bore the body and make a freak spacer, slip the freak spacer in the barrel so the the freak insert itself stick out the back and seats where you want?
the only downside is that you have to use freak barrel ...

[flyweightnate]

As crazy as this sounds... boring the body is beyond my abilities, but I think I can do all the other stuff. And I like the idea of using any barrel I want.

[XEMON]

Not crazy at all, the other way would be to put the sizer insert in the body (between the bolt and the barrel) a la ATS ...

[Chaos]

I was just going to suggest this... Use part of the body to retain the insert because of the insert goes far enough back so that it connects with the existing breach hole.... The advantage to this also is it'll give you a little bit of meat to put the threaded insert for where the feed goes

[Spec]

What about freak bore the body and make a freak spacer, slip the freak spacer in the barrel so the the freak insert itself stick out the back and seats where you want?
the only downside is that you have to use freak barrel ...

This was the best idea I've thought of for a Sterling fix. Bore the body 1 inch for freak backs. Trim some freak XL inserts to 6 inches. Run with a regular freak back. Add an extended body spacer so we can mount a vert reg at the same time and we have a kick ass performer.

[XEMON]

I didnt thought about trimming an XL insert down, thats a great idea 👍

[DocsMachine]

Being the board's foremost expert on moving feednecks...



I can tell you how I'd do it- though that would necessarily require machine tools. (What can I say? My guitar only has the one string, I gotta plunk it. )

I'd thread the original hole for something fine, generally either old SP feed neck, or old Angel feed neck. I'd turn a plug to match it, thread it appropriately, and then slather it with red Loctite and screw it tightly into place.

Once the adhesive has cured, I'd bore and ream the bore back to size, and then spot, measure and rebore the new feed port- which, if you're using the Phantom feed, could be straight up/vertical.

The plug will never be invisible, but with care can be filed and smoothed to the body profile, and then when reanodized or Cerakoted, will be almost unnoticeable.

Doc.

[Super Nova]

yay right feed angel

[flyweightnate]

Yep, I remembered a writeup or two on the issue.

I can't "bore" the body - my little 3-in-1 only has a 3-jaw with lots of runout - but I'm curious about threading the plug, now. And yeah, Loctite and Cerakote will be happening.

[Frmrspec]

I'd thread the original hole for something fine, generally either old SP feed neck, or old Angel feed neck. I'd turn a plug to match it, thread it appropriately, and then slather it with red Loctite and screw it tightly into

seems like a ton of work for how simple the body is… if being relegated to having to use machine tools then one could almost as easily just make a new body…

what one user has done is cut off the upper tube completely and use a ccm t2 top tube which opens up a lot of potential for change

[XEMON]

I have a cocker body that gonna get the top half chopped off ... Not sure what I'm gonna do with it yet ...

[Siress]

CCM T2 top tubes growing on trees now? Sounds like an awesome build. Do you have e pictures?

Also, anyone that has made stuff knows that a few operations is not 'almost as easily' as the numerous operations required to build a full body. The full body would be more fulfilling though...

[Frmrspec]

if you want the REEEEEEAAAALLY simple way to do this, buy a sacrificial barrel, have someone cut the end off(threaded portion) then bored, tapped/turned for internal barrel threads (basically a breech extension) screw it onto the body and epoxy/red loctite it on, then drill that part for the phantom stub… don’t even bother patching the existing hole, and have a longer custom bolt made.

that’s essentially how I made my magfed TM15

[DocsMachine]

seems like a ton of work for how simple the body is… if being relegated to having to use machine tools then one could almost as easily just make a new body…

-Heh. That's like saying since a shopping list and a novel both use words, writing a bestseller is as easy as writing that list.

Machining that body from scratch would take six to ten times longer, depending on your skill and available tooling, than just patching the hole.

Doc.

[Siress]

I wonder if it's worth adding a full-length dovetail rail on top (like so many guns from the 80's-00's) to give you the height needed for female threads for the CCI feed... it might disrupt the ball stack so would need to check that first.

It'd have to be an add-on rail, and the threads would likely need to be an insert.

[Grendel]

What about just cutting back the top tube and rethreading for the barrel of choice based on the existing bolt length and feed location. Now this should be done with machine tools but without having the body to make measurements and check clearances.

[flyweightnate]

This was my first choice; the way the old Sterlings are made, there's not enough web bergen the tubes. A typical barrel would have to be cut into the tube where the hammer goes. Not like a Merlin, where they're almost 0.25" between tubes.

[Frmrspec]

I’ve rethreaded a few Sterling bodies for cocker thread and it was dodgy for sure.. maybe A5? 7/8-20 is a super common thread

[flyweightnate]

I'm almost through the woods on this one, just waiting on the reamer to arrive. I'm shocked at how soft the base metal is - lots of deformation when I pressed in a plug with only 0.004" interference. So I might be taking a crack at a new body a bit later... but I think this one will still work as intended.