Ion / Mini feedneck threads

[JeeperCreeper]

Does anybody know what size drill bit and tap I need to make an original Ion / mini feedneck fit to my Ion XE chamber which has no threads and a smaller hole. I have plenty of meat there to make it work.

[Roger7pball]

13/16"-32 UN

[MrBarraclough]

Here is a helpful reference page for feedneck threads. ZDSPB feedneck specs

[JeeperCreeper]

Awesome thank you both

[JeeperCreeper]

So my drill bit should probably be a 25/32?

[Roger7pball]

So my drill bit should probably be a 25/32?

Googling a tap drill chart gave me the same so should be the right size.

[Jordan]

Watch out for the breech orings, I think they're pretty close on regular Ions so careful where you drill.

[JeeperCreeper]

I should be alright. I have to make the hole about 3/16 larger, so as long as I'm centered with the existing hole I will be alright. I have a drill press for this so that makes it slightly easier to not mess up. From what I can tell the inside of the front half of the chamber should be identical as far as o ring locations as they use the same bolt still. The biggest difference I found is the XE has a slightly larger diameter, probably so you can't use them in old Ion bodies which sucks because I really wanted to put the XE chamber inside of my SITH body. It would fit if I had a lathe to turn 1/16 off the chamber.

[JeeperCreeper]

Also I only can drill down precisely 3/16 of an inch, and no more. I was looking at the stock breach, they left about 1/16 of a lip to stop the threads from going all the way to the bolt. I want to do this myself, but I may go to my local machine shop (I mean like 6 doors up the street) and see what they would charge me for this.

[Jordan]

Also I only can drill down precisely 3/16 of an inch, and no more. I was looking at the stock breach, they left about 1/16 of a lip to stop the threads from going all the way to the bolt. I want to do this myself, but I may go to my local machine shop (I mean like 6 doors up the street) and see what they would charge me for this.

I had the same idea for my own project SP1 body and ran into the same issue. I think realistically the correct tool is some kind of end mill so the bottom of the hole is flat and then a special ground tap to thread all the way down.

I wonder if a press-in stub is a better way to go - if it's cut for Empire-spec feednecks there's still a large number of options.

[JeeperCreeper]

I do believe you are right about the end mill. I found the proper tool for about $150, and I don't have the machine to run it. I did however find a tap for $20 that I might grind to a flat tip if I have to. Then again it's only going to be 1/32 difference, and the tap has a taper, so it might put threads low enough for it to work. Again it's probably worth taking a walk to the machine shop and see what they can do.