RCBS Uniflow drop tube thread size?

Can anyone tell me what the thread size and pitch is for the Uniflow screw in drop tube? I am thinking about making something with my minimal tools, but i need this tidbit of info.

Thanks Matt

I believe what you're looking for is 9/16-18

Update: I just verified this, it is 9/16 -18

Thanks... Thinking about making a Lyman 55 custom extension/drop tube holder. Would all be drill press work, I do not have access to a lathe.

Okay?
The Lyman is held in with a thumb screw, I think, and the RCBS, which you asked about is threaded. I have made some replacements for the green plastic RCBS, but you are doing what again??

If you need something turned/threaded maybe you can get some help if more info was added.

I made a drop tube for my Uniflow measure out of aluminum. I had issues with the supplied tube, bridging stick powders when charging my .458 cases. This one has a big hole made for the powder, and is dedicated for 45 caliber cases. No issues since.

I want to basically convert a Lyman 55 to mount like the Uniflow. So, an extended length of 7/8x14 outside threaded. Turned down on the end to slip into the 55 and internally threaded on the other end for the RCBS drop tube. I load in loading blocks and under the 55 there is not enough room to pass a loading block from side to side and end to end. I mount my Uniflow on the RCBS stand with the included steel bar to extend the Uniflow away from the stand. This allows me to rotate away from the press to the measure and dump a tray and then rotate back and load them. I can reduce the shank of the bolt with files in the drill press so it will fit the 55.

I can get a grade 5 bolt to work with or threaded rod. The hard part will be getting the hole thru the center of the bolt. Threading the ID for the drop tube may be tough, I do have taps and dies to work with. The internal thru hole can be tapered to need with a rod and good sand paper.

please look for my PM

I think you are overthinking this... a shelf on the back of your loading bench will provide a solid mount for you Lyman 55 with room to maneuver a shell tray underneath. Any kind of drop tube arrangement you devise will still leave you limited by the size and shape of the holder you make for it.

Froggie

What Froggie says, I am confused about what you are trying to do. Near as I can tell you want to use RCBS drop tubes in a 55??

Yes Pressman, and the 7/8x14 part needs to be longer. That will allow the drop tube end to be lower. I will take pics this weekend and I hope they will explain my idea better.

I realize this is an old thread, but I'm looking to verify the thread size of the RCBS Quick Change Drop Tube Adapter. I believe it's 5/8" x 18tpi. I want to drill and tap the discharge hole of my Ohaus Duo powder measure, and thread in the RCBS Quick Change Drop Tube Adapter, then use the RCBS funnel quick change funnels with the o-rings. Any help would be appreciated!
Attachment 279667

UPDATE: I changed the estimate thread size...I believe it's 5/8", NOT 7/8" x 18 TPI