Machinist help!

[Addicting]

I’m restoring a Remington model 24. It was my Grandfather’s and has been passed down generation to generation.

It needed a new stock and tlc after close to 100 years of use. I’m fitting the new walnut to the action and need to dry fit everything. I had to order a new magazine tube which is identical to the old one. The original was worn out and broke upon removal.

The receiver threads need to be chased as they have two bad spots in the threads. It just wants to cross thread.

The OD of the mag tube thread is .490 and it is 32 threads per inch. I cannot find anything that matches. There is a 1/2 32 available. What do I do? @p_ham

 

[p_ham]

If the minor diameter on the internal is .45-.46 it's 1/2-32 and there are taps available.
Get either a taper or plug style, bottoming will be too hard to start. The damage on the mag tube threads can be fixed with a triangle file.

 

[cahunter805]

Very cool project. Should be no problem to chase those threads.

 

[Addicting]

Very cool project. Should be no problem to chase those threads.

I’m 70% there. It got completely disassembled and went out to precision bluing. Came back looking like new. I have the stock mostly sanded to shape. I had to order a 80% blank. So there was considerable sanding. It’s definitely been a labor of love.

The old stock got cut up and turned into a walnut pen set. At the pace I’m working on it I should be done in 5-10 years. Lol.

 

[Arcola]

Another way to skin that cat would be to remove the damaged threads altogether. Mag tube should be easy to clean up with some patience, but internal threads are tough to repair without the right chaser or tap.

 

[JT88]

Slather it in red loctite, build an adapter to hook it to a 3/4" impact and rattle it on. You know, like they do at jiffy lube

 

[p_ham]

You know you're going to have to put up some photos right?

 

[slatebuilder]

McMaster Carr has 1/2-32 taps if you think that’s what it is.

 

[Addicting]

You know you're going to have to put up some photos right?

I haven’t been taking any. I’m not as good as documenting as you are.

 

[Mallardsx2]

I would take an end mill and remove the damaged part of the threads. Chasing threads could go badly and make things much much worse.

 

[WapitiBob]

Chamfer the first thread out of the action and run a 1/2-32 thru it.
You'll also need the right tap, don't just buy one off the rack at Ace, check the pitch dia. Your tenon is undersize at .490.

UN imperial screw thread calculator

theoreticalmachinist.com

 

[Addicting]

I would take an end mill and remove the damaged part of the threads. Chasing threads could go badly and make things much much worse.

Don’t have that available. I would need to send it off to have it done.

Chamfer the first thread out of the action and run a 1/2-32 thru it.
You'll also need the right tap, don't just buy one off the rack at Ace, check the pitch dia.

That I may be able to do. Here is the tap I ordered.

Amazon.com: 1/2-32 TPI HS SPECIAL THREAD TAP-BOTTOMING : Industrial & Scientific

Buy 1/2-32 TPI HS SPECIAL THREAD TAP-BOTTOMING: Thread Milling Taps - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[WapitiBob]

That's a +.001 pitch. Might be a tad loose when you screw it all together but will probably work. The btm tap is only gonna give you 1-1/2 thread lead, be careful when you start it.

 

[p_ham]

I haven’t been taking any. I’m not as good as documenting as you are.

It's something I have to force myself to do.

 

[p_ham]

Chamfer the first thread out of the action and run a 1/2-32 thru it.
You'll also need the right tap, don't just buy one off the rack at Ace, check the pitch dia. Your tenon is undersize at .490.

UN imperial screw thread calculator

theoreticalmachinist.com

Looking at the thread crests, they're pretty flat, which was pretty common for mass produced threads. The pitch diameter could be spot on but unless measuring across wires then who knows.

I do agree that's not the best tap for the job though.
Look for a taper or plug tap that's 1/2-32H1.

 

[Addicting]

To be honest I am struggling to understand all this talk about pitch. To me a tap is a tap, I ordered that one as it is a bottom out and this hole the threads go all the way to the bottom.

 

[p_ham]

To be honest I am struggling to understand all this talk about pitch. To me a tap is a tap, I ordered that one as it is a bottom out and this hole the threads go all the way to the bottom.

A bottom tap is meant to thread up against the bottom of a hole. It only has 1-2 tapered threads to help with starting.
Taper taps have a long leade for easier starting and less cutting pressure.
Plug taps are between the two.
Pitch diameter is the diameter at halfway up the thread flanks. It's what controls the fit of the threads. Don't worry about it too much in this application, just don't go any larger than H3 on the tap size.

 

[Addicting]

A bottom tap is meant to thread up against the bottom of a hole. It only has 1-2 tapered threads to help with starting.
Taper taps have a long leade for easier starting and less cutting pressure.
Plug taps are between the two.
Pitch diameter is the diameter at halfway up the thread flanks. It's what controls the fit of the threads. Don't worry about it too much in this application, just don't go any larger than H3 on the tap size.

I found a plug one and ordered it. It doesn’t have any details on H1 or H anything. Since they both are Amazon I can just return the one I don’t use. Thanks

 

[WapitiBob]

Use the plug to start then switch to the bottom.
I tried wires about 25 years ago then walked over and grabbed the thread mic.

 

[Addicting]

Plug tap showed up today. It didn’t want to start and when it did man was I scared. It seemed to take a lot and I was worried it was ruining the action.

It turned out good, even with my skill set.