M die repair

[Jeff Michel]

I had to do a repair on an M die so I could finish loading a bunch of .32 Longs, I took a couple of pictures that may inspire some of the newer lathe owners to get a sense of some of the things that can be repaired/replaced/improved in your reloading room or your shooting bench.

Whoever it was at Lyman that thought that making the adjustment stem in an M die out of aluminum was an improvement ought to have his head looked at..... The threads that retained the sizing/flair button tore out of my stem and rendered it useless. Time fire up the lathe! After rummaging in my scrap box, I fished out a piece of 303 stainless steel that would serve admirably for a new stem.

270424.

After turning to size, I squared my tool post using a 1,2,3 block for the threading operation.

270425

Now we thread, 5/8x18 TPI

270426

Used my M die body for a thread gauge

270427

The finished product, about an hour total time including a couple cups of coffee. Was going to knurl the top of the stem a la factory but I ran short of time, I had made dinner date with my favorite girl.

270428

We just ordered dinner:mrgreen:

270429

Good luck with all your projects and post the pictures.

[uscra112]

Doing it the hard way. McMaster-Carr has high strength threaded rod from which I've made numerous custom mandrels. Both for M-Dies and 310 dies. Nice steel - machines beautifully.

[Petrol & Powder]

Nice work either way.

[Jeff Michel]

Doing it the hard way. McMaster-Carr has high strength threaded rod from which I've made numerous custom mandrels. Both for M-Dies and 310 dies. Nice steel - machines beautifully.

Excellent idea, proof there's more than one way to skin a cat. Thanks for sharing.

[MrWolf]

Excellent idea, proof there's more than one way to skin a cat. Thanks for sharing.

Huh, looked like a squirrel to me:kidding:

[ndnchf]

Nice work.

[deltaenterprizes]

I have never seen anybody square a tool post before threading.
I use a fishtail because when the threading bit is ground it may off from square.
That is how we were taught in school.

[sparky45]

I'm going to use that squaring off procedure when I need to cut off a piece of steel. I hate parting off but this might help eliminate at least one of the variables.

[dtknowles]

Speaking of more than one way to skin the cat. Why couldn't you just cut off the adjustment stem and drill and tap a new hole for the expander. I have a few M dies with aluminum adjustment stems and never had one pull out. Did you let it get loose with only a few threads holding. That said, I just bought a new M die and it has a steel adjustment stem.

Tim

[Jeff Michel]

Tim,
Correct, the expander unscrewed itself and pulled the majority of the threads out, it left about two near the top. Thought about shortening and retapping, but would of lost around .375 from the stem and I didn't verify, but I think that I would of lost depth adjustment of the stem.

[redneck1]

I have never seen anybody square a tool post before threading.
I use a fishtail because when the threading bit is ground it may off from square.
That is how we were taught in school.

Notice he used a carbide insert and not a hand ground piece of HSS
I square up the same way as both you guys .
123 block for an insert and a birds mouth for a hand ground HSS tool

[ndnchf]

Could you have repaired the thread with a helicoil?

[Jeff Michel]

Sure, but cost becomes a consideration. McMaster-Carr has the insert tools for about 90.00. A new M die from Midway is 25.00. Whereas I spent........what? 25K for a building full of machine tools, so I can make a couple dollar item??? Probably why I like bullet casting, I'm saving a ton of money there as well :mrgreen:

[dtknowles]

Most of my M dies could benefit from shortening the adjustment stem. The stems are barely screwed into the die when adjusted for my cartridges.

Tim

[uscra112]

Sure, but cost becomes a consideration. McMaster-Carr has the insert tools for about 90.00. A new M die from Midway is 25.00. Whereas I spent........what? 25K for a building full of machine tools, so I can make a couple dollar item??? Probably why I like bullet casting, I'm saving a ton of money there as well :mrgreen:

Drill & tap the stem 1/4-28. Install a short length of matching screw, using strong grade of locktite. Cut off and face off, then drill/tap for the standard Lyman mandrels. Done. And you'll never pull the thread out again.

Almost off topic - these new Lee "universal expander" dies, (which btw do no expanding; they only flare the case mouth) are amenable to using true expander mandrels that simply drop in. No threads. I'm still using my M dies for cases I tooled them up for, but anything new I'm using the Lee with my homemade mandrels.