Honing Die Necks

[drbill]

I just turned the top off of a big full length inexpensive die (won't use the expander ball) while waiting for new dies and am trying to decide how to make the neck of the die a little bit bigger. These are the options I can come up with.

1. 200, 320 grit emery paper like above.
2. Mandrel mounted sanding wheel.
3. Hone - like Sonnen machine.
4. Reamer
5. Hone that looks a like bunch of pack goat turds attached to it.

Concerns are making the neck "true" with no run out.

Also Ill be expanding the neck in another step. If there is run out produced when making the die neck bigger could the expanding "correct" some of the "unintended" die run out?

I also know the expanding process can cause some run out of its own but I have had good success with this loading method.


Did you get all that? lol Its like a giant full length custom bushing die with no bushing, the bushing can only get bigger and never be removed. rofl

Any other suggestions and/or experience in this matter?

 

[Bart B]

Concerns are making the neck "true" with no run out.

Also Ill be expanding the neck in another step. If there is run out produced when making the die neck bigger could the expanding "correct" some of the "unintended" die run out?

I've made several full length sizing dies to the "gelded" type; no expander balls needed. After striping the dies of all parts, I chucked 'em in the headstock of a lathe top-in, bottom-out, jaws on the threads, then checked 'em for runout with a dial indicator on the inside about 1/4" up from the bottom. Out of about ten of them, only one needed a thin paper shim under one headstock jaw to get less than .002" runout. I think that's good enough. I chose to chuck the dies in this way so any taper in their necks would be towards the case mouth. I probably could have chucked 'em bottom-in top-out, but thought that would put a reverse taper in the die's neck. Spinning the die keeps a fixed lap/hone well centered just like gun drills are fixed as they're pushed into spinning barrel blanks; they're perfectly centered.

Used 400 grit emery paper wrapped around a 1/4" split wood dowel in the dies with about 200 to 300 rpm's. In and out a couple of times, then clean out the residue, hole mic the diameter. Repeat as often as needed to get the die's neck diameter to what I wanted. The .308 Win. and .30-.338 Win Mag full length dies all had neck diameters of about .327" or something like that. I "emery'd" them out to diameters from .332" to .337" depending on what cases they would be used on.

Tests with all on fired cases showed neck runout on full length sized cases to be .001" maximum. With bullets seated and runout measured 1/10th inch back from tips, pressure ring on a V block and case shoulder in a nylon washer holding the case shoulder at mid point, even long 220-grain ones in the magnum cases had about .0025" maximum runout. I think .003" runout on 30 caliber rounds is plenty good enough; never seen any accuracy improvement with smaller runouts.

 

[Nimrod]

find a machine shop where you live that has a honing machine.
will scost you maybe $10.00

I run a Sunnen hone in a machine shop and I guarantee it would cost a sight more than $10.00 to get one honed there. Minimum shop charge is $65.00, that's also the hourly rate on the manual machines.

I do hone some of my own dies, some I don't bother with. Unless you do it your self it would be more cost effective to buy bushing dies IMHO.

Bob

 

[Nimrod]

I just turned the top off of a big full length inexpensive die (won't use the expander ball) while waiting for new dies and am trying to decide how to make the neck of the die a little bit bigger. These are the options I can come up with.

1. 200, 320 grit emery paper like above.
2. Mandrel mounted sanding wheel.
3. Hone - like Sonnen machine.
4. Reamer
5. Hone that looks a like bunch of pack goat turds attached to it.

Concerns are making the neck "true" with no run out.

Also Ill be expanding the neck in another step. If there is run out produced when making the die neck bigger could the expanding "correct" some of the "unintended" die run out?

I also know the expanding process can cause some run out of its own but I have had good success with this loading method.


Did you get all that? lol Its like a giant full length custom bushing die with no bushing, the bushing can only get bigger and never be removed. rofl

Any other suggestions and/or experience in this matter?

I can tell you from experience that a reamer probably won't give the desired result, I have tried this several times and never could get a good surface finish. Also because of the hardness of the die you will most likely need a solid carbide reamer, the carbide tipped ones never worked for me, even in a CNC lathe. I have never tried the other methods since I have a hone at my disposal.

Bob