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21st century Black nitride expanding mandrel

Ajwilly96

Gold $$ Contributor
I can’t seem to find any information online is it worth buying the black nitride expanders over the steel?

Also for selecting size, figuring there’s about .0005 of spring back for 6mm. The basic mandrel would leave me with .2422 then with spring back for a finished neck of about .2427 so .0003 of neck tension?

Vs the custom one at .2415, spring back at .242 leaving me with .001 neck tension. I might be over thinking all this
 
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Youre dealing in ten thousandths, we cant even reliably measure that. Call pete at 21st century and he will help you get what you need. Your springback will vary each time you fire them and will even vary piece to piece. Get the bushing neck die they make and get a few bushings starting at .001 under your loaded round dia and make it simple. You need a bit more tension, drop down .001. Its easy as that
 
Youre dealing in ten thousandths, we cant even reliably measure that. Call pete at 21st century and he will help you get what you need. Your springback will vary each time you fire them and will even vary piece to piece. Get the bushing neck die they make and get a few bushings starting at .001 under your loaded round dia and make it simple. You need a bit more tension, drop down .001. Its easy as that
Do you happen to have any experience with the black nitride versus the steel?
 
I can’t seem to find any information online is it worth buying the black nitride expanders over the steel?
First, so you understand their black nitride mandrels are specifically made for expanding and neck turning case necks. The mandrels they sell for setting your neck after sizing for neck tension are only offered in steel. Of course you can use the neck turning expander and turning mandrels to increase your neck OD for any intended purpose. But you sacrifice the size diameters available in their caliber specific expander mandrels.

I've done a lot of case neck turning using their steel mandrels for expanding and turning case necks. Never have seen any benefit from going to either the TiN, or the black nitride mandrels. No issues with heat build up or wear. I've got several TiN mandrels and a few black nitride that came with neck turning lathes I purchased. Some folks clearly feel they are worth the extra cost for the potential benefit they provide.
 
Just get the black nitride turning arbor to expand your necks, it’s sized 2 thou below bullet diameter. if you are worried about not enough neck tension with the standard black nitride mandrel (1 thou below bullet diameter) this will solve your problem.

i sold all my bare mandrels to get the black nitride (i just didn’t see a benefit to needing such fine tuning increments in neck tension at this time). most of my guns seem to shoot fine with the 1 thou below mandrels anyways.
 
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First, so you understand their black nitride mandrels are specifically made for expanding and neck turning case necks. The mandrels they sell for setting your neck after sizing for neck tension are only offered in steel. Of course you can use the neck turning expander and turning mandrels to increase your neck OD for any intended purpose. But you sacrifice the size diameters available in their caliber specific expander mandrels.

I've done a lot of case neck turning using their steel mandrels for expanding and turning case necks. Never have seen any benefit from going to either the TiN, or the black nitride mandrels. No issues with heat build up or wear. I've got several TiN mandrels and a few black nitride that came with neck turning lathes I purchased. Some folks clearly feel they are worth the extra cost for the potential benefit they provide.
I am definitely getting lost in the sauce looking at all this stuff haha. So I would want the caliber specific expander?
 
I am definitely getting lost in the sauce looking at all this stuff haha. So I would want the caliber specific expander?
he is just saying keep in mind with the black nitride mandrels you are stuck with either 1 thou below or 2 thou below.

they only offer the 0.0005” incremental mandrels im bare steel only.
 
Are you wanting mandrels for neck turning or neck tension adjustment? .001 under bullet diameter is for neck turning to set ID, .002 under bullet is for the turning arbor for proper clearance while turning.

Frank
 
I have made an effort to keep it simple. I have a Sinclair turning mandrel for each caliber bullet I shoot. New brass- mandrel. Brass needs trimming size/mandrel. Fired brass, size/mandrel load.
Yesterday I had some fired 204r brass to load for coyote. Decided to see(feel) the difference between shot a couple times brass and new brass with both bushing(neck sizing die) and the mandrel. Since I had Hornady brass in both stages, that's what I experimented with. Used an igaging 0.0005 digital caliper for measurements.
What I saw/felt. New brass was more consistent, measurement wise, after both mandrel and bushing stages +,- a graduation and bullet seating was smoother/less effort on the RCBS rc handle. Didn't seem like a 0.003 under bushing or the 0.002 under mandrel made any difference seating effort. Did notice cbto seating lengths were closer(40 gr BIB bullets).
Seating effort and cbto was different with the fired brass regardless if brass was final sized with bushing or mandrel. And outside neck measurements varied more. I will anneal some of this brass before reloading it again and see if that makes any difference feel or measurement wise. This ammo is for a thermal optic equipped rifle, so no paper targets will be shot. But I don't think any coyote will live to complain.
 
Anything I already had that was titanium nitride, I’ll keep, but I like the black for stuff I use a lot. Anything but bare steel is a big upgrade.
 

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