Need Advice on Using Expander Mandrels

[QuietTexan]

Option 4 (4:03) - He used a -0.003" bushing then a -0.002" mandrel. No joke he's moving to neck too much. Good thing bushings and mandrels come in increments so you don't have to squeeze the **** out of the necks like he did. Could have used a -0.002" bushing and a -.0.001" mandrel to better effect.

I've put my money where my mouth is on this, I'm on the list for an AMP press and I won't comment on what the charts should look like until I can actually do it myself and see.


Also, this, which I agree with and don't need to retype because he said it best. Credit to @Mikecr:

There is importance to pre-expansion that should also be considered.
Downsizing adds energy to brass. The brass will then seek lowest energy balance by springing back counter last action. Most at once, but continuing over time. So if last action is downsizing the brass springs back outward, and will continue to relieve itself over time. So if bullet seating after collet sizing does not upsize necks, then tension will decrease over time. You would need to excessively downsize, so that seating bullets function the same as an expander mandrel to prevent tension loss over time.

Sinclair mandrels

OK, my experience here. Sinclair mandrels used to be more than just one per caliber, at least in 22 for 556 ammo neck tension tickiness (read Zedicker if you want more info there), I don't recall the special order process but it exists and the Zedicker sizes used to be a SO but on the shelf and...

www.longrangehunting.com

 

[Western4444]

Option 4 (4:03) - He used a -0.003" bushing then a -0.002" mandrel. No joke he's moving to neck too much. Good thing bushings and mandrels come in increments so you don't have to squeeze the **** out of the necks like he did. Could have used a -0.002" bushing and a -.0.001" mandrel to better effect.

I've put my money where my mouth is on this, I'm on the list for an AMP press and I won't comment on what the charts should look like until I can actually do it myself and see.


Also, this, which I agree with and don't need to retype because he said it best. Credit to @Mikecr:

Sinclair mandrels

OK, my experience here. Sinclair mandrels used to be more than just one per caliber, at least in 22 for 556 ammo neck tension tickiness (read Zedicker if you want more info there), I don't recall the special order process but it exists and the Zedicker sizes used to be a SO but on the shelf and...

www.longrangehunting.com

Quiet Texan ,,, you are correct. What ever method being used … need to form or compress the neck brass as little as possible. Even if you anneal, Work Hardening the neck too much will shorten the life of the brass. I measure and inspect before and after every piece of brass to see if I have overworked them. I reload about 100 rounds a week, so I feel good about my method and approach. I use to live in Texas now live in Wisconsin, still kept my hat and boots. Great State.

 

[redleg1013]

Just to try something different, I have decided to give this mandrel thing a go. I've always been pleased with the results from using Redding Type S Match full sizing dies with neck bushings and carbide expander buttons, but want to see if removing the expander and using a mandrel instead will have any effect on ES and SD.

I'm looking at the 21st Century die with the window and their caliber specific mandrels. I'm not ready to go all out on the mandrel kits so where should I start? How far do you size down with a bushing and then what size mandrel would you run through to get around .002 neck tension? Say I'm sizing ADG brass for a 7 SS, would a .283 mandrel give me the desired tension with spring back?

Tag

 

[Wedgy]

I get a little less runout when I use the mandrels compared to bushing dies alone but I can't really see the difference on the target of anything under .003" so that's my goal post on runout. Where I do notice the most difference in in seating pressure variances..... much less with the mandrels and a lower ES. Good thread on AS about it and seating with an arbor press;

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[Troutslayer2]

I use graphite lube, the kind that comes in the little plastic case with the brushes sticking up- I think Forster makes it. Run the case neck over that brush before running the mandrel through it. One of the best uses for mandrels is new brass. It's pretty surprising how differently each new piece feels and I do believe I get more uniform neck tension on that first firing because of It.

A concentricity gauge is one of the next things I want to add. I have no idea if the mandrels are doing anything for me in that department.

 

[ntsqd]

Option 4 (4:03) - He used a -0.003" bushing then a -0.002" mandrel. No joke he's moving to neck too much. Good thing bushings and mandrels come in increments so you don't have to squeeze the **** out of the necks like he did. Could have used a -0.002" bushing and a -.0.001" mandrel to better effect.

I've put my money where my mouth is on this, I'm on the list for an AMP press and I won't comment on what the charts should look like until I can actually do it myself and see.


Also, this, which I agree with and don't need to retype because he said it best. Credit to @Mikecr:

Sinclair mandrels

OK, my experience here. Sinclair mandrels used to be more than just one per caliber, at least in 22 for 556 ammo neck tension tickiness (read Zedicker if you want more info there), I don't recall the special order process but it exists and the Zedicker sizes used to be a SO but on the shelf and...

www.longrangehunting.com

Possible that experience has shown that a .002" interference fit* to the bullet works better for that particular chamber-brass-bullet combination? Never mind the elastic to plastic yield transition point of the metal in the case necks says should be the sized down to dimension, just flawed or not, what the guy has observed to work best.

Just to be clear on what you're thinking, it isn't that he's taking the neck .001" smaller than the mandrel size, and then moving it up .001". It is that he's taking the neck .003" smaller than the nominal neck size rather than only .002" under?

*(Note that I am not, and will not call that "neck tension".)

 

[RWE]

Tagging in as well with a question - do you all that live with dry materials tumble to remove the lube after?

 

[TXTrained]

Just to try something different, I have decided to give this mandrel thing a go. I've always been pleased with the results from using Redding Type S Match full sizing dies with neck bushings and carbide expander buttons, but want to see if removing the expander and using a mandrel instead will have any effect on ES and SD.

I'm looking at the 21st Century die with the window and their caliber specific mandrels. I'm not ready to go all out on the mandrel kits so where should I start? How far do you size down with a bushing and then what size mandrel would you run through to get around .002 neck tension? Say I'm sizing ADG brass for a 7 SS, would a .283 mandrel give me the desired tension with spring back?

That's a good question ...that I s for a lo g r ange precision shooter..or a bench rest shooter.
For a Hunter it is a waste of time and money.
You don't have to b e that precise to kill an animal..You're way over thinking this.
Fir people like myself we buy the Mandrel set in half thousandths increments normally.
The 21st Century is what I use.I started out with some cheaper ones by FORSTER. . .Actually I made a mistake and bought a 6.5 mandrel from Sinclair.It was too big.I didn't know any better.
You are doing right by asking people on here THAT really know alit.Much more than I do.Good Luck and MERRY CHRISTMAS

 

[SealT5]

Tagging in as well with a question - do you all that live with dry materials tumble to remove the lube after?

I've personally do not. I expand. Load. And shoot!

 

[dok7mm]

I use a Q-tip inside with Imperial dry, run the mandrel and just tap the neck on a paper towel. The neck residue seems to give better seating consistency.

 

[30BR]

…the most consistent interference fit would come from using a mandrel if you don't neck turn.

I'm pretty anal with neck turned brass on my 6mm, and using a .262 mandrel on my body sized brass (to .0015" shorter headspace than fired) which was then neck sized with a tn bushing, revealed several that felt very tight, some that felt snug, a lot that felt right and some that had no feel at all. None measured any different; at least my tools could not detect it.

 

[Paulstarr]

I found the best route is Redding neck bushings,Wilson chamber seaters and a arbour press, then you can really feel the neck tension and adjust to suit by changing the bushes.I found the best aid to improved ES and SD is annealing after every firing, then there is no spring back, hope it helps.

 

[RWeeks7mm]

For my 7mm RM I use Hornady Custom Dies with a .309 bushing then use a -.002" mandrel (mine is K&M Precision). For the lube I use graphite powder in an old film container with #7 1/2 shot.

 

[SealT5]

MERRY CHRISTMAS!!!!!