Gage pins...

[Papa Charlie]

Nice, thank you for sharing this. Never thought about setting the final neck dimension by expanding the case. Always had a concern that there was a lot of spring back on the case necks. Seems this would greatly reduce that by undersizing then expanding to the final.

 

[Devin Wiggett]

I use the same system David has and I do check for run out and have never had an issue. Typically you are only expanding. O005 on annealed brass so to think that your going to bend the neck at the shoulder is a bit absurd. Furthermore I challenge you guys to do a run out test at distance, because you will find with in reason it has very little effect.
All of us have have been down the road of utmost perfection in our reloading, but you have to test and decide what's really necessary. I know US Shooting team members who dont even clean or uniform primer pockets OMG works for them.

 

[David Christian]

I use the same system David has and I do check for run out and have never had an issue. Typically you are only expanding. O005 on annealed brass so to think that your going to bend the neck at the shoulder is a bit absurd. Furthermore I challenge you guys to do a run out test at distance, because you will find with in reason it has very little effect.
All of us have have been down the road of utmost perfection in our reloading, but you have to test and decide what's really necessary. I know US Shooting team members who dont even clean or uniform primer pockets OMG works for them.

@Devin Wiggett, I learned this technique from the best mentor ever. Thx!

 

[Dusty Stevens]

I wouldnt want to push the donut to the outside if i had one. Theres no way to push it evenly out and its just going to go right back when you size it. I use the porter die with the $3 vermont gage pins when i want to try inbetween bushing sizes but ive never needed to tune that fine really.

 

[riflewoman]

Just wondering...

if these couldn’t be adapted to ride inside a 7/8-14 threaded hole? Pressed on bushing? With a lock collar to “trap” the shank in the press? https://www.mscdirect.com/product/details/88815170

 

[SLuke]

Just wondering...

if these couldn’t be adapted to ride inside a 7/8-14 threaded hole? Pressed on bushing? With a lock collar to “trap” the shank in the press? https://www.mscdirect.com/product/details/88815170

Isn’t that basically what Kenny porter does with his dies? He uses an Er style collet to hold gage pins in his dies.

heres a thread from JoeR describing the die
http://forum.accurateshooter.com/threads/all-things-mandrels.3966618/

 

[riflewoman]

Looks cool! Thanks.

 

[Jay Christopherson]

@David Christian ,

Does this really shear it off (physically remove it) or does it just roll it over and make a burr facing toward the primer pocket.

I tend to use specifically sized end mills that will actually cut them out without any damage to the neck walls.


- pat

you guys and your donut fetishes... ;-)

The donut is only in your head or an improperly (for what we do) designed chamber.

 

[Jdne5b]

Don't forget kids. Sprinkles are for winners. I'm hungry.

 

[pat fulghum]

@Jay Christopherson , You're sounding like my wife... I do need to give up on the donuts...

 

[WIB3]

When the necks start to grow in thickness due to brass flow, get new brass. I use pins to measure the progress but I also change bushings to keep the neck tension the same. It gets to a point where it easier to change out cases.

 

[AccelR8]

I've long held reservations about this notion. The limitation of that, as I see it, is that a donut cannot be pushed completely to the outside (rendering the inside a virtual cylinder) while on the mandrel, at least not with brass walls on the order of .010" thick (and brass not nearly dead soft.) One could verify this by inspecting closely the outside of the neck while on the turning mandrel. The donut will hold a tighter grip on the mandrel while outside turning, and inevitable spring-back will leave a (possibly) reduced inside donut after removing the mandrel. For our purposes one might reduce a donut sufficiently this way, but reaming (in a proper tight-fitting reamer die, or on a machine lathe) is the only practical way I can think of to completely remove a donut. Your idea of shearing it with one stroke of a pin gage is intriguing, but I wonder if a harder (carbide?) pin with a carefully dressed corner wouldn't better meet the requirement.
-

This is precisely what I am finding right now. I am converting 223 brass to 222 (long story). There is a donut. I press the resized/reformed case onto a .224" mandrel for neck turning. After turning on the lathe to .010" neck thickness, pulling the case off the mandrel, and attempting to resize the neck with a Lee collet die (mandrel in it measures .2218") I was getting no sizing down of the neck at all. It came off the turning mandrel measuring .244" and out of the Lee collet die still measuring .244." Perplexing at first. After all of this, I can detect the donut in the cases by using an expanding ball gauge. I didn't bother to try to measure the donut but it can be detected easily. The gauge slides easily in the neck but stops at the donut.

Since my bullet base is up in the neck, away from the donut, I found that by placing a washer over the case when sizing works. I figure without the washer the collet fingers were squeezing the neck onto the mandrel at the donut where the brass was thicker, and the thinner neck portion was not getting squeezed. The washer apparently gets the donut portion down out of the collet fingers.

 

[Straightshooter1]

I figure without the washer the collet fingers were squeezing the neck onto the mandrel at the donut where the brass was thicker, and the thinner neck portion was not getting squeezed. The washer apparently gets the donut portion down out of the collet fingers.

Hmmm??? The pressure of the collet fingers is tremendous and with that kind of pressure, irregularities are squeezed into the relatively soft neck wall. In part, this is one of the reasons the length of the neck grows when being sized??? So, from what I've observed with my brass, any donut that has formed is squeezed away by the collet fingers since the small surface the donut has can't resist that pressure. This is one of the reasons I prefer sizing my necks with a collet die vs. using a bushing die.