setting neck tension with mandrels??

[Eric Leonard]

I could see it being more uniform than with bushings but it would take an extra step,,,anybody tested to see if it is actually worth the extra step,,,and another thought,,if it is worth the trouble couldnt Redding or somebody make sizing buttons for the decap stem in different sizes like maybe ,,.2400 .2405 .2410 .2415 etc etc so you could use a bushing to size down a couple thousandths smaller and then use the size button that gives you the amount of neck tension you need,,,it seems if you had any variation in neck wall thickness you would get more uniform tension sizing the necks from the inside,,

the tapered button to neck 220 brass up to 6mm measures .242 so it might work but would be nice to have several different sizes to try,,

I did a search and found this had been discussed but nothing new,,wonder if a person couldnt turn a .257 button down to where they needed it to work,,

 

[Dos XX]

http://www.whiddengunworks.com/product/expander-ball-kits-and-sets/

 

[Eric Leonard]

http://www.whiddengunworks.com/product/expander-ball-kits-and-sets/

thanx ,,yeah thats what I was thinking about,,will they fit Redding and Harrells decap stems or do you have to buy the whole decap stem from Whidden,,

thanx for link

 

[Boatschool02]

I'm not an accomplished benchrest shooter, but I have seen my seating force consistency and velocity spreads improve with the addition of the mandrel step. For right now, I use either the Titanium Nitride turning (-.0015) or expanding (-.0007) mandrels from 21st center that I already have on hand. There is enough spring back from whatever bushing size you choose to achieve anywhere from 0.001 to 0.0025 neck tension.
I discussed the sizing button theory with John Whidden before buying my first set of dies and now agree that for all but perfectly turned necks, an interior step "should" improve seating contact and/or consistency. He went out of his way to emphasize that he can't ever remember a time when his necks wore out before the primer pockets. (Admittedly running at tip of the spear velocities)
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I like the idea of pairing chamber specific non-bushing full length resize dies with custom half thou mandrels.
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Last year there was a group buy on custom made mandrels in 6 and 7mm from JGS.
Even though they sold out, the idea didn't catch on.

 

[BenPerfected]

I could see it being more uniform than with bushings but it would take an extra step,,,anybody tested to see if it is actually worth the extra step,,,and another thought,,if it is worth the trouble couldnt Redding or somebody make sizing buttons for the decap stem in different sizes like maybe ,,.2400 .2405 .2410 .2415 etc etc so you could use a bushing to size down a couple thousandths smaller and then use the size button that gives you the amount of neck tension you need,,,it seems if you had any variation in neck wall thickness you would get more uniform tension sizing the necks from the inside,,

the tapered button to neck 220 brass up to 6mm measures .242 so it might work but would be nice to have several different sizes to try,,

I did a search and found this had been discussed but nothing new,,wonder if a person couldnt turn a .257 button down to where they needed it to work,,

Using expander mandrels in .0005 increments has totally changed my reloading procedures. The K&M expander mandrels and force gauge have moved the consistency in my neck tension to a new level. IMO, the expander mandrel is the most important tool on the bench. My expander mandrel is set up in a separate press next to my Coax and is the final step prior to powder.
Ben

 

[Mikemontminy]

Using expander mandrels in .0005 increments has totally changed my reloading procedures. The K&M expander mandrels and force gauge have moved the consistency in my neck tension to a new level. IMO, the expander mandrel is the most important tool on the bench. My expander mandrel is set up in a separate press next to my Coax and is the final step prior to powder.
Ben

I also use the K&M mandrels which I turn down myself. I run very little neck tension. The inside neck measurement can be verified with a drill guage which you can buy on eBay for about $3.00 shipped. They come in half thousand increments. With the drill guage you can feel when a donut is forming on the inside of the neck. If the mandrel doesn’t remove this I run the K&M carbide cutting pilot inside the neck with a drill to remove it. After doing this the seating force will be very consistent.

 

[UltraBR30]

I also use the K&M mandrels which I turn down myself. I run very little neck tension. The inside neck measurement can be verified with a drill guage which you can buy on eBay for about $3.00 shipped. They come in half thousand increments. With the drill guage you can feel when a donut is forming on the inside of the neck. If the mandrel doesn’t remove this I run the K&M carbide cutting pilot inside the neck with a drill to remove it. After doing this the seating force will be very consistent.

Thinking you may mean pin gauges. Drill gauges are a series of holes in a plate, are they not?
Phil

 

[RussellJ]

http://forum.accurateshooter.com/threads/the-ultimate-solution-to-neck-tension.3909740/

Here Is Your Solution. I Just Ordered The Collet Holder.

 

[Intheshop]

I will no doubt,continue to make different sizes/styles of expander buttons...... and also continue to make custom mandrels.Just like other things "I" do that may or not work for other guys,BUT......

If starting fresh again would go with the Joe R way of "colleting" ,over the counter gage pins.Mainly cause they're already hardened and laziness.

For testing said;If everything else has been worked out on a specific load in one of my better shooting rigs,the mandrels show a slight edge,for the better on ES.Trying to keep it as level a field as possible.Runout being better is a decent bet,but don't take it too far.Once you've established good run out processes.

 

[Just Dave]

After having my full length die converted to a bushing die for my 50Bmg, I will likely have all others done the same way.. I turned down the expander ball small enough to just act as a guide. I can control how much I push the shoulder, and the neck bushings size all but a small portion of the neck, leaving the bottom portion close to the chambers fired dimension, helping center the case. Now these cases have been neck turned, so wall thickness is same, .

 

[davecb]

Would using the mandrel after resizing not cause potential run out problems? I know when I resized using my whidden die, I had to remove the expander because it was causing run out issues. Would think the mandrel would do the same.

Dave

 

[Mikemontminy]

Would using the mandrel after resizing not cause potential run out problems? I know when I resized using my whidden die, I had to remove the expander because it was causing run out issues. Would think the mandrel would do the same.

Dave

I haven’t seen any difference in runout.

 

[ClassCat]

P M sent

 

[BenPerfected]

I haven’t seen any difference in runout.

My results have been the opposite. After using a full length non-bushing sizing die I follow with the KM expander mandrel, my RO has never been better. KM offers standard mandrels in .0005 increments. After washing, the brass is full length sized with a liberal amount of spray lube. Finish forming the neck using the expander mandrel in a separate fixed press. My RO is never more than .002 with most .000-.001.

 

[ireload2]

I have the tapered mandrel from a roller burnishing tool that I use to expand case necks. The small end of the taper is about .240 and the big end is .264 dia. Because it is about 2" long it expands case necks evenly to any size needed depending on depth inserted into the neck. The long taper left inside the case necks seems to be of little to no consequence.
Even if you don't like the concept of a continuously tapered mandrel you need a long taper to any expander lead in to avoid having the neck expand off center.

 

[Sheldon N]

My runout went way down when I switched from expander button to a separate expander mandrel. I have a sinclair carbide turning mandrel (-0.002) and am also getting a 21st Century titanium coated Expander mandrel (-0.001) to have different neck tensions to choose from. It's not an extra step in my worflow since everything is run through a progressive and gets done all at once (deprime, size, expand).

 

[Mulligan]

http://forum.accurateshooter.com/threads/seeking-a-good-source-for-expanding-mandrels.3926813/

Lots of related info here.
A wealth of knowledge on the subject.
CW