Neck tension

J E Custom

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Joined
Jul 29, 2004
Messages
10,723
Location
Texas
LOL! 🤣

I thought I was the only one OCD enough to go through this. Well, almost. I don't have the capability to measure seating force.


All of this stuff is not for everyone, But if you want to improve an already good load, a certain amount of OCD may be required. None of the improvements I have found trying to get in to the 1/4 MOA crowd have come easy.

At some point it may not be necessary or needed, But as a reloader there comes a great deal
of satisfaction when you discover that a small change in your procedure made a large change in accuracy.

J E CUSTOM
 

badthirtyone

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Joined
Nov 26, 2007
Messages
439
Location
Denver Colorado
All of this stuff is not for everyone, But if you want to improve an already good load, a certain amount of OCD may be required. None of the improvements I have found trying to get in to the 1/4 MOA crowd have come easy.

At some point it may not be necessary or needed, But as a reloader there comes a great deal
of satisfaction when you discover that a small change in your procedure made a large change in accuracy.

J E CUSTOM
J E Custom,

What mandrels are you using that you are buying by .0005" increments? Most of my searches, and mandrels that I own can only be found 1 or 2 thou under caliber size. I'd be interested to know who makes them as shown in half thou increments.
 

J E Custom

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Joined
Jul 29, 2004
Messages
10,723
Location
Texas
J E Custom,

What mandrels are you using that you are buying by .0005" increments? Most of my searches, and mandrels that I own can only be found 1 or 2 thou under caliber size. I'd be interested to know who makes them as shown in half thou increments.
.001 thousandths. If i need one with less than .001 I just make my own.

J E CUSTOM
 

badthirtyone

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Joined
Nov 26, 2007
Messages
439
Location
Denver Colorado
So, whose mandrels do you prefer, and do you have any thoughts on going with the carbide vs steel/nitride? I have all carbide, but trying to determine if it is worth it. By the looks of your video, it might be worth my while to get a larger set than the standard 1 and 2 thou under caliber size. That's why I was enquiring about what you had referenced.
 

badthirtyone

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Joined
Nov 26, 2007
Messages
439
Location
Denver Colorado
Here is a link to the Mandrels in .0005 increments.
sedancowboy,

Thanks, that was exactly what I was looking for. I poked around on their site earlier, but totally missed these. I found the regular expander and turning mandrels that were 1 and 2 thou under, but could not locate these.
 

AZShooter

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Joined
Dec 12, 2005
Messages
2,718
Location
Tucson Az
Watched the video and another video on the 21st Century sizer mandrels.

Pondering some of the methods employed. Author used a standard FL die to shoulder bump and size neck to a smaller dimension. Then he use the mandrel of his choice to obtain neck tension. He showed that this method yielded very low ES.

In a second related video he mentioned using a bushing die to slightly reduce neck diameter then opening it up with the mandrel.

I see these two methods as having some interesting differences. In my observations most FL dies drastically reduce the OD of the neck because there are many manufacturers making different neck wall thickness brass. The die must reduce the thinnest neck wall enough to allow the sizer ball to open the neck to a useable neck tension. It seems to me that while this would work there is some overworking of the brass. Author said he anneals after every firing so that would certainly remove the hardening aspect of the tighter standard dimension FL die.

Use of a bushing to slightly reduce the OD so a mandrel would achieve the proper neck tension will not work the brass as much. But there is the issue of some of the neck not being sized by the bushing.

Would be interesting to run a comparison of those two setups.

All interesting stuff.

I can envision a custom FL die that has a neck dimension that is not going to over reduce the neck OD but just enough for the use of a mandrel. It would size the entire neck.


Would love to see a comparison of a precision ground FL die with neck dimension made for exact neck tension vs a standard FL die and mandrel.


I have a 30 BR that uses a standard RCBS FL die with neck turned to a dimension so the die is used without a sizer ball. It makes some very straight and consistent neck tension brass.
 

Kmccord

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Joined
Nov 30, 2016
Messages
818
Location
Reilly Springs, TX
I have been struggling to get my group size down on a 6.5 Creedmoor, watching this video had me go and measure my Redding FL sizer ball, it measures a .261 on the calipers, measured the Berger 140 EOL and see them at .263 with calipers, measured my Laupua brass after first firing and FL sizing comes out to .260. I even measured some of the Virgin Laupua neck size and see some at .260 and some at .263 with Calipers. What are you guys doing to shrink your group's on neck tension?
 

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