The correct tools?

[Tangent]

How are you "calculating"..............neck wall thickness?
You need to use a tubing/(Ball) micrometer for an accurate measurement of this.
Calipers are not the most accurate tool to use for this as the anvils of the face are flat and not round

Measure the diameter of the bullet, measure the diameter of the neck with the bullet seated, take the difference and divide by two. The best I could do as I don't have a tubing micrometer or one that measured down to 0.0001" yet.

As to some comments about measuring, I used to audit labs and I'm very aware of calibration and issues with taking measurements. You can measure something and the displayed value not be accurate, and the way you measured can also introduce errors. I'm wanting to know if I've got a one, two or three thousandths interference fit so an error of +/- 0.001" wouldn't cut it. Just curious to see what others methods and equipment was.

 

[JFrank]

It would be useful to know how best to measure anything so I can get an accurate idea of how much next tension I'm applying

Don’t over complicate this, using calipers and just below the case mouth, measure the neck OD of a loaded round compared to the neck OD of a sized round and subtract.
.269
- .266 = .003 bullet hold / interference fit ( neck tension )

Theres no need to try and calculate spring back.

 

[AlNyhus]

When I'm measuring brass I have a hard time getting the measurements to make sense. I measure a seated bullet neck width, diameter of the bullet and calculate the neck wall thickness. That seems to come out at the same or larger than the mandrel diameter. However I can feel the mandrel doing its work so obviously my measurements aren't accurate.

What tools are you all using to do this?

For anyone not familiar with measuring to the .0001, this is a great micrometer to get you comfortable doing so. It gives a digital readout w/o going the route of a battery powered unit. I have two of these and use them constantly. They are also less bulky than the larger electronic versions.

https://www.amazon.com/Mitutoyo-Digit-Outside-Micrometer/dp/B00WMLHOZO

Good shootin' -Al

 

[Doghed]

I use K&M mandrels to set neck tension and always buy the corresponding gauge pin which is used on every case as it comes off the press. I cover the primer pocket with a finger and if I get a smooth piston like feel its done. If it feels a little rough or tight I'll run it again.
As Chef Tell used to say...very simple, very easy.

 

[divingin]

I'm wanting to know if I've got a one, two or three thousandths interference fit so an error of +/- 0.001" wouldn't cut it. Just curious to see what others methods and equipment was.

A set of pin gauges will answer that pretty quickly. You can buy an assortment of sizes for not much money.

 

[Webster]

Thanks. I'd rather avoid neck turning as I'm not a BR shooter. It would be useful to know how best to measure anything so I can get an accurate idea of how much next tension I'm applying. However if you want to know how improve your ammunition BR shooters are the people to ask

Just shoot the rifle without measuring anything and see what gives the best groups. Most of us don't have a rifle or shooting skills good enough to see a small change in neck tension. If you cannot consistently shoot round groups around .200-.225" you won't be able to see a difference. There are many other things to improve accuracy. It’s very expensive to try different powders and bullets. You didn’t describe the rifle and what it’s used for. Try some Berger bullets.

 

[farmerjohn]

For anyone not familiar with measuring to the .0001, this is a great micrometer to get you comfortable doing so. It gives a digital readout w/o going the route of a battery powered unit. I have two of these and use them constantly. They are also less bulky than the larger electronic versions.

https://www.amazon.com/Mitutoyo-Digit-Outside-Micrometer/dp/B00WMLHOZO

Good shootin' -Al

Dang Al, wish you hadn't done that! Got one just like that that stays on top of my desk and like you I use it a lot. I just clicked on your link and saw the price on the new ones... thinking of maybe putting it in the safe at night... didn't realize how long I had been using it.... John