Seating Depth - Thinking Outside the Box

[AlNyhus]

Your logic is somewhat right but there is also some amount of brass flow with multiple firing/sizing ops that ends up at the neck/shoulder junction, creating a bit of a donut. But yeah, necking up creates a healthy donut due to the brass that becomes the lower portion of the neck came from the shoulder, which is typically thicker. Bottom line, while not often severe, slight donuts can occur without necking up.

Yep. That brass has to go somewhere! -Al

 

[dellet]

Your logic is somewhat right but there is also some amount of brass flow with multiple firing/sizing ops that ends up at the neck/shoulder junction, creating a bit of a donut. But yeah, necking up creates a healthy donut due to the brass that becomes the lower portion of the neck came from the shoulder, which is typically thicker. Bottom line, while not often severe, slight donuts can occur without necking up.

I’m think a lot of people would surprised if the would seat a bullet with enough bearing surface to be below the shoulder, above the mouth, and measure the neck diameter top center and bottom. The amount of taper is sometimes a bit frightening.

It would sell a few neck turning tools I’m sure.

 

[urbanrifleman]

"The only real way to fix the donut is don't be near it"

A famous shooter I know said that.

I think for average folks, who don't want to turn necks and add all sorts of other steps, that is true. In fact, being a long way from the donut fixes a lot of issues, from my experience.

 

[Bc'z]

"The only real way to fix the donut is don't be near it"

A famous shooter I know said that.

I think for average folks, who don't want to turn necks and add all sorts of other steps, that is true. In fact, being a long way from the donut fixes a lot of issues, from my experience.

Agreed but in some instances as I posted above, due to magazine restrictions, case neck length and projectile chosen staying above the junction isn't possible.

 

[urbanrifleman]

Agreed but in some instances as I posted above, due to magazine restrictions, case neck length and projectile chosen staying above the junction isn't possible.

I that case, like back when I shot 243, I only sized half the neck

 

[Bc'z]

I that case, like back when I shot 243, I only sized half the neck

Neck sizer. lol
Absolutely, also the benefit of using bushing dies vs standard FL die.

In my case I only have a set of Hornady FL dies and I'm not particularly enthusiastic about spending $300 for a set of Redding with bushings.
Micrometer seater of course

 

[Doom]

The neck/shoulder junction moves forward when the case is fired. It moves backward when the case is sized. That “accordion”motion causes some buildup between.

I would suggest you learn how the case reforms when fired and resized.

 

[jds holler]

So my buddy and I shot together yesterday, and he had decided to go back to neck sizing "like he used to do" with his 8mm Mag.
I happened to look over, and he was using the 2x4 method of opening his bolt. His neck sized ammo wasn't working in about three different ways, and he finally gave up and decided to pull them down and start over. jd

 

[Clancy]

I would suggest you learn how the case reforms when fired and resized.

Clearly, you’re an idiot.

Forward upon firing. Rearward upon sizing. There’s no arguing that.

Ignorance is bliss though, so enjoy it.