Weird neck sizing issue 7mm08

[Lefty Trigger]

Resizing brass for my 7mm08 I have noticed something weird with the necks. They are all resizing to a "funnel" shape? I'm using Hornady brass (3 times fired and I normally anneal at 4th reload) and a Redding S die with a 309 bushing. Right after resizing the bullet pushes in the neck with ease and it get tighter the deeper it goes. Measuring the neck the mouth is indeed larger and it tapers smaller towards the bottom of the neck. Not real sure how that could happen unless it need annealed now because of springback. It does make it super easy to seat the bullets, like handgun rounds....

 

[piie]

Is your bushing set too low (sizing too much of the neck)?

 

[Lefty Trigger]

How could it make the top a larger size than the bottom?

 

[Homerange]

Does more sizing dwell time help ?
With a Redding S die can you flip the bush ? Might the bush have a taper ?

 

[Coyotefurharvester]

What do the necks measure after sizing? Are you using the decapper/expander, if so remove and run a couple.

 

[joshb]

How could it make the top a larger size than the bottom?

You got the Twilight Zone bushing!
Try annealing them and see what happens. All I can think of is spring back.
Are you sure your bushing is still in there? I did that once. Took a bushing out of one die to use in another and forgot to put it back!

 

[JohnKielly]

Are you sure your bushing is still in there? I did that once. Took a bushing out of one die to use in another and forgot to put it back!

Been there using once fired military brass. In that case though, the residue of the neck crimp was enough to hold the cannelured bullets in the case. They shot OK too.

 

[Lefty Trigger]

You got the Twilight Zone bushing!
Try annealing them and see what happens. All I can think of is spring back.
Are you sure your bushing is still in there? I did that once. Took a bushing out of one die to use in another and forgot to put it back!

No doubt,... if there is a twilight zone bushing I can guarantee you that I would get it!
Thats what I'm thinking as well, springback. I think the mouth has less meat there and can expand a little easier than the neck/shoulder junction. I have the last of them loaded now so when they are fired I will anneal the whole batch and see what happens. I have never come across this issue with any other brass even with my 7x57 or my 7mmBR.

 

[mikecr]

How much is the bushing having to downsize the fired necks(diameters)?

 

[Fast14riot]

Normally I would suspect the doughnut in the base of the neck, but thats usually a pretty well defined ring that is smaller diameter, not tapered like you say. Maybe try a collet neck die and see if it still happens?

 

[XTR]

I'm going to bet that it's somehow a function of springback and annealing or absence thereof.

 

[AlNyhus]

What's the inside of the case neck like after firing? -Al

 

[Lefty Trigger]

How much is the bushing having to downsize the fired necks(diameters)?

About 2.5 to 3 thousands. The good news is that annealing the brass solved the issue. Clearly the Hornady brass is not as resistant to work hardening. My normal procedure is to anneal every 4th firing but this Hornady brass is acting up at 3 firings so I guess I anneal every other firing for the Hornady brass until I can get my hands on some Lapua or Norma brass.

 

[std7mag]

Interesting find!
I have some Hornady brass (inexpensive, easy to find) brass for my 250 Savage.
Only have 2 firings on them.
Sizing with RCBS FL die.
I'll have to keep an eye on the necks & see if same issue appears.