So, I've ditched my expander ball

[NCHillbilly]

I've been working primarily on .224 valkyrie loads lately, and realized the expander ball on my decapping stem was not opening up my necks enough to give me the neck tension I was looking for. I am using new Hornady brass, which doesn't show signs of being annealed at the factory. After running through my sizer die (RCBS), my neck i.d. is still .219. I bought an expander mandrel from 21st century which measures .223, but it has only increased my neck I.D. to .220. Would annealing my cases help prevent all or most of the spring-back I'm getting? I would like to get my finished neck I.D. to at least .222. I have access to an annealer, I just didn't expect to need to use it on new brass.

 

[supercorndogs]

All cases are annealed when they are made. The marks are tumbled off. Annealing brass until it has no spring back is way too soft. Annealing is not the solution to your problem. You need a bigger expander if you measurements are correct. How are you measuring the inside neck dimensions? How does it shoot?

 

[Gustav7]

I'd be curious to see an actual inside measurement. Is 3 thou of springback common for you?

I don't think I've ever gotten my brass to springback more than 1-2 thou, mostly 1.

 

[Bradv86]

How are you taking the neck ID measurement?

 

[spife7980]

What are your actual outside measurements?

 

[Haney]

If you are using a pin gage you may need to chamfer the inside edge more, if not fully chamfered you can be getting a false reading .

 

[NCHillbilly]

All cases are annealed when they are made. The marks are tumbled off. Annealing brass until it has no spring back is way too soft. Annealing is not the solution to your problem. You need a bigger expander if you measurements are correct. How are you measuring the inside neck dimensions? How does it shoot?

I am measuring with a digital caliper. As far as shooting, I'm still developing loads, and the rifle is still relatively new, but groups are starting to tighten up.
My initial loads were built with untouched brass, although I checked each piece with a case gauge to assure it would chamber, checked length, and rolled on. I could tell just from the seating effort that neck tension was all over the place, and my s.d.'s bore that out. I feel if I could get the neck tension consistent on all my brass, it would certainly improve my s.d.'s, and probably my groups.

 

[NCHillbilly]

How are you taking the neck ID measurement?

Digital caliper

 

[Bradv86]

If you are using the ID blades on such a small circle you are likely getting incorrect readings. That much spring back seems way out of the ordinary.

What does a sized case neck measure and what does it measure after seating a bullet? Edit: OD measurement

 

[NCHillbilly]

okay gentleman, I want to announce that I'm not a complete idiot, but apparently I've been having a blonde moment. I went to take a series of pics to show you guys, and ended up measuring the OD of an unloaded, resized case, then measured the OD of a loaded round. Turns out I have no issue. I have been measuring the ID all this time, never measuring the OD of an empty and a loaded round. I will say that my seating effort seems quite consistent after running the mandrel through all my cases. Can't wait to shoot 'em now. Hoping this lowers my s.d.'s and tightens my groups. Thanks guys.