Neck Tension for hunting precision

[bazzturd]

I'm moving away from using a bushing die with an expander ball. Currently, I use a Forster full-length bushing sizing die, but I plan to remove the expander entirely. I already decap on a separate press, and I'm looking at purchasing a 21st Century mandrel die body along with a few mandrels.

My question is regarding neck tension and what most experienced reloaders consider the practical range for precision and hunting applications.

For my hunting load, I was considering using a mandrel that's 0.002" under bullet diameter. The cartridge is a 6.5 Creedmoor (go easy on me) shooting the 127-grain LRX. I use Lapua brass, which tends to have slightly thicker neck walls.

For those of you running a bushing-and-mandrel setup, how much neck tension do you prefer for hunting ammunition? Do any of you go as light as 0.001", or is 0.002"–0.003" generally considered a better balance between precision and bullet retention?

For match ammunition, I was planning to try 0.001" neck tension. I'd be interested to hear what others have found works best and whether you've noticed any meaningful differences in consistency or accuracy across that range.

 

[T_Widdy]

.261 mandrel for everything, it doesn’t matter and you don’t want the bullet falling out or getting pushed in

 

[justin davis]

Just depends I guess. I my 6.5 prc .004” NT shot better (tighter groups) than .001 or .002

 

[Quandary]

I run a mandrel that is .002 under bullet width for every caliber I load regardless of use.

 

[wapitibob]

I use .004

 

[huntnful]

Don’t go off mandrel size necessarily. Measure the OD of the neck before seating a bullet and after seating a bullet. I like .002-.003 of neck growth.

 

[B_Reynolds_AK]

Neck tension? Never heard of her.

 

[huntnful]

Neck tension? Never heard of her.

Ben “sheep don’t know what neck tension is” Reynolds

 

[WeiserBucks]

3-5, can't tell the difference in my shooting unless it's on the far end of loose/tight.

 

[Dark timber]

FWIW, a .262 mandrel will probably end up giving .0025 NT after spring back. It works good for me.

 

[Dmoua]

Two thou for everything.

 

[anonymous22]

First point, in the spirit of education, neck tension technically doesn’t exist. I know, and the rest of us know what you’re talking about but the technical term is interference fit.

Second point, the “practical distances” “experience reloaders” is all relative. That’s somewhere between, 0-1400 yards and internet nonsense to benchrest champion. Just to put the source into context.

As to the question, .003 will probably have some spring back giving you around the .002 interference. There isn’t much reason to go more than that on a bolt gun imo. The goal being uniform grip and thus uniform pressure to move the bullet.

4-5 for me is more for ARs where the load cycle is violent, on top of a factory crimp.

 

[bazzturd]

Neck tension? Never heard of her.

She is this mysterious intra web chick