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

 

[Harvey_NW]

As to the question, .003 will probably have some spring back giving you around the .002 .004 interference.

Spring back give more squeeze.

In regards to precision, my testing showed no difference. I polish my expander balls down to .003" under bullet diameter for around .004" interference, just so they don't get bumped in the mag by recoil or jostling around in a case during season. My primary hunting rifle routinely produces ~.7" 10 shot groups and I had a group of loads I pulled bullets to diagnose an issue, reloaded the seating force was noticeably less than sized brass and the group was still sub 1".

 

[Dave Thomas]

Use a. 261 or. 262 mandrel. If you're groups are where you need them stop there. Most likely you won't see a big difference unless they are way to loose or tight. If you were shooting benchrest then it would be worth testing multiple mandrels.

 

[mtnbound]

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.

I experimented with several bushing sizes for my .223, ranging from .002" to .005" neck tension, but did not observe any consistent improvement in accuracy compared to a standard non-bushing sizing die. As a result, I currently use non-bushing dies for my 22 Creedmoor and 6 Creedmoor as well, and I do not incorporate a mandrel into my loading process.
In my experience, unless a shooter is proficient at building stable shooting positions and highly accurate reading wind conditions particularly in complex or broken terrain any marginal gains that might be achieved through fine-tuning neck tension is insignificant and gets lost in all of the other shooting factors.

 

[bazzturd]

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.

I'm familiar with this but felt that if I said neck interference I would have not elicited as many responses to see what folks thought