30-06 Bolt Gun: How much neck tension for best accuracy?

[SWThomas]

Hey fellas! I'm gather up some more tools to try out when loading for my 30-06. I just ordered a Redding Type S FL Bushing die and a bunch of bushings to go with it. I got bushings from 0.330 to 0.337 since this will cover the range of brass I have. My loaded rounds measure the following with the following brass:

Lapua: 0.337
Win: 0.333
Fed: 0.335

How much neck tension do you guys try to achieve for best accuracy when loading for a bolt gun? 0.001 or 0.002? I can't imagine you would need any more than that.

What say you?

 

[Sig Marine]

I've been using a .335 bushing with Lapua in a .308 with good results.

 

[SWThomas]

I've been using a .335 bushing with Lapua in a .308 with good results.

Ok I'll bite.... How much neck tension does that give you?

 

[Sig Marine]

If a loaded round is .337 and you size to .335, it equates to .002 or 2 thousandths neck tension

 

[SWThomas]

If a loaded round is .337 and you size to .335, it equates to .002 or 2 thousandths neck tension

I get that. I'm just asking what everyone likes to run since I will be able to dictate it with the bushings.

 

[witchhunter]

Sometimes it depends on your chamber size too. Try em and see which one your rifle likes.

 

[FLIGHT762]

For my bolt guns, I used the -.001" from a loaded round neck as recommended by Redding for the bushing die. Works fine for me, but like you, I have 5 bushings from .329" to .337" which handles handles all of my brass (Winchester, Federal, Speer, L.C., TW, WCC, Hornady, PPU, CBC, IMI, PMC, Remington) types. What you will find is depending on the work hardening of your brass necks, you may need to use more / less bushing sizing to get the desired tension.

 

[Unknown]

If neck tension is only 1-2 thousandths, does this ever cause problems with bullet set back from recoil, or feeding? How much neck tension is required to avoid bullet set back from recoil, or being fed into a chamber? It would seem that semi-auto rifles would either require a crimp (which I really dislike) or more neck tension to prevent setback from being slammed into the chamber.

 

[Greg Langelius *]

Neck tension becomes a crapshoot once one begins to realize that it's actually a moving target. The brass you loaded last cycle is not the same brass your are loading now because sometime during the firing and resizing process that brass became harder.

That's work hardening, and it's a rule, not a guideline.

If the neck has more clearance, there's more stretch, which equates to more hardening. If it doesn't, then neck turning becomes an issue. In either case, annealing becomes a question of some importance.

Greg

 

[SWThomas]

I'll be annealing before every load.

 

[SPAK]

Annealing every firing in my opinion isn't always the best. I've done some testing on my own and found that the second firing after annealing usually produces the best results. That's just what I do. I run .001-002" neck tension on my .30-06 bolt and I've never had a problem with bullets moving under recoil. I've even loaded a few rounds at .001" and dropped them nose down onto a bench several times and the oal to ogive didn't change at all. I've taken the same rounds and pushed the bullet tips into my bench with a good bit of force and they didn't change. .001" neck tension is enough in my opinion, but I shoot for somewhere in between .001-.002". I do anneal every third firing. After about 5-6 firings on .30-06 brass things get inconsistent in the batch as far as neck tension goes.

 

[Jeffvn]

I run 0.002 on my 06.' I use the same on all my bolt guns (6 CM, .308, 7WSM, 7 Dakota, 338LM Improved). I have not had any bullet push-back using 2 Thou.

Jeffvn

 

[SPAK]

The other variable to consider is how thick your necks are. Thicker, longer necks will have more tension than shorter thinner necks.. eg. .001" with Lapua brass necks at .015" thick Vs Winchester .001"with a .013" neck thickness.

either way if you target for about .002" you will be fine.

 

[woojos]

... .002" you will be fine.

This is what I've been using w/ the Lapua brass and the .335 bushing. Either way, once I have a load that is shooting to the limits of my abilities, I stop screwing with it and start loading them up.

 

[SWThomas]

The other variable to consider is how thick your necks are. Thicker, longer necks will have more tension than shorter thinner necks.. eg. .001" with Lapua brass necks at .015" thick Vs Winchester .001"with a .013" neck thickness.

either way if you target for about .002" you will be fine.

I'm aware of the variations in neck thickness with different brands of brass. That's why I decided to go with the bushing die over the standard.

 

[MitchAlsup]

How much neck tension do you guys try to achieve for best accuracy when loading for a bolt gun?

Benchrest with fitted neck: Best accuracy is 0.000 neck tension, just enough to hold the bullet as it is chaimbered. {Do not extract chambered cartrige.}
Benchrest w/o fitted neck: Bet accuracy is 0.0005 neck tension. {Do not extract unfired cartrige is bullet is touching lands.}
Benchrest with extractable cartriage: 0.001 neck tension.
Tactical: 0.001 if you never have to lug ammo across difficult terrain to final firing position, and can slide the bolt home taking your time.
Tactical: 0.002 if you have to lug ammo across difficult terain to final firing position.
SemiAuto: 0.003 to avoid the bullet being pressed into the case when thenose hits the feed ramp, and avoid the bullet jumping forwards to the lands as the bolt rams towards lock.