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?

 

[Bob3700]

I run very light neck tension. The weight of the loading press handle seats the bullets. My loaded rounds are also .030" into the lands so that is the reason for the soft seating.

Rather than just depending on the sizing bushing to regulate your neck tension, use a mandrel (like a Lyman "M" die) to uniform the inside neck diameters. That way, no mater what sizing bushing you are using, the mandrel make the neck IDs all the same.

The number of times your brass is fired will also dictate neck tension. After 3-5 firings, the brass will spring back more and increase your neck tension.

Bob

 

[SWThomas]

I run very light neck tension. The weight of the loading press handle seats the bullets. My loaded rounds are also .030" into the lands so that is the reason for the soft seating.

Rather than just depending on the sizing bushing to regulate your neck tension, use a mandrel (like a Lyman "M" die) to uniform the inside neck diameters. That way, no mater what sizing bushing you are using, the mandrel make the neck IDs all the same.

The number of times your brass is fired will also dictate neck tension. After 3-5 firings, the brass will spring back more and increase your neck tension.

Bob

Won't the expander ball that comes with the die accomplish the same thing?

 

[spclark]

For my Palma and long-range 6XC rifles I work towards 0.0010" - 0.0015" neck tension, just enough to securely hold the bullets.

With carefully prepped brass (neck turned after first firing, then Redding S die with appropriate bushing to minimally size necks for the first 0.2", then cases get run over a K&M neck turning sizing mandrel - per Bob's suggestion below; otherwise my sized necks appear to have a slight 'hourglass' shape for some reason - before final trimming & chamfering / deburring) the bullet seating feel is incredibly consistent, which seems to pay back nicely with "waterline" elevation accuracy @ 1,000 yards when I do my part.

Annealing every third firing I believe helps greatly too. I anneal new brass before first firing too, just to satisfy myself it hasn't 'work hardened' sitting on some warehouse shelf.

 

[SWThomas]

For my Palma and long-range 6XC rifles I work towards 0.0010" - 0.0015" neck tension, just enough to securely hold the bullets.

With carefully prepped brass (neck turned after first firing, then Redding S die with appropriate bushing to minimally size necks for the first 0.2", then cases get run over a K&M neck turning sizing mandrel - per Bob's suggestion below; otherwise my sized necks appear to have a slight 'hourglass' shape for some reason - before final trimming & chamfering / deburring) the bullet seating feel is incredibly consistent, which seems to pay back nicely with "waterline" elevation accuracy @ 1,000 yards when I do my part.

Annealing every third firing I believe helps greatly too. I anneal new brass before first firing too, just to satisfy myself it hasn't 'work hardened' sitting on some warehouse shelf.

Are you guys using expander dies to contain the mandrels or some other device?

 

[spclark]

Are you guys using expander dies to contain the mandrels or some other device?

https://www.kmshooting.com/catalog/case-neck-expanding-tools/expand-mandrels_for-expand-iron-assembly.html

I tried Sinclair's tools first, then the K&M products and 21st Century's. For the neck-uniforming operation I settled on K&M's mostly because the mandrels they provide are of a diameter that seems to be just right for my needs. I prefer 21st Century's turner tool for its size (easy to hold) and they provide bushings that allow use of other brands of mandrels if you so desire.

 

[artbosco]

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?

Your barrel will tell you what it likes. It's answer is found on the target. Give all those bushing an opportunity to shake hands with the barrel.