.300 Norma neck tension

[Automag]

ive taken measurements and come out with .337 bushing. However, I have been told that neck tension should be around 40psi since this is a magnum. The .337 is not getting me there. I am around the 25-30 psi mark. Am I missing something?

I am depriving with mighty armory, stainless steel pin cleaning, annealing with AMP, resizing with Redding type s bushing until custom Whidden die comes in. Then seating on KM arbor press. Should I go down to the .336 or .335?

Norma brass
Berger 215gr (although I’m likely moving up tot the 230 OTM tactical)

Thanks in advance for any help

 

[LA50SHOOTER]

ive taken measurements and come out with .337 bushing. However, I have been told that neck tension should be around 40psi since this is a magnum. The .337 is not getting me there. I am around the 25-30 psi mark. Am I missing something?

I am depriving with mighty armory, stainless steel pin cleaning, annealing with AMP, resizing with Redding type s bushing until custom Whidden die comes in. Then seating on KM arbor press. Should I go down to the .336 or .335?

Norma brass
Berger 215gr (although I’m likely moving up tot the 230 OTM tactical)

Thanks in advance for any help

If 0.337 gave you 25-30 psi, I'd go to a 0.336 and that should probably get you to the around 40 psi that your wanting. - IF it was me I'd also get a 0.335 just to have it in case & who knows you may need it later on for something. Or you could sell it as part of a "clean-out" sale later on.

 

[Automag]

If 0.337 gave you 25-30 psi, I'd go to a 0.336 and that should probably get you to the around 40 psi that your wanting. - IF it was me I'd also get a 0.335 just to have it in case & who knows you may need it later on for something. Or you could sell it as part of a "clean-out" sale later on.

Well I don’t necessarily “want” 40psi unless that is, in fact, the correct tension I need. I figured 25-30 was correct, but I don’t know. Any suggestions?

 

[LA50SHOOTER]

The Force measurement feature that I am using with my K&M Arbor press measures force via a dial indicator that is graduated in .001 increments, so I have no way to provide an accurate answer as to a conversion factor. - I would try 25-30 in a 5 shot group and then as well us the next smaller bushing (recording the measurement) and try that as a comparison. - My experience with 30 caliber & up is that heavy neck tension in a lot of cases is a good thing. - Also, depending on the actual amount of the neck that you are sizing will play into the equation of what neck tension will produce the best / most consistent accuracy. - I normally do not size the entire neck when I load, usually I'm sizing 50 to 75% of it so the neck tension applied may be heavy but for only 50-75% of the actual neck length. - Testing will provide the answers to your question.

- Ron -

 

[Automag]

Thanks Ron. I’ll try that....

I generally only size .19” down on the neck of the case. I will start out with the 25-30 (.337 bushing) then try the .336 to see which is best.

 

[ClassCat]

Thanks Ron. I’ll try that....

I generally only size .19” down on the neck of the case. I will start out with the 25-30 (.337 bushing) then try the .336 to see which is best.

Check the inside diameter of your neck dies. Stainless can be be off as much as .0015. Invest in a set of carbide, they are made to a Higher level and are dead on in measurement.

 

[Ledd Slinger]

Is this a magazine fed rifle or single shot?

 

[fredo]

Bushing I use is .3-4 thou less than loaded rd. diameter, for my (mag fed) .30-338 Improved. 215Hybrids are AWESOME...

 

[Automag]

Is this a magazine fed rifle or single shot?

Magazine

 

[Ledd Slinger]

Ok. Then you probably want pretty good neck tension so the bullets in the mag don't move position in the neck under recoil. Measure seating depth of the rounds in the magazine then single feed and shoot a couple other rounds. Re-measure seating depth on magazine rounds to make sure the bullets aren't moving in the case neck. You don't want excessively tight neck tension, but you don't want the bullets moving in the case either. Find a good middle ground

 

[Alex Wheeler]

Theres only one way to know for sure...

 

[Drop Port]

What does your loaded cartridge measure?

What does your rifle say? only it can tell you. As long as you ammo is straight don't be afraid of neck tension some like it some don't.