SIMPLE question on neck tension

[prostreet]

I have read and view videos on bullet neck tension until I was dizzy. ( doesn't take much )

Am I over simplifying this or is this is what you need to know.

I understand that a lot of variables go into this.

Wall thickness, concentricity, straight parallel and all, but

The basic drawing I submitted, YES or NO!

Using .001 inch bullet tension as an example.

Any and all comments would be appreciated.

Thank You

 

[memilanuk]

Where did you come up with .299 for bullet diameter?

 

[Snuby642]

The new prs round?

I measure neck od then seat a round and measure to get neck tension.

Thats all the tools I have available.

Short answer is yes, your drawing depicts .001 tension.

 

[prostreet]

Micrometer.

 

[prostreet]

The new prs round?

I measure neck od then seat a round and measure to get neck tension.

Thats all the tools I have available.

Short answer is yes, your drawing depicts .001 tension.

THANK YOU

 

[Snuby642]

Yes a simple micrometer/ caliper works.

The condition of brass / hardness / annealing etc. Have effects but not essily measured except for range results.

 

[prostreet]

the .30 caliber bullets i have should be .308 they miked at .299 , .009 undersize

 

[Supersubes]

the .30 caliber bullets i have should be .308 they miked at .299 , .009 undersize

For a standard .30 cal, the bore diameter (diameter at the land tops) is .300, and the groove is .308. If you shoot a .299 bullet in a typical 30 cal, it will just skip across the tops of the lands, and impart zero twist into the bullet.

 

[memilanuk]

the .30 caliber bullets i have should be .308 they miked at .299 , .009 undersize

Either you need to get some new bullets, or else your tool and/or measuring technique is seriously flawed.

With very, very, *VERY* few exceptions, modern .30 cal bullets from commercial suppliers like Hornady, Sierra, Berger, Lapua, etc. measure .308", plus or minus (usually plus) a few ten thousandths.

If you're seeing something different, the problem is almost assuredly on your end.

 

[Snuby642]

All my (30 cal) 308 bullets measure. 308.

Re zero your calipers, check to see if on inches, make sure to measure behind the ogive .

Never seen a .299 bullet.

 

[Snuby642]

Don't use them if actually .299 especially if running a can.

Report problem with lott # to mfg.

 

[Snuby642]

I would guess if you resized a piece of brass and put a .299 bullet on it the bullet would free fall inside the case.

Tension on my 308 bolt gun rounds is
.0015 to .0020 and I run .0030 to .0035 in 223 gas guns.

Just for a reference.

 

[prostreet]

Either you need to get some new bullets, or else your tool and/or measuring technique is seriously flawed.

With very, very, *VERY* few exceptions, modern .30 cal bullets from commercial suppliers like Hornady, Sierra, Berger, Lapua, etc. measure .308", plus or minus (usually plus) a few ten thousandths.

If you're seeing something different, the problem is almost assuredly on your end.

Thank you, I will check that out. No names but there good bullets. Hope it is my gauge.

 

[prostreet]

Either you need to get some new bullets, or else your tool and/or measuring technique is seriously flawed.

With very, very, *VERY* few exceptions, modern .30 cal bullets from commercial suppliers like Hornady, Sierra, Berger, Lapua, etc. measure .308", plus or minus (usually plus) a few ten thousandths.

If you're seeing something different, the problem is almost assuredly on your end.

Thank you, I will check that out. No names but there good bullets. Hope it is my gauge.

 

[LawnMM]

You're also measuring wrong on the drawing. Bullet IN the case, measure outside of the neck let's say .320" you want to size the neck with a bushing to .319" of neck tension.

The outside neck diameter will swell when you seat the bullet. The outer neck diameter WITH a bullet seated is what you subtract the .001" from.