stuppied question neck turning

[glider]

Started using century 21 lath to turn necks , neck wall thickness is very uniform using a ball mic to measure ,
Question turning is to uniform neck wall thickness and indirectly effect concentricity ?

 

[jimcasey01]

If your neck wall thickness is consistent, then skip the turning unless it is needed to chamber the round. If neck wall thickness varies, you can just skim the neck to get an approximately 50-75% cleanup if you feel it is necessary. Turning is not always necessary. Turn a few cases and test them against cases that are not turned. That will tell you whether you need to turn the necks. For some chambers the necks have to be turned to be able to chamber the round. My PPC has a .262 chamber, which requires turning the necks down to .0086 using a bullet at .2433.

 

[glider]

If your neck wall thickness is consistent, then skip the turning unless it is needed to chamber the round. If neck wall thickness varies, you can just skim the neck to get an approximately 50-75% cleanup if you feel it is necessary. Turning is not always necessary. Turn a few cases and test them against cases that are not turned. That will tell you whether you need to turn the necks. For some chambers the necks have to be turned to be able to chamber the round. My PPC has a .262 chamber, which requires turning the necks down to .0086 using a bullet at .2433.

Thanks for explaining , I understand about chambering and when turning is necessary , what Im trying to ask is there any relationship or need to make concentricity better by turning ?

 

[jimcasey01]

I believe that your neck will be concentric on the outside after being fired, assuming your chamber is. If the neck thickness is consistent, then the inside of the neck will match. Insert a bullet and seat it, and any concentricity error in the bullet will be transferred to the neck, with adequate neck tension. Bullets are generally pretty concentric. After that it will depend on your dies, and how you have them set up in your press. The reloading process will typically make your ammunition less than perfectly concentric, to varying degrees. This can come about from the sizing process, bullet seating, or rough handling.

 

[glider]

I believe that your neck will be concentric on the outside after being fired, assuming your chamber is. If the neck thickness is consistent, then the inside of the neck will match. Insert a bullet and seat it, and any concentricity error in the bullet will be transferred to the neck, with adequate neck tension. Bullets are generally pretty concentric. After that it will depend on your dies, and how you have them set up in your press. The reloading process will typically make your ammunition less than perfectly concentric, to varying degrees. This can come about from the sizing process, bullet seating, or rough handling.

After checking press ,dies for adjustments, annealing cases ,lube etc.
Using Redding type S dies .0005 to .0015 run out is acceptable? with proper handeling ?

 

['Freak]

If the OD of the neck is perfectly concentric relative to the case body but the neck wall is .002” thicker on one side than at a point180° opposite it, then the bullet will end up being seated .001” off center because the thicker neck wall will shove the bullet laterally towards the side having the thinner neck wall.

 

[glider]

If the OD of the neck is perfectly concentric relative to the case body but the neck wall is .002” thicker on one side than at a point180° opposite it, then the bullet will end up being seated .001” off center because the thicker neck wall will shove the bullet laterally towards the side having the thinner neck wall.

Thanks Freak your right , looks like neck turning is best ,
With century 21 lath its easy and consistant to get neck thickness uniform .

 

[jimcasey01]

After checking press ,dies for adjustments, annealing cases ,lube etc.
Using Redding type S dies .0005 to .0015 run out is acceptable? with proper handeling ?

Glider, If your loaded ammunition run out, measured on the bullet, is in the range you stated, then you are good to go. Correction, you are doing exceptional! I doubt that you will consistently better the .0005-.0015 run out reading. To achieve zero run out on a regular basis is near or is impossible to achieve with the tools at hand. I personally have never obtained it.

 

[Shynloco]

After checking press ,dies for adjustments, annealing cases ,lube etc.
Using Redding type S dies .0005 to .0015 run out is acceptable? with proper handeling ?

Gilder,
We should all be so lucky! Don't fix it cause it AIN"T BROKE! Anything at .002 or less is good to go.

Alex

 

[glider]

Gilder,
We should all be so lucky! Don't fix it cause it AIN"T BROKE! Anything at .002 or less is good to go.

Alex

wow i was going crazy tryin to have runout more like .0005 /.001after reading how these bench guys are making almost perfecr brass

 

[glider]

wow i was going crazy tryin to have runout more like .0005 /.001after reading how these bench guys are making almost perfecr brass

 

[glider]

forgot to add thank you guys for comments . by the way im using ball micrometer and 60* anvil micrometer along with century 21 conentricity gauge for measurements, all .0005 tolerances .

 

[Dusty Stevens]

If youre only gonna measure to .0005 why use a mic? You need to be holding and measuring to .0001 or you need new turning/measuring tools. Theres no tolerance on turned brass if you care to even turn em in the first place

 

[mikecr]

Are you measuring total runout off the bullets, or the loaded necks?
Are you expanding (pre-seating) necks? With what?
Have these necks been post turn fire formed?

 

[glider]

If youre only gonna measure to .0005 why use a mic? You need to be holding and measuring to .0001 or you need new turning/measuring tools. Theres no tolerance on turned brass if you care to even turn em in the first place

was pointing out tolerance of concentricity gauge , yeah mic is .0001

 

[glider]

Are you measuring total runout off the bullets, or the loaded necks?
Are you expanding (pre-seating) necks? With what?
Have these necks been post turn fire formed?

Post turn fire formed , is something I need to learn about if you care to explain.
Expanding with century 21 expanding die in order to rotate on cutting mandrel this step is where I see run out on brass neck increase

 

[Dusty Stevens]

Running an expander in makes it real hard to keep concentricity down. Let your neck turner float and dont worry about that concentricity- itll go away when you fireform it.