Neck Sizing - Noob Questions

[El Cid 92]

Rifle - AI .308, 20" barrel
Brass - Lapua
Bullet - 155gr Amax, diameter 0.309

After initial firing of new brass, I'm getting ready to Neck Size them using Redding Type S with .336 bushing.

Fired Case Dimensions - OD 0.345, ID 0.314
Neck Sized Case Dimensions - OD 0.335, ID 0.305

1. Use expander ball or not?? After cleaning the expander ball and polishing it, the ball measures 0.308. It seems counter productive to neck size using the 336 bushing .... just to have the expander ball open it back up.

2. Too much or too little neck tension. New loaded Lapua brass with 155gr Amax measure 0.338.

Thank you in advance for help with this.

Andrew

 

[remaction]

Re: Neck Sizing - Noob Questions

My $.02 worth.

Your info:
Loaded round .338 - .309 bullet = .029 total neck thickness.
.336 bushing - .029 for the neck walls = .307 or .002 tension
Fired round o.d. .345 - .314 = .031 total neck thickness.
.336 bushing - .031 = .305 id after sizing or .004 tension

As you are not turning the necks, you will have slight variations in the total neck wall thickness due to mfg tolerances. I would leave the expander ball in, in order to provide a more consistent i.d. to prepare for bullet seating.

I would probably use a .337 bushing though, if all the rounds fell between the diameters you mentioned.

 

[leadbullet]

Re: Neck Sizing - Noob Questions

measure the OD of a loaded rounds and go .002 under size bushing, cannot be any simpler.

 

[El Cid 92]

Re: Neck Sizing - Noob Questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: remaction</div><div class="ubbcode-body">My $.02 worth.

Your info:
Loaded round .338 - .309 bullet = .029 total neck thickness.
.336 bushing - .029 for the neck walls = .307 or .002 tension
Fired round o.d. .345 - .314 = .031 total neck thickness.
.336 bushing - .031 = .305 id after sizing or .004 tension

As you are not turning the necks, you will have slight variations in the total neck wall thickness due to mfg tolerances. I would leave the expander ball in, in order to provide a more consistent i.d. to prepare for bullet seating.

I would probably use a .337 bushing though, if all the rounds fell between the diameters you mentioned.
</div></div>

Thanks for the info/reply.

Looking at it on paper it seems that the 337 bushing may be better. I will try using the expander ball again. Would there be any benefit to decreasing the diameter of the expander ball??

Thanks
Andrew

 

[MitchAlsup]

Re: Neck Sizing - Noob Questions

Use expander ball NOT. That is what neck sizing is all about.

Neck tension depends on the abuse a cartrige must endure between the reloading station and the final firing position.

0.001 bolt gun, no abuse (or almost no abuse) where ammo goes from reload station into a plastic box where it is carefully transported to the range.

0.002 bolt gun; where the ammo must tollerate the abuse of traversing unknown terrain while remaining completely conceiled to achieve final firing position.

0.003 semi-auto actions

 

[remaction]

Re: Neck Sizing - Noob Questions

Use expander ball NOT. That is what neck sizing is all about.

Mitch, I totally agree if the necks are all the exact same thickness. Help me understand the benefit of not using the expander ball to bring the i.d. up .002 to match the thinner necked cases if the necks are of varying thickness.

Perhaps I am missing something, but wouldn't that provide a more consistent bullet grip? My use of neck sizing brass (that has not had the necks turned) is two fold, 1) to better center the cartridge in the chamber as the body has not been resized after being fired, and 2) to minimize overworking the necks by only sizing them as much as needed to accomodate the thinnest necked cases (i.e. the expander ball would not touch the walls on these cases). On the thicker walled necks, the expander ball would pull the necks .001 or .002 wider to provide a more consistent grip from case to case.

Not trying to start anything, just wondering if I am missing something?

 

[YAOG]

Re: Neck Sizing - Noob Questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: El Cid 92</div><div class="ubbcode-body">Rifle - AI .308, 20" barrel
Brass - Lapua
Bullet - 155gr Amax, diameter 0.309

After initial firing of new brass, I'm getting ready to Neck Size them using Redding Type S with .336 bushing.

Fired Case Dimensions - OD 0.345, ID 0.314
Neck Sized Case Dimensions - OD 0.335, ID 0.305

1. Use expander ball or not?? After cleaning the expander ball and polishing it, the ball measures 0.308. It seems counter productive to neck size using the 336 bushing .... just to have the expander ball open it back up.

2. Too much or too little neck tension. New loaded Lapua brass with 155gr Amax measure 0.338.

Thank you in advance for help with this.

Andrew </div></div>


Andrew,

For loaded rounds that will see range use I would recommend 0.001" neck tension and for field use 0.002" tension.

Your fired brass is 0.008" larger than the ideal range use 0.337" neck size. This is 0.003" beyond what will reliably size in one step of neck sizing. If you use a 0.336" bushing you will end up with a neck that is significantly smaller than 0.336". Making a 0.008" jump is too coarse and makes for very unreliable neck sizing. If you use a two step neck sizing process with a first pass with 0.400" and then use 0.337" to finish up with 0.337". You could also try a single step size using a larger bushing probably 0.339" or 0.338" but the results will be inconsistent and get worse as your brass gets work hardened.

Is your Type S die a neck size only die or is it a Type S full length sizer? If this is a Redding neck size only die set Redding includes a body die with the kit. You might find you need to use the body die every other time you shoot a case if you are using higher than factory velocity powder charges or your rounds will not chamber smoothly. For consistency many folks eliminate as many inconsistencies as possible by full length resizing every time they reload a case. I do this too as in practice it does make a difference.

I found with good brass where the case neck thickness varies less than 0.0015"-0.002" you will get better results with no expander ball installed. I also tried using the floating carbide ball from Redding and still had the best concentricity neck sizing without the ball installed.

Before you do anything read German Salazar's many excellent articles on reloading and in particular his piece on 2-step neck sizing. His work is well tested and proven. See <span style="font-style: italic"><span style="font-weight: bold"><span style="color: #000099">The Rifleman's Journal.</span></span></span>

Hope this helps!

 

[El Cid 92]

Re: Neck Sizing - Noob Questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: YAOG</div><div class="ubbcode-body">Your fired brass is 0.008" larger than the ideal range use 0.337" neck size. This is 0.003" beyond what will reliably size in one step of neck sizing. If you use a 0.336" bushing you will end up with a neck that is significantly smaller than 0.336". Making a 0.008" jump is too coarse and makes for very unreliable neck sizing. If you use a two step neck sizing process with a first pass with 0.400" and then use 0.337" to finish up with 0.337". You could also try a single step size using a larger bushing probably 0.339" or 0.338" but the results will be inconsistent and get worse as your brass gets work hardened.

Is your Type S die a neck size only die or is it a Type S full length sizer? If this is a Redding neck size only die set Redding includes a body die with the kit. You might find you need to use the body die every other time you shoot a case if you are using higher than factory velocity powder charges or your rounds will not chamber smoothly. For consistency many folks eliminate as many inconsistencies as possible by full length resizing every time they reload a case. I do this too as in practice it does make a difference.

I found with good brass where the case neck thickness varies less than 0.0015"-0.002" you will get better results with no expander ball installed. I also tried using the floating carbide ball from Redding and still had the best concentricity neck sizing without the ball installed.

Before you do anything read German Salazar's many excellent articles on reloading and in particular his piece on 2-step neck sizing. His work is well tested and proven. See <span style="font-style: italic"><span style="font-weight: bold"><span style="color: #000099">The Rifleman's Journal.</span></span></span>

Hope this helps! </div></div>

Thank you for this info. I have read Salazar's article and have heavily considered using his method. I'm likely going to try the .040 and .337 respectively in the near future.

I am using the Type S Neck Sizing Die and Body Sizing Die every 3rd reload. This seems to keep everything running smoothly.

The amount of practical and tried info from this site is great.

Andrew

 

[MitchAlsup]

Re: Neck Sizing - Noob Questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: remaction</div><div class="ubbcode-body">Mitch, I totally agree if the necks are all the exact same thickness. Help me understand the benefit of not using the expander ball to bring the i.d. up .002 to match the thinner necked cases if the necks are of varying thickness.</div></div>

It is true that the expander ball works the necks from the inside, but they are generally a little tooo small and give a bit more tension than desired. Polishing them does nothing to make them bigger.

One chooses a bushing to get the proper neck tension. While it is true that the bushing works the outside of the neck brass: most of the time, the neck thickness irregularities are small enough not to exceede the 0.003 concentricity tollerance on the neck. Which is the main point, the neckmust be round, have enough tension on the bullet, and be concentric.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Perhaps I am missing something, but wouldn't that provide a more consistent bullet grip? </div></div>

Yes, at the cost of neck concentricity issues. Which one does more damage to accuracy?

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> My use of neck sizing brass (that has not had the necks turned) is two fold, 1) to better center the cartridge in the chamber as the body has not been resized after being fired, and 2) to minimize overworking the necks by only sizing them as much as needed to accomodate the thinnest necked cases (i.e. the expander ball would not touch the walls on these cases). </div></div>

yes, more concentric, more reload cycles.

pquote] On the thicker walled necks, the expander ball would pull the necks .001 or .002 wider to provide a more consistent grip from case to case.[/quote]

And while pulling on the unsupported neck, the necks become nonconcentric.

 

[remaction]

Re: Neck Sizing - Noob Questions

Yes, I agree that pulling the expander up through the neck can, and does, contribute to the necks being nonconcentric (on the outside and in relation to the centerline of the chamber, especially when using standard dies).

However, I also believe that if the neck walls vary in thickness, then they are nonconcentric (on the inside) immediately after the neck sizing whether or not an expander is used, as one side is thicker than the other (that extra brass thickness has to go somewhere). That's where I get hung up and decided that "light" ("light" being defined as expanding the slightly thicker walls but doesn't hit the thinner walled cases) expanding would not hurt. On the flip side, you are right in that even light expanding is "working" the brass and will contribute to shorter brass life.

Either way it's damned if you do and damned if you don't. That's why I usually end up turning the necks enough to clean them up and then go without the expander.

I should be spending more time shooting rather than thinking about these things, and that would help accuracy the most!

 

[El Cid 92]

Re: Neck Sizing - Noob Questions

So I'm guessing there is a "law of diminishing returns"...eventually one is chasing the extra 0.001 of something that is essentially negated by the idiot on the bang switch or the extra gust of mouse fart that is unaccounted for in windage hold??

Andrew

 

[remaction]

Re: Neck Sizing - Noob Questions

10-4