rcbs neck die question

[Gaw1983]

Hello, hoping someone could help me out. I bought a rcbs neck sizing die in 223, and it seems to be giving a lot more neck tension than i am looking for, how do i adjust this? Do i have to buy a different decapping mandrel for it?

[243winxb]

The neck area of the die would need to be honed out, so it does not size the neck as small. The factory will do this for a fee. The expander, what your calling a mandrel, should measure .2225" to .222" If its smaller, ask for a new one. There are also bushing dies available that let you have full control of the amount of neck sizing. Redding makes them, Type-S.

[mehavey]

The expander ball (even in this neck sizer die) should set the internal neck dimensions.
You can get different sizes here...
http://www.forsterproducts.com/index...=22705&count=1

But what makes you believe the current neck tension is too high?

[Gaw1983]

I'm fairly new to reloading, but one thing I've heard a lot is that the neck diameter should be 001 smaller than your loaded round. Mine is 003 smaller, and is the making marks on the bullet when I seat it, no matter good of a champher I put on the case mouth

[mehavey]

Unless you pull the bullet, how do these marks become visible?
(and how are you measuring the inside neck diameter?)

[243winxb]

The marks on the bullet are caused by a seating stem that does not fit the bullet well, the extra pressure needed to seat the bullet does not help. First check neck tension by measuring the sized brass, neck, before seating a bullet. Measure with a micrometer if you have one. Now seat a bullet, how much has the neck expanded on seating? .002" is about right. Call RCBS and tell them what bullet your using. They may send you a new seating stem.

[math teacher]

All you need is a new expander nipple.

[wncchester]

All you need is to radius and smooth the edge of the seater plug.

[Gaw1983]

I'm measuring off the very top of the outside of the case mouth of a sized brass, vs a loaded round. I also tried to neck size some Hornsby brass with it, and the case neck seemed too fat on the outside once the bullet was seated. They were changed on the inside and out too, and would not chamber in my rifle

[wncchester]

"the case neck seemed too fat on the outside once the bullet was seated."

The loaded diameter of a cartridge neck is the combined diameter of the bullet and the thickness of the neck. The bullets are a constant, no die can change the thickness of the case necks; your Hornsby case necks are too thick. Or your chamber is too small.

[243winxb]

If the neck sized ammo will not chamber, you may need to full length resize the brass. The neck diameter of a loaded round should not be larger than .253" See SAAMI drawing here > http://www.saami.org/PubResources/CC...0Remington.pdf Soon or later, even a bolt action will need the brass full length sized. Dont forget to trim the brass. *Lube the inside of the case neck before sizing. .

[Bart B.]

243winxb post heading reads: "Neck size for Bolts" Tell that to folks winning high power match rifle events and setting records doing so and they'll laugh at you. Sierra Bullets' been full length sizing their cases used to test bullets for accuracy since the 1950's. I doubt anyone shoots their bullets more accurate than they do.

[mehavey]

I beleive the first objective for neck/partial-resizing is to preserve case life; accuracy second.

[Bart B.]

Several folks have got several dozen reloads on .308 and .30-06 cases full length sizing them in dies that don't use expander balls. Belted cases can get 20 or so if done properly. Key thing is to not reduce body diameters more than 2 thousandths and set the shoulder back no more than 2 thousandths.

[mrawesome22]

No need for NS dies if you set up your FL die correctly.


Sent from HenseMod6.

[Bart B.]

You'll need a case headspace gauge to measure you cases' head to shoulder datum point (RCBS Precision Mic, or equivalent) to know when the full length sizing die's set correctly in the press. Measure the fired case headspace, then lock the die in the press when it full length sizes the case such to set th3e shoulder back no more than 2 thousandths.

Using Redding's competition shell holders that come in different heights helps keep sized case headspace very uniform.

[snuffy]

What we have here is failure to communicate! My favorite line from cool hand Luke!

Gaw, we need a lot more information. You gave us only enough info to get a lot of guessing about causes of your supposed excessive neck tension.
1. Type of rifle-pistol you're trying to load for. AR platform, bolt action, single shot?
2. What make bullet? Weight, flat base, boat-tail?
3. Where are the "marks" showing up on the bullet?

You say you chamfered the inside edge of the case mouth, what with? The standard 45 degree chamfer tools that everybody offers do not do a good enough job of easing the bullet into the case mouth. Get one of these;

http://www.midwayusa.com/product/342...-very-low-drag

(from the midway description)

The Lyman VLD (Very Low Drag) Chamfer and Deburring Tool quickly and easily bevels and removes burrs from the inside of the case mouth. Standard reamers chamfer with a sharp 45 degree angle which occasionally can damage bullets due to the sharp case mouth. This tool is precision machined and hardened with a 22-degree angle cutter allowing bullets to slide in without deforming bullets or case mouths.

Use of the VLD tool will allow seating bullets with minimal damage to the driving surface. A simple test will confirm this. Seat a bullet after using the standard 45 degree chamfer tool, then pull it. Look at the scraping that took place. Then seat one that had the VLD tool used and pull it. You'll be able to SEE the difference.

Another test is to be stubborn, NOT get the VLD tool. Just seat any bullet in a case chamfered with the standard 45 degree chamfer tool. Take a 10X magnifier, look at the junction of the bullet and case mouth. See the peeled/curled up jacket material? That came off the sides of the bullet.

math teacher All you need is a new expander nipple.

Somebodies got their mind in the wrong place!