Full length sizing die won't expand case neck?

M

majormarine

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I thought the rod in the rifle full length sizing die flushes the case mount, so that it makes it easy for bullet seating. Unfortunately, this isn't the case, especailly when seating a light bullet which is not boat tail.

I know there is such thing as universal expander die, but can i get away with it?
 
Sizing dies usually include a stem that has an expander "ball" attached to it.

When you raise your case into the die, the ball enters the mouth of the case, then the case is raised up further which compresses the neck.

When you withdraw the case, the ball gets pulled through the mouth, expanding it to accept a bullet.

Check to see if a expaner ball is present

Check that it is the correct size

Chamfer the inside of your case necks. You could just be hanging up on a bit of squared off (and not tapered) inside mouth brass..
 
The case is meant to be resized at the neck or it would not hold the bullet properly.
If you are using cases that have not been chamfered at the mouth ( the inside sharp edge removed ) then trying to get non boat tail bullets is very difficult.
Either get the chamfer tool or use boat tail bullets. You can use a knife to chamfer also.

Colin W
 
The universal expander die is a useful piece of equip. in that it only bells the case mouth to accept cast bullets without otherwise affecting case neck tension.
 
Neck Tension

Too many people do not give out enough information. Posting something like "I have an old gun--What is it worth?" is not very helpful. Also, like computers, garbage in=garbage out. Lots of these guys will help you, but you have to do your part.

Lets have a bit more information on what you have, and what you are doing. From your original post, we can only help you by giving you some general information, but some problems occur more frequently with certain cartridges, dies, etc.

What calibre cartridge are you using? What dies? For example, some 7.62x39 dies come with two expander balls, one for .308 and another for .311 bullets. Using the wrong one could affect neck tension.

Secondly, take a micrometer or vernier calipre and actually measure the expander ball. Then measure your bullets. The bullets should be .001-.002 larger. As posted before---chamfer the brass case mouth.

Third. You say you are using new brass. Are you fully putting it into the die so that it actually sizes down the neck, or are you only putting it in halfway? Reloading dies are made to size the neck down undersize, then when you withdraw the case, the expander ball pushes it out to the correct size for the bullet. You have to put the case fully into the die.
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"...have not chamfered them!..." That'd do it. Chamfering the inside of the case mouth and deburring the outside is essential. You'll have to do it every time you trim too. It doesn't need much of a chamfer though. One turn with the chamfering tool is plenty.
 
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