Neck Turning - again!

D

Dave P

New member
So you found a lopsided/lumpy neck, and you turned it down. Now you think you have the best cases on the range. But ...

A lopsided neck can often mean that the entire case is lopsided: a thick area of neck can mean thick area of body.

So what i do (one of the first steps) when I want the best cases that I can make, is roll each case across a flat surface. I use a ceramic floor tile. If it rolls smoothly, it is good, and might not even need neck turning. (check the neck with a ball micrometer)

If I hear and see lopsided motion, the case is not the best, and goes in the plinker pile.

You will be amazed at how many cases are lopsided. But also, many of us won't see any difference on the target, whether the cases are perfect or not.
 
So you found a lopsided/lumpy neck, and you turned it down. Now you think you have the best cases on the range. But ...

A lopsided neck can often mean that the entire case is lopsided: a thick area of neck can mean thick area of body.
Click to expand...
But, the reason for turning a neck with more brass on one side than the other is to make the case hold the bullet more concentric with the bore. The rest of the case (in my opinion) is not going to effect the bullet's alignment.
 
I have some chambers with tight neck and factory neck just won`t fit.
Click to expand...

Strange, strange indeed! Either the ammo maker or the gun maker is not following SAMMI specs. A VERY rare condition.

Jim
 
>>I have some chambers with tight neck and factory neck just won`t fit.
>Strange, strange indeed! Either the ammo maker or the gun maker is not following SAMMI specs. A VERY rare condition.

And dangerous. So many claim that THEIR guns have tight chambers.
thick walls on the case body don't matter, as long as the neck is concentric with the chamber. Those thick walls are interior to the case anyway. Having a neck that is thick on one side will put the bullet off center.
However, let's get serious--this is ONLY a concern for those shooting 0.5" MOA or simply having fun. Otherwise, it won't make a difference--your hunting load aren't going to know to go from 1.5-2.5MOA to 0.5MOA due to concentricity.
 
Well it seams that Dave P found a way to determine case heavy (thick) side. That could be reason to check case volume with water. I believe a small plate of glass would give a flatter surface than a tile.
 
"The rest of the case (in my opinion) is not going to effect the bullet's alignment."

But if the "banana case" does not expand equally in all directions at the same time when the powder is burning, it may tend to kick the bullet base off to the side.

I like to eliminate/minimize issues like this, so that I know I am shooting the best ammo I can make. One less thing to worry about. One more item to eliminate from the question of: why is that a 9 and not an X??
 
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