Loose necks

[1lessdog]

I have a 6 MM AI. I fire formed some brass and just neck sized them to decap. Just about every case the bullet falls into the case. Now I have loaded 1000's of rounds and have never had a problem like this. Am using a Redding neck sizing die and I also have a Redding full length sizing die.

What am I missing??

 

[Mulligan]

I have a 6 MM AI. I fire formed some brass and just neck sized them to decap. Just about every case the bullet falls into the case. Now I have loaded 1000's of rounds and have never had a problem like this. Am using a Redding neck sizing die and I also have a Redding full length sizing die.

What am I missing??

Any chance they are bushing dies?
CW

 

[Richard Coody]

If you were just decapping you may not have ran the case into the die enough to size the neck.

If that isn't it remove the expander/decapping pin assembly and size and see what happens. You might have to sand down the expander ball a bit.

Is this neck turned brass?

Older work hardened brass

Get a bushing die and find out just wbat size bushing you need for proper neck tension

 

[1lessdog]

All new brass, Just fireformed and ran thru a neck sizing die. It is not a bushing die.

I bottomed the case out in the die with shell holder.

Is not neck turned brass.

 

[David Christian]

Have you compared dimensions of the brass before and after sizing with calipers? Too much spring back in the new brass?

 

[mgunderson]

Sounds to me like the bushing is too big, or the wall thickness of the new brass is smaller than expected.

Start measuring old and new or before and after if you have them.

 

[bigstick6017555]

First, you need too know the actual dimension of your chambers neck. Then measure new brass, fired brass, and sized brass necks. With these dimensions it will point you to your problem.

 

[gunsandgunsmithing]

Does your die have an expander ball? If so, remove it. If that fixes the problem, polish the ball down to where it yields the neck tension you want. Or just buy a bushing die and the right bushing. If you still have a loaded round of this brass, that the bullet does not fall into, order a bushing .002-.003 smaller than the neck od of that loaded round.