Neck sizing only - inconsistant neck tension

[Bbear]

Loading for my 243 using 90 gr AB's and a Lee collet neck sizing die loading on an RCBS Rockchucker press - about 1 in 10 cases I get NO neck tension. The other 9 come through just fine. Accuracy remains solid out to 500 yards.
Question is, what am I doing wrong?

 

[MudRunner2005]

Sounds like some of your brass has lost its elasticity. Might be time to anneal your cases, or buy some new brass.

 

[rcoody]

Sounds like some of your brass has lost its elasticity. Might be time to anneal your cases, or buy some new brass.

good thought

are you sure you have the die set up right. you must put the same amount of force on the ram each time. The only way I have found to do it consistently is to set the die up where it cams over. then you have a consistent stopping point. I believe the directions tell you not to do that but it works for me.

 

[LoneTraveler]

If your brass is a mixed lot that you have gotten from unknown source. Some of the necks may have been turned and there is just not enough brass in the neck to fill the die and pull the metal in till the bullet will fit. Mike the neck thickness will find this problem. Good Luck

 

[Mikecr]

Sounds like some of your brass has lost its elasticity. Might be time to anneal your cases, or buy some new brass.

The only way to lose elasticity IS to anneal. Process annealing reduces elasticity, full annealing kills it.

I wonder if the offending neck is of the same thickness.