Second time I have ran into this problem and do not know what causes it or how to correct it. I have been reloading .243 Winchester. I started off with new brass...full length resized before firing, trimmed to correct length etc., all is well. Loaded it up fired all is well,,,renecked...checked length..ok all is well reloaded..now on about the fourth loading I get zero resistance on the upstroke of the expander while renecking and have little or no neck tension. I ran into this before with some Winchester 308 brass? Am I doing something wrong..missing something..setting something up wrong?

Did you neck turn your brass? If you have a mic check a fired brass at the neck and after resizing check it again and see what the difference between the expanded fired case and one resized. The put a bullet in the brass and check the size of the neck then. You may find that you won't need the expander plug at all. Good Luck

I have not neck turned any of the brass and it is sporadic. It is not the whole bunch maybe 10%.

Sniper - Who�s the manufacturer of brass? Have you trimmed more than once? Have you annealed the cases? As Reload suggested mic the neck, check thickness and post what you find. Sounds like thinning of the neck or a work hardened neck.

You may be experiencing "spring back" where the work-hardened neck is squuezed down by the die, but springs back open due to being hard. After 3-5 firings I always anneal the brass.

Try annealing a few of the offending cases, then resize them again.

Don

Don I believe you are onto it. Any advice on annealing? Never done it before.