Neck sizing question - .223 and .308

[amlevin]

I have just recently started to neck size all my .223 brass used in my .223 Bolt action as well as brass for my .308, without using an expander of any kind. No "ball" on the de-priming rod or using a separate mandrel expander die as I had in the past.

It seems like the necks of he case have a slight taper when I do this. The case mouth seems to be of a smaller ID than the rest of the neck. As I seat the bullets there is a large amount of resistance as the bullet enters the neck but as it moves past the first 50-60 thousandths it is nice and smooth. Naturally I never noticed this when I followed neck sizing with a sinclair mandrel.

My neck tension is .002" and I anneal regularly. Neck thicknesses are uniform within a few tenths. The .223 seating die is a Redding Competition and the .308 is a Forster "Ultra something or other with micrometer"

Any observations, suggestions, ideas, comments?????

 

[waldo1979]

What is your neck thickness? The batches of .223 Lapua I have measure 0.013" fairly uniformly so i don't touch the necks. Some of my lake city brass (09' and 05' head stamps) needed some touching up but I was only able to knock off the high spots otherwise they'd drop sub-0.012".

Maybe you have a donut on the inside of the neck? How many loads/firings does the brass have on it?

 

[artbosco]

What does your mic tell you the amount of taper is in 10,000 thousand from the neck/shoulder junction to the end of the neck?

Do your bullets have pressure rings on them? ???