My question today is based on my observation (more like a revelation ) concerning neck thickness diminishing as cases get sized, fired and resized. Below is a brief outline of what I have in brass and have done which leads me to the questions; Is this normal and will this change be reduced with my new dies? Is there something I should try to do differently? Or is there a step I should eliminate or add to my process? A few days ago, I purchased a new set of dies to use specifically for my .223 Rem 700 VSSF II with the original barrel with about 950 rounds through. The dies are Redding S type with the Comp Seater. I also bought several bushings based on 3 batches of brass I have; a .250, .248, .246, and a .244. This was my jump off point knowing I could get the in-between sizes or greater/lesser sizes in the future. As for the brass I have: #1 batch is new in the box Hornady unfired- un-turned (100 pc), new brass has necks with consistant thickness/runout between .0145" and .0155". #2 batch is Hornady with 2 firings (100 pc from the same batch as above) and was turned after the first firing. From my notes, after turning, the necks were 0.014". Now after the second firing, they are .0125 to .0135" They are cleaned but otherwise need to be reworked before loading #3 batch is Winchester (100 pc) - turned after 1 firing and now have 6 firings. These necks started at .014 after turning and last night, they range between .011 and .0125. This brass is also cleaned but otherwise un-prepped for loading. Up until last night, all resizing was done with a Hornady full size die set to move the shoulder .0025" This die is also used for my AR15 where I use different brass and brass retired from the 700. None of the brass has been annealed. I'll get into this someday soon I'm sure, just not today. After each FL sizing they were also trimmed and deburred to 1.750". Last night, I set up the new body die on 10 pc of Winchester brass to bump the shoulder exactly .0015". The new neck die was set-up to size 90% of the neck using the .244 bushing and the cases chamber perfectly. Are my observations normal? How far could I let the neck thickness diminish to before they should be tossed in the scrap pail? Thanks in advance for any and all replys.