hornady hand neck turner
Anybody use this thing? WHo would like to explain their procedure and experience with outside neck turning. I got myself one and its a new gadget to me, chasing the whole clover leaf group thing.
I dont have the tools to properly measure my neck size in the chamber, and I dont have a hand cut barrel or a blue print of the reamer, so heres how I went about guesstimating. I measured two boxes of once fired brass on the od of the neck. They varied by .ooo5. I took the average and added .oo1 as an estimate of brass shrinkage after firing and cooling, this should be very close to my chamber neck dia. I then took that number, subtracted .308 for the bullet dia. Follow me so far? This gives me the total OD of my necks with zero clearance when loaded. From a bit of research I gathered a total of .003 clearance should be adequate and subtracted that from my total. I then divided by two, to give me the wall thickness I need. Simple right? lol
Ok, so then I realized I have no ball mic or proper means of measuring the wall thinkness of my brass to begin with. Bummer. So Im waiting to turn my brass, after I find a ball mic.
To set up the cutter, I had some brass I ruined the other day and decided what better to practice on. So I turned one after it was full length resized. Heres the trouble. The neck is loose enough on the mandrel that I think I will have pretty inconsistent trimming results. Should I have removed the expander ball from my die before prepping to neck turn? I have already trimmed to length within .0005 to get consistent results as far as how much I touch the shoulder. How do I assure I stay concentric and consistent case to case, especially If Im only cutting high spots where my wall thickness is to thin to bury the cutter.
Here is the math if anybody is interested.
fired case neck Dia. .341 plus .001 for shrinkage = .342 chamber neck size
.342 less .308 bullet Dia. = .034 total Dia.
.034 Dia. less .003 clearance = .031 total Dia.
Divide .o31 by two to get each individual wall thickness = .o155
so I need to turn to .o155 neck wall thickness
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