hey guys, I want to start turning my necks for my .30-06.
I have a ball mic and a forster outside hand neck turner coming in the mail.
question is how much do I cut without getting to thin? I'm using winchester brass and using calipers (i know not that accurate) I get measurements from .0115 to .015 in thickness variation. I was thinking of turning to uniform the brass to .012. Would that be too thin??? Using a Lee collet die to size the necks..
Sounds like you're committed. You must have already considered what you want..
You want uniform necks with not alot more than 2thou of sizing needed. So what do your fired necks measure fresh out of the chamber? You'll want your loaded necks to measure ~1thou less after turning.
So if your chamber neck is .334" you'll be good with LOADED necks measuring .308 +24(.012x2)=.332", leaving FIRED brass measuring .333(after springback), and 2thou sizing to get .331, providing ~1thou tension(after springback using a .3300 -.3305 bushing).
Or take your [(chamber neck - .308 - .002) /2] for a thickness starting point.
Wait for your ball mic. Your brass may not be as bad as your calipers are measuring. If in fact you do have necks from .0115" to .015" then you have a problem. But if you want to use it anyway then you should turn it to .013" or so. The rule is not to turn thinner than .010" but that is minimum thin. I have 3 rifles with tight necks and turn to .012", .013" and .013".
If you don't have a tight neck then just pick a happy medium that gets the most of your brass as close to the same dimensions as possible. With the Lee Collet then you will push the variances to the outside and it won't effect your bullet runout as much. But the thick/thin variance will make a difference in bullet release so pick a medium.
If you only have a few that are thinner than .013" and the majority are .013" to .015" then turn to the lowest denominator. You can also sort them if you have 50% or so that are consistant then use those for your prime brass and shooting.
If you can read this, thank a teacher.......if you are reading this in English, thank a soldier.
I"m getting some really good groups but getting some brass that are flyers. Last group I shot at 200 yards measured .583" outside to outside 3 shots, the next two were flyers. Took the same 5 brass reloaded them and marked them and the 3 good shot brass did the same at 200yards and the other 2 still flyers almost in the same spots....I've started pulling the brass that have flyers have noticed my groups improving, but unfortunately it's a lot of brass...I'm hoping that neck turning will help to uniform my brass a little bit more....
I assume this 30-06 has a factory barrel, not a custom barrel with tight neck dimensions. In a factory cartridge, there is normally .005 - .006 clearance on a loaded round. You do not need to turn necks. If you want to uniform the necks, you can lightly turn them by skimming just slightly (you will be able to see barber pole turns on the necks).
Since you are getting flyers, I suggest you check the concentricity of the loaded rounds. This can cause flyers, especially if you are using a sizer die with an expander ball inside.
Actually, it's a custom build with a mcgowen heavy barrel with a tight chamber. I don't know the exact neck diameter though. I just want to uniform my necks so they have consistent neck tension from round to round. I've noticed a handfull of brass in my loads that I can visually see different thickness around the case mouth.
you are correct, I'm trying to reduce my runout. Don't have the concentricity guage yet. Trying to get the tools to make straight brass first.
I don't use an expander ball. I size using a redding body die and the lee collet die for the neck.
Going to trim with a wilson trimmer, deburr with sinclair tool.
I was contemplating weighing brass, but it seems as though it's really the volume that I'm concerned about.
Just trying to minimize the variables. I know what the potential is .25moa or better, just want to get rid of the wacky fliers that seem to follow the brass. (i.e. flyers out of one brass remain flyers reloaded subsequently)
how far down do I turn? Just above the line of where the shoulder meets the neck? or do I cut into that line?