Neck sizing bushing size for 270 win

[The Oregonian]

New to reloading here...got my equipment and just digging in for the first time. I have an off the shelf A-bolt stainless stalker in 270 win.

I have a 150 or so Nosler once fired cases (from factory ammo) and also bought 50 new brass so I can measure and compare if needed.

I have deprimed, cleaned, uniformed primer pocket and deburred flash holes. Next step, I believe, is neck sizing (not going to FL size right now as headspace seems right on....also not going to turn necks as I need to get the basics first).

On the Nosler reloading data they show a loaded cartridge having a neck diameter of .308, which allows for .0155 neck thickness.

Measuring loaded factory Nosler ammo has diameter or .305 which would allow for neck thickness of .014...Most of my cases have a neck thickness of .014 +/- a thou (both once fired and new a Nosler brass).

I haven't ordered neck sizing bushings for my Redding comp dies yet and trying to decide what sizes to get.

If I go off the Nosler site data I would order .307 and maybe just get .305 and .306 to have in case they are needed. If I go off of loaded Nosler factory ammo I would get .304 and a couple slightly smaller.

I assume I would go with .304, .303, and maybe .302 as opposed to those which would match up with the Nosler book at .308 diameter....is that correct?

One qdd'l question...after neck sizing, is it trim to length, chamfer / deburr inside and out and then I am finished with case prep, or do I need to run the cases thru an expander (I have a Sinclair expander die with a mandrel that came with my neck tuning kit)? Seems most have recommended an expanded after neck sizing with bushings but want to make sure of right steps.

Thx in advance....

 

[MagnumManiac]

To determine the bushing size you need to measure 10 cases and take the average, I always round down, so if the average is .3055", I take .305" to be the reading. Now you need to determine how much neck tension you want, .001", .002", .003" or whatever takes your fancy. Myself, I prefer to run .0015"-.002" in my target/long range rigs and .002"-.0025" for my hunting rifles.
In your example of .305", I would go with a .303" size bushing and see how it goes, then get .001" larger and smaller if you want to experiment.
There really is no need to trim after every sizing, only trim when the cases exceed the max length. The only time you NEED to trim all the time is when crimping bullets, you won't be doing this, so don't bother.
Cheers.
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