What neck bushing for 300 WM?

Mayday

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im trying to place my final order for the rest of my reloading supplies for my 300WM. from what i have found it seems that .336 is a popular bushing size for most people. my problem is when i do the math and the measurement on my loaded brass i have .333.
my brass is brand new winchester that i plan on outside neck turning, so i will loose some more brass from that. it just seems like i am going to need a smaller neck bushing than most people use, and i find it a bit wierd as if i am doing something wrong.
at first i was just going to order .334,.335,.336 and use which ever one worked best but after checking maybe smaller sizes are what i need.
specs

winchester brass- outside case size loaded=.333
208 amax bullet-.3065
inside case after being sized=.303
wall thickness .013-.015 average=.014

so do i need to order a .332 bushing? and sizes before and after it?
 

ChadTRG42

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Re: What neck bushing for 300 WM?

If your outside neck diameter on a loaded round is .333, then I'd run a .331 bushing. But, if the wall thickness is .014 (times 2) + .308= .336, I'd run a .333 or .334 bushing size. So, there's a little difference here. If you neck turn, you will have to do the math to know which bushing you will need. Honestly, I'd run the smaller of the bushings, which would be .331 (if your loaded OD is .333). And I wouldn't mess with neck turning the brass. It's a lot of hassle for very little gain. BTW, I run a .336 and/or .334 bushings for Nosler brass.
 

Mayday

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Re: What neck bushing for 300 WM?

Thanks for the advice fellas. I just felt like I was running tighter than most.
 

mdmp5

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  • May 7, 2009
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    Re: What neck bushing for 300 WM?

    For nosler brass, I use a .333 bushing. I also use that bushing for hornady brass