.308 neck bushing sizes.... and brands....

anelles

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Minuteman
Sep 10, 2019
67
41
Nashville, TN.
I just ordered my first bushing sizing die, I decided to give those a try after using standard dies for years. Even after reading through a few dozen prior posts on this, I'm a little confused on which bushings I need to pickup. I want to order what I'll actually use, and hopefully avoid ordering some bushings I wont need.

Loading for .308, I'm sitting on a mountain of Federal GMM, LC LR, and IMI Match brass. I went and measured neck wall thickness on a sampling of each.

FGMM came out at .338 loaded across all samples, the LC LR 18/19 came out at .015 wall +/- .001, and the IMI Match came out at .015, +/- .001 as well. If my math is right, this (luckily) gives me a value of .338 for all three brass types.

I'm aiming for .002 of tension, factoring in .001 spring back, it sounds like a .335 bushing would handle any of this brass just fine. Does this track?

Would it be wise to pick up a .334 and .336 as well? Or am I just buying bushings that I likely wont use right now?

Finally, it seems many recommend Short Action Customs bushings over the others. Are these worth the investment over RCBS, Hornady, Redding, etc.? Or should I just use the cash to pickup more of the cheaper bushings?

Thanks in advance.
 
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acudaowner

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Full Member
Minuteman
Dec 26, 2018
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Id skip the neck bushings all together and just use the die body to close the neck so it holds a new bullet . let your expanding mandrels do there job of opening the neck uniformed to what ever you desired neck tension should be .
 
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anelles

Private
Minuteman
Sep 10, 2019
67
41
Nashville, TN.
Id skip the neck bushings all together and just use the die body to close the neck so it holds a new bullet . let your expanding mandrels do there job of opening the neck uniformed to what ever you desired neck tension should be .
This has been on my radar as well, I don't currently have an expanding mandrel, and was thinking about trying the bushing die alone to start.

If I go for an expanding mandrel, I'd want to use a bushing to put in about .004 of tension, then use a mandrel to bring it back out to .002 right? I guess I'd be looking at a .333 bushing and a 21st Century .30cal Black Nitride Turning Arbor to accomplish this.

Mostly thinking out loud here, open to feedback.
 

JS/

Private
Minuteman
Oct 22, 2001
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23
For .308 Win. I normally run fired brass through a .339 bushing and deprime. Then if it's Lapua brass it goes through a .335 or if it's Winchester or similar thin brass it goes through a .334. Redding recommends not sizing more than .005 at a time.
 
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