Redding bushing size for 308?

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adrenaline681

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So for what I've read to determine your bushing size, you need to measure the neck of a loaded round and subtract 0.002".

The neck of my loaded round (Using Winchester brass and A-Max bullet) is 0.331". Minus 0.002" will be 0.329".

After looking at the Redding bushing chart I'm a bit confused because it says that the range for 308" is .335-.343
https://www.redding-reloading.com/online-catalog/58-bushing-range-chart

I've done some reading and a lot of people use bushings around the 0.336" range.
Is it an issue that my bushing will be outside of the range specified by Redding?

Thanks
 
I'm tagging this for interest.

I'm using .336 on Lapua 308 Palma brass. Using a good, K&M ball micrometer, the brass was a fairly consistent .015 thick at the neck right out of the box. Before I fireformed them, I turned them down to a perfect .0145 … in order to achieve .001 neck tension with a .336 bushing.

Now, I have some once fired Winchester around that I may (or may not) reload. Your brass is theoretically .0115 thick and mine (again using a ball micrometer) is showing .012.... I would say your math is spot on with a 0.329 bushing.

Maybe just ignore what Redding is posting on their site, and just go with what mathematics is telling you?
 
The Forster .308 neck sizing bushing bump die comes with three bushings .336″, .334″, .332″

If you knew the neck thickness of your brand of cases and if you plan to neck turn you would have a better ball park idea of diameter.

And if you do not anneal you will have more brass spring back as the brass work hardens.

Note, the Redding bushing FAQ tells you if you do not neck turn and the case neck thickness varies .002 or more to use the the expander that comes with their die.

https://www.redding-reloading.com/tech-line-a-tips-faqs/132-faqs1

Question: Do I need to use the expander button that came with my Type "S" Die?

Answer: It is advisable to use an expander button to maintain consistent neck tension if the case necks have not been turned to a uniform wall thickness. However, the expander button can be replaced with the Decapping Pin Retainer (included with your Type "S" Die) if the user does not wish to use an expander button.

The above methods of determining bushing size require that the cases being sized have a fairly uniform neck wall thickness or have been neck turned. If the neck wall thickness varies more than 0.002", it may be necessary to use a bushing a couple of thousandths smaller than your calculations indicate, and then use a size button in the die to determine the final inside neck diameter.
 
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Munkey1973 said:
I'm tagging this for interest.

I'm using .336 on Lapua 308 Palma brass. Using a good, K&M ball micrometer, the brass was a fairly consistent .015 thick at the neck right out of the box. Before I fireformed them, I turned them down to a perfect .0145 … in order to achieve .001 neck tension with a .336 bushing.

Now, I have some once fired Winchester around that I may (or may not) reload. Your brass is theoretically .0115 thick and mine (again using a ball micrometer) is showing .012.... I would say your math is spot on with a 0.329 bushing.

Maybe just ignore what Redding is posting on their site, and just go with what mathematics is telling you?
Click to expand...

So maybe the Winchester brass is thinner that's why im getting such a lower number. My neck thickness measures (with calipers) about 0.012" if I double that by 2 sides would be 0.024" plus the bullet diameter 0.308" = 0.332"

I think the safest for me will be to get a 0.330" bushing that way I should have between 0.001" and 0.002" neck tension.
 
For the initial cost of the bushings, and it is a one time cost, vs however many different types of brass you may wind up using down the road, get a set of three like Forster provides. Maybe you'll use them all, maybe you won't, but having them when you need them, is far better than waiting for an order for one that you also have to pay freight on. Right now you have a .308win, maybe you'll wind up with a 30-30 and a 30-06 and a 300WM or a Blackout or something, then all you will need is the appropriate die w/o bushings, as you'll already have those, which is a bit cheaper anyway.
 
Why are you going to all this effort and expense for Winchester brass? My opinion of Winchester brass went way downhill recently when some twice fired brass started to develop cracks in the neck. Obviously thin, and brittle brass - these attributes are not desirable for reloading.
BTW - most folks use Norma or Lapua brass for the type of shooting you are trying to do.
 
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