Question on NOE expander plugs

[woodmann]

I need to order one or two 30 cal NOE expander plugs. I don't understand the sizing. The 308 shows a size of .304" x .308" and 309 shows a size of .305" x .309". I need it for 300 Blackout. I size to .309, and then powdercoat for a finish of about .311. I'm thinking I'd like to have a 308 or 309 neck I.D. giving me two or three thousandths of neck tension. The boolits are cast from COWW and air cooled. No gas checks. Rifle is a single shot Handi.


What the heck are the two different sizes shown for the expanders?


Any obvious flaws or pitfalls in my plan?

Thanks

[JonB_in_Glencoe]

I'd recommend The NOE 312RC Cast bullet expander plug .308" x .312"

http://noebulletmolds.com/NV/product_info.php?cPath=88&products_id=1511 (http://noebulletmolds.com/NV/product_info.php?cPath=88&products_id=1511)

.308 is the smallest part of the expander and it expands the entire Neck area.

.312 is the next sized area, the expands approximately (depended on how you set it up)the top 0.050" to make the best possible alignment of Boolit and case neck, the easiest, it duplicates the Lyman "M" die.

There is even a larger area for flaring the case mouth, if necessary.

[woodmann]

Thanks JonB, That's exactly the info I was looking for.

[gloob]

If you want a 308-9 neck ID, the expander needs to be around 310+. 308/312 is a step in the right direction, anyway. With a 312 flare, the case might still shave a 311 plain base bullet, even with a chamfer.

For an off the shelf product, that is probably the best you are going to get. Good choice.