308 neck sizing

[Tom Thomson]

I think that my RCBS neck size die (#15530) is working the brass too much. The dia goes from .344 as fired to .329 as sized then to .339 with a bullet seated. I'd like to bore/hone about .006 out of the ring but it's hard to get at. Has anyone pressed the sizing ring out of the tool? It appears to be up against a shoulder with no room for a punch. As I am loading single shot, I don't need much neck tension.
tommyt

 

[fguffey]

The neck sizing die does not have an insert or bushing.

The dia goes from .344 as fired to .329 as sized then to .339 with a bullet seated.

The die has a primer punch/neck sizing assemble, are you suing the neck sizing plug with the die?

F. Guffey

 

[Tom Thomson]

fguffey
yeah it clearly does have a bushing. I'm not sure what your second sentence means, but if you are refering to the i.d. size plug, I'm not using it.
tommyt

 

[jo191145]

Well if you got the 15530 number correct its not a bushing die. There is no removable parts beyond the expander ball primer punch you removed. It is not designed to be used without those parts.
You are correct it over works your brass. Put it together and use it as intended until,you buy a bushing die. Redding S series FL sizer would be my recommendation.

 

[vtmarmot]

To second Tom's post, I believe this die is designed to be used with the I.D. sizer plug. Otherwise, unless you are neck-turning your brass, you are at the mercy of the vagaries and variations of neck thickness. If your loaded neck O.D. is .339 and the bullet is .308, then your necks are .0155 thick, which is quite a bit. If they are sizing down to .329 O.D. you are running .010 neck tension, which is a lot. The I.D. sizing plug might lessen this to .002 or .003. Working the brass is the least of your worries. With this much tension, your seater may even deform the bullet a bit.

If you want to properly control neck tension and only work the brass minimally, get a Redding Type-S bushing-type full length die. Whether you turn necks or not, set it up for .002 or .003 tension. It does not use a button. Even better, turn your necks to .009 or .010 thickness and use an appropriate bushing to get that .002 tension. You can sell your current die on eBay and recoup some investment. If you're worried about neck tension, it's time to take this step. Otherwise, use the button, stop worrying about working the brass, and be happy.

If you want a complete understanding of these things, read Tony Boyer's "Book of Rifle Accuracy".

 

[vtmarmot]

I meant jo191145's post.