300 Wim Mag to 30-338

[Craig H.]

I have 300 Wim Mag cases, and I need to neck down to 30 cal. for my new 30-338. Can I just resize the neck to 30 cal and go ahead and reload, or do I need to also fire form first?

Thanks in advance...Craig

 

[memtb]

Morning Craig


While I can't offer a suggestion, I will say Welcome to the forum from North Central Wyoming! memtb

 

[MagnumManiac]

A 30-338 uses 338WM brass necked down to 30 cal.
You will not be able to use 300WM brass without serious trimming, sizing and neck turning to get brass without correct neck thickness.
Sell the 300WM brass to fund the 338WM brass.
As to fire forming, just neck down the 338WM brass and shoot it, it will fire form from that.

Cheers.

 

[Craig H.]

Ooops...I meant to say that I have 338WM brass, not 300WM. Should I use a reduced load for the fire forming?

Craig

 

[K.E.C. Darkside]

I'm not going to ask Why.

I would probably use 338 bushing dies and order a few bushings to neck it down
Without the expander and use a mandrel die for the neck.
And with any ammo it needs shot 1 or 2 times to be formed to the chamber.
May end up neck turning and trimming.
Hope this helps.

 

[Craig H.]

"I'm not going to ask Why." not sure what you mean??

 

[Justice1327]

"I'm not going to ask Why." not sure what you mean??

Your post is confusing. Recommend edit your post and start over slow down and say exactly what it is You're trying to do.

 

[Mram10us]

I made my 30-338 brass from 7mm mag brass, necked up. Tomato..... um, tomato?

 

[K.E.C. Darkside]

"I'm not going to ask Why." not sure what you mean??

I like building Wildcats myself, so I have built some rifles ( cartridges) that seem odd to others.
A 338Wm is a smaller cartridge than 300Wm.
But someone built a 300Blackout and people like it.
So I'm listening and learning.

 

[K.E.C. Darkside]

I made my 30-338 brass from 7mm mag brass, necked up. Tomato..... um, tomato?

This is the easy button.

 

[Craig H.]

Your post is confusing. Recommend edit your post and start over slow down and say exactly what it is You're trying to do.

Excuse me for making a mistake. Never to return!

 

[K.E.C. Darkside]

Craig H
Were here to help and learn.
Share a little more information about your build so we understand what you need.

 

[MagnumManiac]

Ooops...I meant to say that I have 338WM brass, not 300WM. Should I use a reduced load for the fire forming?

Craig

No.

Cheers.

 

[Mram10us]

Excuse me for making a mistake. Never to return!

Some people word things in a way that are to the point, but not always meant to be rude. He has a good point and might not have ill will