Forming 338 Win Mag from 300 Win Mag?

Equalizer · Jan 12, 2020

I have 255 pieces of once fired 300 Win Mag brass (Federal) but don't have a 300 Win Mag. Would this just be running em through a full length sizer die to neck up to .338"? Or will it be Multiple stages? Would I have to turn/ream necks?

bigngreen · Jan 13, 2020

A 338 Win is shorter, you can do it but your looking at pushing the shoulder back, necking up and some trimming for length at a minimum.

jjmp · Jan 13, 2020

Make sure you anneal those cases it will help,your new cases will have less internal volume and hold less powder so work back up to safe pressure ,cheers

AZShooter · Jan 13, 2020

IMO best thing is to recycle it. Federal brass is not that great. Besides when necking down you will be making very thick necks from the body of the brass. Buy some new 338 win mag brass.

Equalizer · Jan 13, 2020

Thanks gentlemen that's the information I was looking for. I'll get 338 brass.

jjmp · Jan 13, 2020

Or trade that brass , not everyone can buy , life's different for us all . Cheers

Equalizer · Jan 13, 2020

Good idea! I'll post it in the classifieds area... I was considering using it just to be resourceful but if someone else could use it in its original form it would be better. Thanks for the perspective everyone

alancthomas · 2024-11-04T08:35:55-0600

Equalizer said:
I have 255 pieces of once fired 300 Win Mag brass (Federal) but don't have a 300 Win Mag. Would this just be running em through a full length sizer die to neck up to .338"? Or will it be Multiple stages? Would I have to turn/ream necks?

Bought a Redding form die for $50 , Annealed them and then I formed them , way easy and then I trimmed them and FLS after that . Very easy process and they gauged perfect . There is only two companys that are selling New 338 win mag brass and MidwayUSA wants $108 for 50ea delivered

Equalizer · 2024-11-04T08:40:01-0600

Nice! Thanks for the info. I found a little bit locally but as you said it's not been very available or affordable when in stock. I will probably go this route myself.

willtim · 2024-11-04T18:29:32-0600

Midway had 338 WM brass.

Forming 338 Win Mag from 300 Win Mag?

Equalizer

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bigngreen

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jjmp

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AZShooter

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Equalizer

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jjmp

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Equalizer

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alancthomas

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Equalizer

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willtim

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