7mm Practical advice with brass

[Jakeleg]

Hi everyone I'm new here,Ive read a lot on here and finally joined. Lots of good info and hope to be able to contribute in the future. My question is Im in the process of having a 7mm Practical made and was wondering what is your choice of dies or bushings in necking down the 300 win mag to the 7mm,I've read some use regular 7mm neck die and some use 300 win mag bushing die. My question is what do you recommend I,m starting out with new ww 300 win mag brass. I was going to get some dies ordered but didn't want to buy anything I didn't need to.

 

[AZShooter]

Is this a 25 degree or 30 degree shoulder 7mm-300 win mag? Do you know your reamer dimensions?

I figure you have read the author's article? In it he talks about what to use to size the fireformed brass. Copied below:

"Suitable neck dies include the Redding .300 Win Mag neck bushing die fitted with 7mm neck bushings, Forster 7mm Remington Magnum neck dies and the Hornady 7mm "Magnum" neck die. The Forster die has a 25 degree shoulder angle therefore it cannot fully size the neck shoulder junction of the Practical however this is not of great concern. A small portion of the lower neck (junction) can be left unsized without posing any negative effects.

If full length sizing is required, a .300 Win Mag or .338 Win Mag die can be used with the decapping spindle assembly removed. The shoulder dimensions are of no concern here, the die being used to decrease case body diameter."

link to entire article:

7mm Practical


I have found bushing dies sometimes catch on the case mouth. I have considered grinding the opening of the bushing on one side creating a taper to help in necking down. Haven't done it yet.

You can use the a 7 mag seating die to partially reduce the 300's neck diameter before you try any bushing dies as you neck down to the final 7 mm bushing die.

Hopefully others will add more information.

 

[Jakeleg]

Yes I read the article ended up useing a redding 7mm neck die and all was well I thought maybe you might have to work it down in steps with different bushings but it turned out alright thanks