284 jazz?

[Ballisticbreath]

Hey guys,

I'm looking at building another 7mm. I'm interested in the 284 jazz pushing berger's 195. Any experience with this round would be greatly appreciated.

 

[TH]

I don't shoot a 284 jazz but I shoot a 7/300norma improved. Which is basically the same thing. I have a 28 inch barrel with the brake it finishes 30.5. Recoil is mild. I haven shot any of the 195s even though I have some. The case for the amount of powder it holds is too big. If I would do this project again I would simply neck down a 300 Norma case to 7mm. No need to improve will not effect velocity. I'm shooting a 180 Berger 3428 fps using H1000. Hope this helps

 

[Ballisticbreath]

Thanks TH,
wow thats flat getting with it! How many grains of h1000 with your gun respectively. I suppose thats not close to filling that case up?

 

[TH]

I'm shooting 84.5 H-1000 that's my accuracy load. Have shot over 3500

 

[Ballisticbreath]

7-300 norma mag is what i was initially thinking. A full length sizing 300 norma mag die and bushing type neck sizing die to step it down 7mm should be all a guy needs to form brass right?

 

[TH]

I would use some case lube also. Plus this saves you the expense of having custom dies made.

 

[Ballisticbreath]

Thanks again TH
That looks like a good way go. i'm gonna check to see what kind of reamer i can find.

 

[Wachsmann]

Is the 300 Norma and the 338 Norma built on the same case. To get the 300 do you just neck down the 338 Norma.

 

[Ballisticbreath]

You can buy 300 norma mag brass, 338 norma mag is the same thing i believe just sized for .338

 

[Edd]

It is the same basic brass but there are some small differences in body length and shoulder diameter. A 30-338 Norma Mag would not be exactly the same as a 300 Norma Mag.

 

[Ballisticbreath]

Thanks for the ifo Edd,
Does anyone know where i can find a 7mm-300 norma mag reamer?

 

[Wachsmann]

I know it great to have something special and something that no one else has but with my 300 RUM already hard to find brass or find retumbo if I was going to build a custom 7mm cal/chamber I would go with the 7mm/300win or just go with a 28 nosler. I have seen more 300 win mag brass than any of the RUM's or the 28 noslers. Or just step up to a 338 Lapua improved. I always see lapua brass around. But this is just my thoughts. I do like the 7mm a lot.