Peterson Brass Belted Mag Basic Unprimed Box of 50

[Mike Matteson]

Why not use Peterson 300WM Long to set for 7stw? The case is longer to the shoulder than normal 300wm cases. you woud have to size the neck down to 7mm, then fire-form them.

 

[Calvin45]

Why not use Peterson 300WM Long to set for 7stw? The case is longer to the shoulder than normal 300wm cases. you woud have to size the neck down to 7mm, then fire-form them.

Would you not still run out of brass length?

 

[Mike Matteson]

Would you not still run out of brass length?

Possible. I looked a little closer. 7STW is a very long case. The only thing I see that is the same length is 7mmALT mag in case length. Not for sure if that would work. Lot larger at the shoulder in ID. Over all case are the same. I'll look at it in moring.

 

[kfreeze]

Check out accurate shooter and search case forming dies. There is a place listed there to get die sets for moving case shoulders and necking down. There have been a few made through the years. I think rcbs even made them. Maybe call them.

 

[Mike Matteson]

Would you not still run out of brass length?

2nd reply Go to Peterson Brass Belted Mag Basic Unprimed Bos of 50.


Started Mar 3, 2022 by BgHunter338. There is straight belted mag case made by Peterson Brass in belted Mag. Total unformed brass except for the belted or base end. There some reading to do. It will get you into step by step and what is needed to do to size the case into something you can use.
It's titled: Peterson Brass Belted Mag Basic Unprimed Box of 50. Total length is 2.890" which is longer than the 7mmSTW.
I look at this last year when Peterson came out with them, and got I think was 150 cases. Started to work on how to form the brass.
Long story short. People here have come up with a fairly easy way to form the brass. There it a few steps to achieve the formed case, buts that life.
Gran & Son would have the brass. Whether they are in stock presently I don't know. I kind of felt that Peterson may have stop making they. Most people gave up in trying to form the cases.
So take a look for that post.

 

[victor3ranger]

No idea on any of your questions but that's awesome!

Now we gonna have people running .475 capsticks at ungodly PSI with this tougher brass and suffering retinal detachment left and right! . Always been intrigued by that wildcat…

lol
This does really have my attention if someone knows how to make these into 7RM or 300 win mag

 

[Mike Matteson]

In the past years I have changed 30/06, 270 7mm brass to 26/06 brass. Also changed 300wm brass to 308NM brass. 280AI to 6mm/280AI brass. That took me 4 steps in reducing the 280AI neck to 6mm. I used Redding type S bushing dies to achieve the neck size of the 280AI case .284 or 7mm to .243 or 6mm.
You need to read this entire blog from front to back. The info is there. What the problems were or are. From what I have read here in this blog. The 416 Rem Mag die was or is the starting step to achieve the sizing of the straight wall case to whatever case you want that is belted mag. Then different dies steps were used to change the case into what that person wants. It can't be done in one sizing other than 416 Rem Mag brass.
Look back through this blog to see what others have done to size down the cases.

 

[Bghunter338]

Hey guys, ok out of the 10 prices of brass that Peterson gave me I was able to accomplish 5 fully formed pieces of beautiful brass. Yes there's a lot of steps and it's hard work to do. But the thing is it is possible to have high quality brass for the great 7 stw. Recently I got an epiphany and started thinking again. . I was able to aquire some 6.5-300 wby brass by Peterson. This was quite easier to form from. All I did was run it one pass in the mandrel die and load it with maltomeal and blue dot to fire form. The cool thing to do this you don't need a rifle primer so your not wasting primers. I have a bunch of large pistol primers that I don't use for anything so now they have a use lol. Below is a picture of finished 6.5-300 wby converted to 7 stw.

Next picture shows the basic belted mag next to the wby.

The basic is the one on the left.
Thanks for following along. The reason I started this project was to help guys get brass for their 7 stw. One of the greatest cartridges ever made in my opinion and it's sad the the big companies let it die off. Again this is my opinion so don't hog tie and quarter me. Just doing what I can to keep it alive.

 

[victor3ranger]

Amazing job

 

[victor3ranger]

This is the only kind of ammo that I can make from nothing

 

[Mike Matteson]

This is the only kind of ammo that I can make from nothing

You build them on your own? I often wonder just how much it took to built one. It had to take some time to get it done.?

 

[victor3ranger]

You build them on your own? I often wonder just how much it took to built one. It had to take some time to get it done.?

I was taught when I was little. The more you handle the rocks the better you can read how they are going to behave.
I'm not as good as a lot of people but start to finish it takes about 45-hour with good stuff.

 

[Mike Matteson]

I was taught when I was little. The more you handle the rocks the better you can read how they are going to behave.
I'm not as good as a lot of people but start to finish it takes about 45-hour with good stuff.

Interesting: Anything out there to show how to? Look at what you need and the rock that will work?

 

[victor3ranger]

I think YouTube has a bunch of videos on it.

Quality rock is important so it fractures correctly and predictable.
Different cherts work differently, some work better after heat treatment.