300 saum to 7 saum

[Ivanna]

Since it’s so hard to find 7 saum brass I was able to get my hands on 300 saum brass. Problem maybe is after putting through the full size die no issues then through my Sinclair expander 7mm and no issues.
HOWEVER, when I measured OAL case length the 300 saum is shorter 2.0150. I measured new 7 saum ammo and OAL is 2.035.

So I checked the internet and SAMMI.
The 300 has longer neck than the 7 only by .020 approx.
The 300 has shorter body than the 7.
300 max case is 2.015 and for the 7 it’s 2.035

I did not know this but people are still necking the brass down.

Does this affect accuracy? When it gets fire formed in my chamber what will happen? Should I load with inexpensive bullets and powder just to fire form brass?

Thanks, pls help or should I junk this brass.

 

[Ivanna]

OR does anybody know where I can get 7 saum brass???
All the usual places like go big, corlanes, big barton, precision optics, nechacko, etc are all sold out.
It’s very hard to find. I guess I’ll use the 300 and separate from the 7 saum.
With its own load, powder and cheap bullets for the first fire form.

 

[dan belisle]

Since it’s so hard to find 7 saum brass I was able to get my hands on 300 saum brass. Problem maybe is after putting through the full size die no issues then through my Sinclair expander 7mm and no issues.
HOWEVER, when I measured OAL case length the 300 saum is shorter 2.0150. I measured new 7 saum ammo and OAL is 2.035.

So I checked the internet and SAMMI.
The 300 has longer neck than the 7 only by .020 approx.
The 300 has shorter body than the 7.
300 max case is 2.015 and for the 7 it’s 2.035

I did not know this but people are still necking the brass down.

Does this affect accuracy? When it gets fire formed in my chamber what will happen? Should I load with inexpensive bullets and powder just to fire form brass?

Thanks, pls help or should I junk this brass.

Neck it down, fire it in your gun, presto, it is now 7 saum brass. As for 7 saum brass, adg will put you on their list i think. You can also reform 270 wsm to 7 saum. More work, but there seems to be a lot more 270 wsm out there. - dan

 

[I Dont Care About You]

Thanks, pls help or should I junk this brass.

You want to junk brass because it is 0.020" short? You must have way too much money?

What is it that you imagine a 0.020" shorter neck is going to cause or do to the ammo?

In this day and age do people really have piles of inexpensive bullets, powder and primers to waste? Reference my first comment about having way too much money ....

 

[b72471]

7 SAUM Brass.
you can use the 300 saum brass.
I have used the 270 WSM, you can use 7 WSM or even 300 WSM brass, HOWEVER there is a trick to this, at the base to the top of web you have to remove .003 brass. So that requires calipers and removing .003 brass at the base in a drill press or small lathe.
Works for me and no shortage of SAUM brass.
enjoy.

 

[Ivanna]

Great suggestions I did not know about the wsm’s will have to try that.
I got name down for Adg hopefully they come for summer!
Thanks everyone!