7 Saum Brass

[jamesh]

Most standard 7SAUM reamers are .321-.322 for neck diameter so it seems the ADG brass would work well there. Curious what are minimum chamber/brass clearances people are running for no turn SAUM necks?

My no turn 7 SAUM reamer is .318. It was ground for early Nosler 300 SAUM brass necked down to 7mm. That isn't enough for the ADG brass, you will need at least a 3.20" neck for it if you don't want to turn necks.

 

[TZaun]

Loaded rounds with Norma brass are .315-.316 in my experience, if I remember right the neck walls are around .0155-.016 so it appears that the ADG is just slightly thicker (at most .0005 on neck wall).

The ADG loaded rounds should be .316-.317 but maybe someone can verify this?

I just stuffed a 180 Hybrid in a new ADG case and mine measures .3155".

 

[Dubbo]

My no turn 7 SAUM reamer is .318. It was ground for early Nosler 300 SAUM brass necked down to 7mm. That isn't enough for the ADG brass, you will need at least a 3.20" neck for it if you don't want to turn necks.

What was your loaded round diameter in the necked down brass?

 

[jamesh]

What was your loaded round diameter in the necked down brass?

.316" for 300 Nosler brass. My loaded ADG brass is around .3175, I don't recall the exact measurement but over .317

 

[Dubbo]

So far for the ADG brass loaded rounds it appears between .3155 to .3175

 

[PeteB]

So far for the ADG brass loaded rounds it appears between .3155 to .3175

Gday Gents, i am just in the process of ordering a reamer for a 7 SAUM, the owner will be using ADG brass no turn only, and i just needed confirmation on some dimensions for the reamer print i have in mind.
At the .200"line .550", .320" neck, freebore .188" for using 184 and 190 hybrids?.
do i need to go .321" on the neck? or tighter at the .200" line, say .549"?
Owner will be using Wilson FL bushing die.
Any help would be much appreciated, thanks, Pete.

 

[jamesh]

I think those will work. The ADG brass is small at the. 200 line .5455. If you grind the reamer to fit the brass you will need a custom resizing due. Loaded round necks on my ADG 7SAUM brass measure. 317 so the .320 neck should work. edit to add I'd go with a .230 leade. my reamer is .201 and it's short for the 190 Hybrids.

 

[rardoin]

I have a 7 Sherman Short which has the SAUM as the parent case. ADG makes headstamped brass for it and it measures .546 at the .200" line/the reamer measures .551". I have zero issues with sizing the cases down to a nice loose fit in the chamber in spite of my concerns. I have 4 firings on much of it.

 

[Dubbo]

So I have used ADG brass in my 7mmSAUM since posting, my loaded rounds are right at .3165”, which is right in the middle of the info I got on here before buying brass. Since I run no turn necks I did have my gunsmith open up my neck from .319” to .321” with a new reamer. I do like ADG brass over Norma.

 

[Kurz]

SAAMI is 0.550 for the cartridge and 0.551 for the chamber.

The ADG and Gunwerks brass that I've measured was 0.546 or less, if memory serves.

I guess whether or not that is "under" or "smaller" is up to you.

Here is the SAAMI drawing for the 7MM SAUM:

Note in the lower right in BOLD TYPE it states "unless otherwise noted BODY DIA. -.008 (0.20)".

Interpreted to mean a diameter of 0.550 - .008 should equal a minimum diameter of 0.542". So anything measuring between 0.542" and 0.550" falls within SAAMI specs.

Enjoy!

 

[Boatschool02]

Yes.
Thank you.
Original post(s) & consequent semantics updated on page one, back in January to reflect this understanding.
0.008 is a country mile in this game.
Recommend measuring brass on hand and heeding @Alex Wheeler's advice on finish and sizing reamer relationships.

 

[whatwind?]

I just measured Virgin ADG, Bertram, and Hornady 6.5 rsaum brass and it’s all .5442-5 and fired RP brass measured .550 b/c reamer is .551

how tight are you going for single shot action?

Yes, new reamers and chambers will add up if it is a problem, sounds like Robin is doing just fine though

 

[rardoin]

I just measured Virgin ADG, Bertram, and Hornady 6.5 rsaum brass and it’s all .5442-5 and fired RP brass measured .550 b/c reamer is .551

how tight are you going for single shot action?

Yes, new reamers and chambers will add up if it is a problem, sounds like Robin is doing just fine though

I had two tight bolt lifts out of over 200 rounds this weekend at the La LR match and no clickers with the fifth firing on -0.008” under chamber diameter ADG brass. My concerns were unfounded. That being said with more firings I may start to see clickers. We’ll see. I will see what the team at JGS says this week when I spec a new reamer for the 7 SS.

 

[rhovee]

If you have a min spec saami reamer and use tough brass like ADG, you’ll end up getting clickers if you are using standard dies. I have (4) custom dies on the way for my saum chamber that Alex Wheeler chambered. I have tried Redding and Hornady dies and neither size the web enough

 

[moondog]

If you have a min spec saami reamer and use tough brass like ADG, you’ll end up getting clickers if you are using standard dies. I have (4) custom dies on the way for my saum chamber that Alex Wheeler chambered. I have tried Redding and Hornady dies and neither size the web enough

Try a Wilson full length bushing Die. That's what I was using when I was running a 7SAUM. Don't remember the numbers, but it sized the web .0015 if I remember correctly. I was using Norma 300 saum brass necked down.

 

[whatwind?]

would cutting the sizing die off by some (.015) help?

 

[rhovee]

I would think that if you cut the die off, headspace would be to short

 

[PeteB]

would cutting the sizing die off by some (.015) help?

Thanks for the replies Gents, got some very useful info there. I went with .550 @ .200 line, .321 neck diameter and a .230 freebore for the ADG brass and 190 B hyb. Will also try the wilson bushing FL die,
cheers Pete

 

[ShaunW]

I just reached out to a gunsmith tonight for my first 7 SAUM. I wanted @Alex Wheeler to do the work but I guess he’s so buried that life sucks and I was turned away which I understand. However I want to make sure I’m set up correctly with sizing die and avoid problems with clickers. I plan on using 180 hybrids with ADG brass. I was thinking about using the LE Wilson die and then consider having an insert made for my Warner tool die BUT I may hold off on the custom insert until Alex can do the work on the second barrel. The primary use will be long range fun snd not a hunting application. So if anyone has advice on a resizing die and then if I need to making any requests on the chamber work considering my components and application I will say thanks in advance. Oh this will be on a Impact short action.

 

[rhovee]

Lots of people have reamers for short action saums. .090 freebore is about right. .551 on the base can cause the clickers. If a min sammi reamer is used, have some polished out to get .5525 ish. Should allow a standard die to work with no clickers. Hornady bushing die was the smallest at the base.