New SAUM brass is .008" undersized on case head dimension.

[KMG]

Hey guys I recently purchased some 7mm ADG brass for a SAUM based wildcat. Upon general inspection & prelim measurements I realized that this brass has a case head of .5440" - .5445" & some recent fireformed Norma cases measure .5515" - .5520". My Virgin Norma brass is right at .5500". I've never run into this issue before & would like some imput on this issue. I've dealt with headspace case length issues but this variance seems extreme to me & possibly a miss run on specs. Thanks much.

 

[boltfluter]

Kmg,

By chance have you compared the Norma to Remington brass? I would assume the Remington would be the standard. I am running a 6.5 SAUM and have Remington and ADG brass and can take some readings for you if needed. Let me know.

Paul

 

[KMG]

Kmg,

By chance have you compared the Norma to Remington brass? I would assume the Remington would be the standard. I am running a 6.5 SAUM and have Remington and ADG brass and can take some readings for you if needed. Let me know.

Paul

I do not have any virgin Remington brass to check. If you could mic a few that would be great. Thank you. I run Norma on my other SAUM based wildcat & run it rather hard & haven't lost a case due to loose primer pockets. But with a .006" - .008" case head/web expansion upon fireforming I believe will just shorten the useable life of the brass. Kevin

 

[boltfluter]

Kevin,

Will get you some readings shortly when I am in the shop.

Paul

 

[tom]

Yes, I just began a 30 caliber project on that brass. Having no clue about 7 saum dimensions, I didn't catch it at first. I have 8 cases fire formed that I will keep shooting before moving on, but my guess is they will have premature failure. Everyone got all excited a couple years back when more brass manufacturers came to be. What I've seen is one can't get the metallurgy right and I had a friend about lose his face. And now one can't even get the diameter within a couple thousandths. I guess I'll reach out myself today and see if they are going to fix it in the future, but I'm pretty sure I just wasted a pile of money.

Tom

 

[6MMsteve]

can you make the brass from 300 wsm is it too far out of spec..never done it but it seems like it would work

 

[tom]

can you make the brass from 300 wsm is it too far out of spec..never done it but it seems like it would work

Lol, that was the whole point for me. I was looking for a wsm with better, tougher brass. The same lesson keeps repeating, if lapua doesn't make the brass, don't get your hopes up lol.


Tom

 

[bblackwell]

KMG,

The first 7SAUM brass ADG released back in Jan. had a case head measurement of .5452 …… I had a couple of concerns at first but never had an issue. I've since hammered that brass 8 times with a SAUM imp. and the primer pockets are still very tight.

Now if they would just make WSM.

 

[KMG]

I would use the Norma SAUM brass. I have some ADG & Norma already fireformed but have lost 3 out of 15 of the ADG due to loose primer pockets after only the 3rd firing with mild loads. The ADG has a larger capacity than the Norma hence the reasoning to use the ADG.

 

[DaveTooley]

.008" isn't that much. It may seem like a lot but it's the thickness of a skinny piece of paper wrapped around the head. As someone who has many tight base reamers it does not help with primer pocket life. The primer pocket is unsupported. It takes tougher brass to oppose higher pressures. With tight fitting brass all you end up with extraction problems without a perfectly matched sizing die.

 

[shoot4fun]

Lol, that was the whole point for me. I was looking for a wsm with better, tougher brass. The same lesson keeps repeating, if lapua doesn't make the brass, don't get your hopes up lol.


Tom

Funny how we generally accept ALL Lapua brass as the best there is. I know many good shooters and trusted reloaders that have had many of the same issues with Lapua brass of late. Most won't even do any measurements on their Lapua brass while they fuss over the slightest dimensional "issue" with any other brand.
I tend to see brass as automobiles. Some are 100% perfect off the line and others, well, not so much. Doesn't matter who's nameplate is on it.

 

[DaveTooley]

SAAMI specs
brass @.200" .5500" -.008"
chamber @.200" .5510 + .002"
ADG brass .5445" meets specs

 

[mikecr]

So how many firings would it take for the cases to finally fit your chamber as stable?
That is, with each firing causing H20 capacity & load density changes.
And by the time it's expanded so much, having broken all grain structure, it will be hard and hateful of sizing cycles. It will want to runaway into interference fitting/popping extraction more so than behaving like normal brass. You then size this harder brass more to fight it, risking cracking.

Next time you can measure your intended brass before filling out the reamer print.

 

[DaveTooley]

No problem if you have a properly dimensioned FL sizing die. The scenario of big chamber and small die causes all the problems. Fire forming is nothing more than a single reverse step in the case forming process. Not the beginning of the end of the world.

 

[mikecr]

No problem if you have a properly dimensioned FL sizing die.

This, w/resp to his chamber, or brass?

 

[DaveTooley]

Chamber
Fire forming brass to fit the chamber doesn't affect it's grain structure or hardness. But repeatedly moving brass work hardens it and it develops a memory. That's why minimal sizing works best. The only way to get tougher primer pockets is more strokes of the press forming the brass.

 

[KMG]

I contacted ADG & they returned my call later in the day. They mentioned that since my barrel is chambered for a wildcat, 338 Sherman Short, & it was a special headstamped run of brass to contract the case designer, Richard Sherman. Rich actually called me about the query. Rich as always is interested & eager to help with any issues that arise in any of his chamberings. Going to send some of the cases back to ADG for testing. So time will tell what they find out. Good to know that the designer of the SAUM case is one of the owners of ADG tho. I was told that the .5445" case head measurement is spot on with ADG's dimensions for that case. I'll post if there are any updates from ADG after analysis. Thanks for the input guys..

 

[mikecr]

Norma is right.

 

[whatwind?]

Lol, that was the whole point for me. I was looking for a wsm with better, tougher brass. The same lesson keeps repeating, if lapua doesn't make the brass, don't get your hopes up lol.


Tom

anymore developments with this project and brass?

 

[rardoin]

anymore developments with this project and brass?

I can speak to the nature of the ADG brass produced for the Sherman Short mag variant of the SAUM case. I also found it near 0.008" undersized at the .2" datum compared to the reamer for that case. I also spoke with Rich concerning this and he said it will be fine. After 3 firings on 24 of the 7 SS cases they extract normally and the primer pockets have hardly changed in diametric dimension. It is great brass.