7 SAUM, am I on the right track here?

[WhiteRubi]

Hey folks, I'm in the planning phase of a 7 SAUM build, on a short action. I've kind of settled on an Anti-X short action. They offer it on a SA UM XL Mag cut. It states that the xl mag cut is only to be used with the Unknown Muntitions XL box. I'm planning on running the 175 Berger Elite at around 2.825 but would like the option to shoot 180s if I want. I guess what I'm after is this, the Anti X in the SA Mag UA XL Mag cut, and the UM box,where will i be on max cartridge length? I THINK the UM box limits you to 3.15. Is this setup a good match for maximizing the 7SAUM in a short action?

Then I get into freebore and chambering nuances. So if there is any input ther, that would be great. Thanks fellas

 

[StumpyJohnson]

In my short experience with the 7 Saum, it may be better suited to a long action if you're looking to shoot those longer bullets, and not have them jammed down into the case. I think you might be seeing OAL's in the 3.16 territory.

I'm Playing with a 7 Saum built on a Tikka LA that has +.200 of freebore (so I'm told, I bought the barrel from a private party and have not seen the chamber print). My COAL is at 3.165 at .025 of the lands with a 180 grain eldx.

 

[WhiteRubi]

understood. In my mind, anyhow, at what point, if you go long action, do you abandon the SAUM and go PRC, or 280 AI, etc?

I really think I'd stay in the 175 and under in a bullet, but the option to run longer if I wanted, is intriguing.

 

[StumpyJohnson]

As a side note. I have a 7 Saum in a ARC nuke SA, I shoot a 160 gr CX mono bullet out of it. That bullet I think is as long or longer than a traditional bullet in the 170-180 grain weight. I stuff it way down into the case and it shoot 10 shot groups at just under 1 moa all day. But that might not be the norm though if "donuts" from in that brass it may start to perform poorly, time will tell.

Just don't skimp on barrel length as velocity will drop off. I think a 180 gr bullet will top out in the 2700 fps range on a 20" barrel. 22" seems like the shortest you'd want to go.

All this is based on 2 barrels for me, so there's your grain of salt.

 

[Browninglover1]

3.15" is plenty for a SAUM with 180s. I have mine built on a medium that allows 3.20" but 3.15" would work just fine.

 

[Rick Richard]

Why not go with the Medium action. There will be no doubt and you can shoot all the way up to the 195. Just a thought and what I have with the Anit-X.

 

[jja600]

I had a gunsmith build a custom 6.5 SAUM on a long action for hunting. It feeds flawlessly from a Hawkins hunter mag with the spacer. I have 200 rounds down the tube with no issues. I wanted to have options when I re-barrel.

 

[StumpyJohnson]

understood. In my mind, anyhow, at what point, if you go long action, do you abandon the SAUM and go PRC, or 280 AI, etc?

I really think I'd stay in the 175 and under in a bullet, but the option to run longer if I wanted, is intriguing.

Valid question. I've heard good things about all of them. I think there a touch of magic in 7saum. It's efficient. It runs on powders shared by other cartidges I shoot. Why does anyone pick any cartridge really?


I think the question is more, why do want to run long heavy bullets in a short action cartridge? Mind you, I do it too. I'm not accusing you of anything.

Is this going to be a ultralight Backcountry elk hunting rifle?

 

[FEENIX]

Hey folks, I'm in the planning phase of a 7 SAUM build, on a short action. I've kind of settled on an Anti-X short action. They offer it on a SA UM XL Mag cut. It states that the xl mag cut is only to be used with the Unknown Muntitions XL box. I'm planning on running the 175 Berger Elite at around 2.825 but would like the option to shoot 180s if I want. I guess what I'm after is this, the Anti X in the SA Mag UA XL Mag cut, and the UM box,where will i be on max cartridge length? I THINK the UM box limits you to 3.15. Is this setup a good match for maximizing the 7SAUM in a short action?

Then I get into freebore and chambering nuances. So if there is any input ther, that would be great. Thanks fellas

The SAUMs and WSMs thrive in the 3.2" plus range. So, if you want to take full advantage of its capabilities, especially when you are thinking of throating it longer, etc., consider the action that will accommodate the 3.2" plus COAL. Good luck!

 

[lancetkenyon]

3.10" should be plenty long for a 7SAUM w. 175s. 3.200" XM would work great too. But even a true 2.980" SA work for 7SAUM and all but the heavy 195/197s. SAAMI FB is what will dictate seating depth as much as mag length.

I run a 24" 7SS w. 184 Hybs in a true 2.980" SA WSM box. They fit fine.

I have loaded for a few 7SAUMs w. 160, 165, 168, 175, 180s in 2.980" SA mags, and they run great.

 

[MallardAddict]

The 7 saum will work fine with 180's in an SA 2.98 mag like Lance said. If I was buying an action expressly for the 7 saum it would be a medium length 3.2" which is exactly what I did for my 7 saum build.

 

[WhiteRubi]

We have it covered, I think. So a new question. In a short action and the UM bottom metal and their mag, I can load to approximately 3.15"
I know, now, that is fine. So if i plan to mainly shoot 168 and 175, and MAYBE 180s, how do I address freebore when getting it chambered?

 

[warrbuk]

We have it covered, I think. So a new question. In a short action and the UM bottom metal and their mag, I can load to approximately 3.15"
I know, now, that is fine. So if i plan to mainly shoot 168 and 175, and MAYBE 180s, how do I address freebore when getting it chambered?

You cant use that bottom metal / magazines that get you 3.15 with just any action. The action has to be cut for it and most are not. I know the BAT Vespar is or can be and the Defiance can get the special cut. My Kelbly was not compatible

 

[StumpyJohnson]

We have it covered, I think. So a new question. In a short action and the UM bottom metal and their mag, I can load to approximately 3.15"
I know, now, that is fine. So if i plan to mainly shoot 168 and 175, and MAYBE 180s, how do I address freebore when getting it chambered?

I'd load a 175 to the length you want, and ask for the freebore to match your bullet jump/jam preferences. A 168 would have a bit more jump, and a 180 a bit less. I'd think it'd be in the CBTO +.025 ball park. Also, recommendations from your smith is always a wise idea.