New to 7WSM... help?

[wilkup]

Got a new rifle coming and was hoping I could get some information for hunting rounds for this load.

It's a Bartlein 24'' barrel with custom radial brake on it. I've got my eye on the 168gr Berger Hybrid and the 140gr VLD. Any thoughts as to what works best with this round? I currently have RL33 and MagPro powders in my stock pile. Should I be looking at anything else?

 

[Varmint Hunter]

I've shot the Berger 180 VLDs with great accuracy and good terminal performance when my barrel was new.
With nearly 1,000 rds down the tube it now prefers the Nosler 160 Accubond with a max load of 7828ssc and a Fed 215M primer.

Biggest issue with the 7WSM is a total absence of brass for the last 2 years. Quality brass was never available but even the usual Win brass hasn't been available for quite some time.

 

[wilkup]

Biggest issue with the 7WSM is a total absence of brass for the last 2 years. Quality brass was never available but even the usual Win brass hasn't been available for quite some time.

That is good to know! I haven't had it chambered yet but just checked and saw Midway has Nosler and Norma brass available for the 7mm SAUM which was completely unexpected! I thought the SAUMs went the way of the dinosaurs... is there new interest in the 7mm SAUM?!
I will most likely chamber for the SAUM knowing there's brass available there and give up a little powder capacity/velocity.

 

[wilkup]

Another option would be to neck up 270 WSM brass, right?

 

[Varmint Hunter]

Another option would be to neck up 270 WSM brass, right?

You could convert 300 WSM or 270WSM brass but the case head-to-datum line on the 7WSM is longer so the conversion isn't as simple as it seems. I've done the conversion and it's a pain.

You may also consider the 7-300WSM. This way you could simply neck down readily available, high quality 300WSM brass. This is probably the route I will go when I rebarrel.

The RSAUM has slightly less case capacity then the 7WSM and some shooters prefer it for that reason. I too am surprised that any of the SAUM cartridges have lasted this long.

 

[wilkup]

I'm not interested in a wildcat chamber - 7mm/300WSM

Option 1
So I could resize the neck on 300WSM shells to 7mm, using Norma brass and fire-form to the WSM chamber.

Option 2
I could give up some speed but skip the neck-sizing and fire-forming by going with the 7mm SAUM and purchase perfect Norma with no headaches.

What sort of speeds could I obtain pushing Berger's 140gr VLD or 168gr Hybrid out of a 22" barrel? How about 23"?

Is the SAUM with a 22" barrel the ballistic equivalent of the 280 Ackley?

 

[Varmint Hunter]

Your option #1 would require you to partially size the neck of 300WSM brass while creating a false shoulder on the neck. This is necessary to create proper headspacing while the shoulders are being blown forward. It's a PIA if you ask me but some 7WSM shooters are happy to do it. It is a waste of barrel life IMO and is one less use of every case. And, that assumes that it works as expected on the first firing. It would also result in some case wall thinning but that may not be an issue. Who know?

RSUAM seems like a much more sensible approach as long as the brass is available. You could buy enough brass up front for the life of the barrel and have nothing to worry about.

How about this for an option - Chamber in 270 WSM? The bullets are a mere .007" smaller in diameter then the 7mm. Quality brass is readily available. The cartridge has a wide following and should be around for some time. Your rifle will shoot a wee it flatter.

There, I think we've solved everything.

 

[wilkup]

How about this for an option - Chamber in 270 WSM? The bullets are a mere .007" smaller in diameter then the 7mm. Quality brass is readily available. The cartridge has a wide following and should be around for some time. Your rifle will shoot a wee it flatter.

There, I think we've solved everything.

I already have the Bartlein #3 5r barrel in .284 caliber with a 1-9" twist.
I tried to order a fast twist (1-8") from them but was told it'd be 4-6 months on wait from the as well as most other barrel makers. I wanted to shoot the 165gr Matrix.

SAUM may be the way to go with this build. It'll be enough to hammer anything in the lower 48.
Thinking about having the smith knock the barrel down an inch or two and try out the new Hornady ELD X in the 162gr size.
I'm thinking I could push theELD X around 3000FPS
Keep things nice and light for an all-around boom stick =)
Maybe get a hold of some 120gr TTSX and scoot those along at some screaming velocities, in the neighborhood of 3400FPS.
Between those two bullets I've got big and small covered down here, assuming those Hotnadys are as great as everyone keeps saying =)
Build parameters have changed since beginning, but I'm excited to get this thing completed. Once I decide on barrel length, it's getting fluted and then sent out for a super light custom stock!