7 WSM Build

BillyBushCook

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Mar 18, 2015
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First a quick Intro.
I'm from Aus, 46yro, a shooter of about 35yrs. The past few yrs have been learning the ropes of LR by doing a little F Class along with some Gongs out to 1000yds on private property & LR hunting to 600yds. (Goats mainly)
I began with a Factory Howa .308 varmint (long time Howa owner/fan) which I set about tuning to within an inch of it's life with custom made Redding Comp Dies (made my own sleeves to suit my chamber), Pillar bedded into a boyd's Thumbhole & a hand made removable bag rider.
The rifle still shoots very well after about 2,000 rnds, 75% of the time it is 1/2" or less, 5 shot 100m groups but does throw the occasional flier so I have a Benchmark barrel here ready to go on it.

So basically I have been using a hunting rifle for f Class & now I would like an F Class Rifle to take hunting! (it won't be getting carried too far)

For some time now I have had a hankering to build a full custom LR rifle & the 7WSM cartridge has always appealed to me even though they are rare over here.
Toying with Bullet lengths in Acad (I'm a Machinist by trade now re-schooled as a Mech Engineer & Draftsman) & it appears as though a reasonable O/A length of the round set up to get best performance is going to end up around 3.120" (using a 162gr Amax as a starting point)
This leaves me with a Dilemma.
Too long for a std short action & I would like to avoid using a long action.
I figure I can get a 7mm SAUM to work in a modified factory SA with a Wyatt extended Mag Box with my preference being another Howa action (for exchangeability on parts, mounts & stocks etc with my current rifles) or a Rem 700 action but the WSM would not be feasible in either of these.

The down sides to this:-
It will always be a cop out with the SAUM because I have my heart set on the WSM for the extra speed.
There are not many howa's over here with the WSM bolt face. I know I could modify a .308 bolt face but to pic up a Howa in .300WSM & re-barrel it would be an easier option & much cheaper than custom.

Now, the only reason I am considering the Howa SA for this purpose is because I like to use Hilver/Lynx 1pc mounts for three reasons.
1. They help stiffen up an already stiff factory action.
2. They are windage adjustable so I can be sure to set the scope up well centred.
3. I already have one on hand & it suites both Rem & Howa SA's.

The actions I would most prefer are in this order.
1. Full custom, robust/stiff Top loaders.
2. the Howa SA
3. rem 700 SA

Now the problem of availability & price.
The most appropriate option I can see for a WSM would be a Defiance Deviant mid length action.
The problem being that I was quoted $2300 Au for one over here.
The Defiance rebel XM action might even be better suited to the length I want but I'm yet to find out how long the mid length action is.
can any one help?
Either way these are going to extend the build cost out to around the $5,000Au mark.
(Benchmark barrel, GRS Stock + a scope & trigger) where I could build off a Howa for 1/2 that..........is it really going to shoot 2x as good? I doubt it.


Question.
Are their any other custom Actions (apart from Defiance) that will fit up to std Rem 700 SA stocks, scope mounts etc, that can handle an O/A case length of say 3.2" or be better suited to this build?

regards, Mick.
 
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jrsolocam

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This isn't an answer to your question, but, is 7 wsm brass readily available there?
 

BillyBushCook

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Mar 18, 2015
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Wouldn't say readily but it is available.

I can make forming dies if I have to anyway.

There are a few 7WSM's about but the .270 & .300WSM's while not as popular as main stream cals are still more numerous than the 7mm from what I have seen.

Mick.
 

foreign

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I would lengthen the mag in the semi short action. That's what I did so I can seat 208amax way out in 308. Just extend the feed rails back. Then cut the magazine and add a filler piece. Ill measure mine when I remember
 

foreign

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My mag box can take an oal of 83mm. Feeding is fine, ejection of live round is awkward. But could mill out little radius of bullet tips if needed
 

just country

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morning, 7mmwsm held the world record for smallest group at 1000yrds, held by a gentleman from Britian.

The brass is very hard to fine. the cartridge has very short neck. the receiver rails will have to b opened for feeding. I fire mine single shot. I have mine built on rem. 721 action la,27.5" Mcgowen barrel, timmey trigger, a5 stock, vais muzzle brake. barrel crowned.

did some serious handloading to fine a magic load. personally I would think about another cartridge. the 7mmSTW has a very good reputation for long range shooting. If push comes to shove on the location on brass for the 7mmwsm. I will rebarrel to a 7mmSTW

Hope this helps

just countrylightbulb
 

BillyBushCook

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Mar 18, 2015
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Not a big fan of the long narrow powder columns in the typical LA mag cartridges.

Much better efficiency in the short magnums & efficiency often goes hand in hand with inerrant accuracy & ease of tuning.

With the availability of .270 & .300WSM brass, I don't see a big issue with forming my own from these two.

If it is then the 7SAUM will become my next pick.

If I were to go with a LA Mag, I might as well just go with the 7Rem Mag.

As far as ballistics go.
Working from memory when I last looked into it. (of the 3 cartridges, WSM, SAUM & Rem mag)
The WSM tops the list for velocity.
With the Rem mag next but uses an extra 4gr of powder for 50fps less performance.
Then the SAUM falling 100-150fps behind that again.

Mick.
 

jrsolocam

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If you are comfortable forming your brass go for it. Mine is a Borden and I'm shooting single shot, but a 180 at 2950 isn't anything to sneeze at.
 

BillyBushCook

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Mar 18, 2015
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Was trying to edit this just after typing but our work system then blocked me.:rolleyes:

As far as ballistics go.
Working from memory when I last looked into it. (of the 3 cartridges, WSM, SAUM & Rem mag)
The WSM tops the list for velocity.
With the Rem mag next but uses an extra 3gr of powder for 50fps less performance.
Then the SAUM falling 50fps behind that again.

Mick.
 

jrsolocam

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I don't know if the wsm tops the RM for velocity...I'd say more like it equals it. Anyway its close...I'm just disappointed Winchester decided to quit making brass for what? 3 years? It is a great little round for sure.
 

BillyBushCook

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Mar 18, 2015
Messages
10
I am a 7 wsm guy love it but I would build a 7x300 wsm.
You got me looking at this & upon doing some more research I'm now leaning back towards the SAUM again.

It appears the 7WSM may be a little hard on barrels but the SAUM is a little more forgiving. Mostly due the neck length.

Also stripped my .308 down to measure up the pillars so I can make a few more for people who I have offered some & in the process had a good look at what was possible with regard to extending the mag back & modify the bolt stop.

It looks feasible for me to extend the Howa back to about 3.120" (making my own mag box)
Still a little tight for the 180 Bergers or 162gr Amax's in a 7WSM but it gives me plenty of room for the SAUM. :D

Now looking at picking up a cheap 2nd hand Howa SA for a couple of hundred & tear into it with the mill.
At least that way I can sell off the barrel, scope & stock to make the action almost a freebie.

Mick.
 

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