Gunsmithing 7mm WSM build info

hoguer

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Looking to build a 7WSM coming up, and was wondering what people were having the best luck with? twist rate/ bbl length. etc. Any input would be much appreciated. Thanks
 

USMCj

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Re: 7mm WSM build info

Barrel length - 28"
Twist - 1/8.7
Bullets - Bergers and A-Max's

Whatever you end up doing, get your barrel Melonited after a 5-10 shot break in. While I love my 7WSM, it eates through the throat at an alarming rate. And meloniting the barrel or barreled action helpes throat stay where it is. I just wish I knew about this when I had my rifle built.

Anyway, here is mine. It might give you some ideas.

Surgeon RSR WSM action w/20moa double pinned steel base and double pinned .300" recoil lug.
Rock Creek 28" fluted MTU contour barrel, 1/8.7 twist
Badger Thruster brake
Timney trigger @ 1 pound
McMillan A5 stock, pillar bedded
Seekins WSM DBM w/3 round mag
Harris BRM-S bi-pod wth podlock and pod claws
USO SN3 3.8-22x58mm scope, mil/mil
TPS 35mm rings
USO rail mounted anti-cant

DSC04549.jpg


DSC04552.jpg


IMG_0290.jpg
 

468shot

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Re: 7mm WSM build info

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Papagrizzly</div><div class="ubbcode-body">1 in 9 twist barrel if you plan on using 180 gr bullets. Faster twist if use the 168s. Depending on type of gun, 28" to 30" barrel. </div></div>

Why do you recommend a faster twist for a lighter bullet?
 

USMCj

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Re: 7mm WSM build info

Because he doesnt know what he is talking about.

You may want to go with 1/8.5 or 1/8.7 for the new Berger bullets that are coming out. 1/9 might have trouble stabilizing them.
 

CWCruiser

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Re: 7mm WSM build info

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 468shot</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Papagrizzly</div><div class="ubbcode-body">1 in 9 twist barrel if you plan on using 180 gr bullets. Faster twist if use the 168s. Depending on type of gun, 28" to 30" barrel. </div></div>

Why do you recommend a faster twist for a lighter bullet? </div></div>

I was wondering the same thing, guess i got lucky with mine liking the lighter bullets. FREAKY!!!!!
 

Papagrizzly

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Re: 7mm WSM build info

Fixed it - went the wrong way
frown.gif


I have a 9 twist barrel and a 9.5 twist, amongst others that I have experimented with. The 168s shot well with both the 9 twist, but better with the 9.5. I also have an 8.75 twist that likes the 180s.
 

Papagrizzly

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Re: 7mm WSM build info

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: USMCj</div><div class="ubbcode-body">Because he doesnt know what he is talking about.
</div></div>

Man - you are quick to make a judgement about someone!
 

19Scout77

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Re: 7mm WSM build info

22.5" bartlein 9 twist on one; 24" 9 twist rock on the other. Short one loves 162s, longer one 175 smks.
 

468shot

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Re: 7mm WSM build info

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Papagrizzly</div><div class="ubbcode-body">Fixed it - went the wrong way
frown.gif


I have a 9 twist barrel and a 9.5 twist, amongst others that I have experimented with. The 168s shot well with both the 9 twist, but better with the 9.5. I also have an 8.75 twist that likes the 180s.</div></div>

Alright, I figured you meant the other way I just wanted some clarification.

ffhogue,

FWIW I was wanting to know the same thing, I did a few searches and decided a 1/8.5 twist would be the best. It will stabilize just about anything you will shoot out of it. Still haven't come to a conclusion on barrel length for what I want to use one for though....
 

Papagrizzly

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Re: 7mm WSM build info

Yeah - very much like guitar notes. A high note means low on the fretboard and a low note means high on the fretboard. Have to watch myself, or take a black eye within minutes
smile.gif


Thanks for questioning it.

Oh - by the way, also have an 8.4 twist barrel that did not do as well as the 8.75 and the 9 twist for the 180s. I do not shoot the 168s anymore. Like the 180s. What's your build going to be?
 

idahoshooter

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Re: 7mm WSM build info

Does anybody have experience with a shorter barrel then 26+? Looking for a hunting build and would like to stay as short as possible. Could you get the 162 amax to 3000 fps at 24 inches, Id be happy with that.
 

PCR

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Re: 7mm WSM build info

If your going to load longer bullets, 180 berger, 162 amax, you may want to consider including a magazine system in your build that will give you more room for OAL. Seekins makes a DBM with over 3.1" OAL or you can use a Wyatt box which would be cheaper. You'll need to have the rear of your feed port milled back about .015". Standard M700 SA magazine is short and you'll be stuffing bullets deep in the case. Something to think about before you get started.
 

468shot

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Re: 7mm WSM build info

Not trying to hijack the thread, but I was looking at building one for a LR varmint/hunting rifle. I don't mind a heavy rifle, but a long tube gets a little old.. I think building off of a surgeon with a heavy palma fluted in a manners t4a and seekins dbm would be the ticket. I just don't know how short I could get away with and still get the 180's to 1400 yds. Also, toying with the idea of a gain twist barrel, but can't find much info on them in 7mm.
 

USMCj

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Re: 7mm WSM build info

As far as gain twist goes, I wouldnt mind trying out a 1/9-1/8.5 barrel, but thats as much as I would want it to gain.

And 24" would be the min. I would go if you want to shoot the 180's.
 

hoguer

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Re: 7mm WSM build info

As of now, im wanting to do my own build so im leaning towards a Savage action at this time, along with another ABS wrapped bbl. I know other actions are probably better suited, and money aspect is not a problem at all, just wanting to play a little myself. I have many custom built rifles, but i want one i built.

Looking at:

Savage Gen2 Short Action
Evolution trigger
30" Satern 1-8.7 w/Roedale Precision Muzzle Brake
Mcree Precision Folder chassis (does AI have a WSM mag???)
Murphy Precision 20moa Base
Seekins Precision Rings

total build cost: Approx $2200+
 

USMCj

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Re: 7mm WSM build info

With a 24" barrel, you can get the 162's over 3K fps, and 2850-2900 for the 180's, maybe.
 

19Scout77

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Re: 7mm WSM build info

22.5" will fling 162s at 2950-3000 with a little load development. 4831 is your friend!
 

468shot

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Re: 7mm WSM build info

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: USMCj</div><div class="ubbcode-body">As far as gain twist goes, I wouldnt mind trying out a 1/9-1/8.5 barrel, but thats as much as I would want it to gain.

And 24" would be the min. I would go if you want to shoot the 180's.</div></div>

Thanks for the info. I was thinking the same thing on the gain twist. It seems that when people put too much gain in the barrel is when they start having issues. I think a 1/9-8.5 gain twist at 25" has some potential.
 

Handloader

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Re: 7mm WSM build info

I built mine on a long action savage, with bottom metal from Kevin Rayhill at Stockade guns. The long action AI mags give plenty of room to chase the throat erosion. I am still up in the air about Melonite for the barrel, but am interested.
 

Papagrizzly

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Re: 7mm WSM build info

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ffhogue</div><div class="ubbcode-body">I have a uso sitting on a shelf waiting for a gun. </div></div>


You'll have a wonderful rig when done. USO are great scopes (stating the obvious).
 

hill billy

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Re: 7mm WSM build info

Not to raise this from the dead but I need to pick between an 8.5 and a 9 twist in next day or so. For the 180 VLD's anybody have a preference that will be more versatile with the 162's? I am assuming the 9.
 

flyboy

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Re: 7mm WSM build info

I don't see why a 8.5 wouldn't work with the 162's. 9 twist is pretty much an industry standard and works with bullets down in the 140's so at 8.5 should work for your 162's.