rechamber a 270WSM to 7mm WSM

Discussion in 'Long Range Hunting & Shooting' started by Shootin4fun, Jun 9, 2012.

  1. Shootin4fun

    Shootin4fun Well-Known Member

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    I'm a newbie to building up a custom or semi custom rifle so please forgive me if this is a dumb question.

    I want my next rifle caliber to be 7mm WSM and I like the Vanguard S2, but they don't make it in 7 WSM. I've considered 270WSM, but want the better ballistics of the 7 WSM for LR. (Am I splitting hairs, considering I'm not in any formal competitions?)

    The V S2 does come in 270 WSM, but I'm wondering what would have to be done, and if it is plausable to rechamber it to a 7WSM. Obviously a new barrel at around $350 + mounting for starters.

    I've also read the articles on building a low cost LR rifle but it seems like I would have to buy more parts and integrate them; action, trigger assembly, bottom metal, barrel, stock, and what else? This sounds more expensive than a $485 + 350 + service to rechamber and rebarrel.

    Thanks for any advice and not thowing dead squirrels at me!
     
  2. Derek M.

    Derek M. Well-Known Member

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    The 7WSM is an excellent caliber. Why it is not more popular I have no idea. That said, my smith tells me that the ones he has built for many customers have reported short barrel life. So, keep that feedback in mind.
     

  3. Shootin4fun

    Shootin4fun Well-Known Member

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    Thanks Derek. I have read about relatively shorter barrel life in 7mm WSM but I'm wondering if the same is true with 270WSMs. If so, I might as well go ahead and get a 270WSM and THEN rechamber to 7 when its burned out. That should give me 800+ rounds of practice before I move on up and farther out. :D
    It seems the 7WSM is gaining popularity. Look on AccurateShooter; there are some good articles and links there.

    This is harder to decide on than choosing between which sports car to buy! (not buyin one, just sayin')
     
  4. 7 loader

    7 loader Well-Known Member

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    A 270 cal should burn a tube as fast or faster than a 7mm. I have 1500 rounds through my big 7 now and it still shoots great. I will retube soon, as my gun has a factory on it.
     
  5. bigngreen

    bigngreen Well-Known Member

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    Why not enjoy the better ballistics that the 270 WSM can bring to the table? Matrix ballistics bullets has two bullets that fit the LR application a 165 gr and 175 gr VLD with a g7 BC of .650+ and Berger is working a 170gr .703 BC bullet.
    Best to start with the 165 which will stabilize with the slowest twist barrel. Barrel life runs about 1200 rounds.
     
  6. MachV

    MachV Well-Known Member

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    Duck........Nuthin personal I just like throwing dead sqirrels:D

    I want my next rifle caliber to be 7mm WSM and I like the Vanguard S2, but they don't make it in 7 WSM. I've considered 270WSM, but want the better ballistics of the 7 WSM for LR. (Am I splitting hairs, considering I'm not in any formal competitions?)
    Yep your splitting hairs=The accuracy of the individual barrel will make a bigger difference than the BC of the 270 vrs 7 @ 600 yards and your wind reading ability will make a bigger difference @ 1000
    The V S2 does come in 270 WSM, but I'm wondering what would have to be done, and if it is plausable to rechamber it to a 7WSM. Obviously a new barrel at around $350 + mounting for starters.
    I bet your going to double the cost of the gun just to have a 7 vrs 270. Shoot the 270 out and REBARREL then??

    I've also read the articles on building a low cost LR rifle but it seems like I would have to buy more parts and integrate them; action, trigger assembly, bottom metal, barrel, stock, and what else? This sounds more expensive than a $485 + 350 + service to rechamber and rebarrel.

    Stop reading and srart shooting, not to be mean but your gonna find out relitivly quick that sporter weight V2 is tricky to shoot longrange with........

    I've got a 7WSM varmint contoured barrel comeing for an old Savage action that already has a tunable trigger and suitable stock. I paid $350 for the gun years ago and shot out the 6.5-284 barrel than came with it, the barrel is a $174 prechambered/prethreaded Shaw that I'm betting/hopeing is MOA out to 1000??

    Short barrel life for a compition gun? 99% of shooters will not truely shoot out a barrel:rolleyes:

     
  7. WildRose

    WildRose Well-Known Member

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    The .270 doesn't bring better ballistics to the table.

    Even staying with the Matrix bullets their hunting VLD's in .284 have BC's of 168gr-.713 and 180gr .807.

    As for barrel burners any of these are going to burn barrels quickly if you run max weight bullets and max charges to maximize velocity.

    Back off of the maximums a bit and barrel life is extended greatly.
     
  8. MachV

    MachV Well-Known Member

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    I just looked the V2 does come in 7maglightbulb
     
  9. bigngreen

    bigngreen Well-Known Member

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    The Matrix bullets won't make that BC, the 7mm 190 Matrix VLD runs right at the 180 Berger and the 7mm 168 Matrix won't run with the 168 Berger because it's not as aggressive design. You can run any of the highest BC 270 bullets 3000fps+ with the 270 WSM without much issues, the Berger with .703 BC in the mid 3000fps ain't to shabby at least till we see the 7mm 195 Berger :D
     
  10. WildRose

    WildRose Well-Known Member

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    You're just punctuating my point. I was just staying with what Matrix advertises for their BC's since that was the brand he was discussing.

    Sure if you compare bc's of the bottom end of one caliber's weights against the top end of another caliber's weights you can find some higher BC bullets, but you won't do it when you compare apples to apples vs apples to marshmallows.
     
  11. bigngreen

    bigngreen Well-Known Member

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    The 168 and 180 7mm Berger with the 190 Matrix compared to the 165, 175 Matrix and 170 Berger in 270 cal is as apples to apples as you can get, both are the top end for both cals and all but the 168 7mm Berger run a BC between .650 and .703. The BC's for the 270 cal Matrix are actual field data not the calculated by manufacture BC by the way.
     
  12. WildRose

    WildRose Well-Known Member

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    Well no. Actually the Berger 180 is the top end for what they make for a hunting VLD in 7mm/.284. The advertised BC is .659.

    Berger's advertised BC's also seem to be very close to what actual shooting results will produce.

    The top end of their .277's is the 150gr with a BC of .531.

    The apples to apples comparison is to compare the bullets by the same manufactuer's advertised BC's to one another.

    I'm not in any way knocking the Matrix bullets because I have zero personal experience with them but from what I've read, their advertised BC's will not match up with what's shown in the field.
     
  13. bigngreen

    bigngreen Well-Known Member

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    The new 170 gr 270 cal Berger should be getting air time right now and will be public soon, BC is .703 and is now the top 270 cal. The top 7mm Berger should show up this fall hopefully with the 195 gr bullet.

    Matrix apple for apple with the 190 7mm and the 175 270 both within a few points BC but the 270 WSM will push the same BC bullet faster.

    You can basically take a 7mm and 270 WSM and make one out perform the other just by having a fast barrel or slow barrel, the 270 is in no way lacking especially when you throw in better brass option of the shelf!
     
  14. WildRose

    WildRose Well-Known Member

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    From Hornady's loading manual 8th addition.

    270wsm 100gr max vel 3100FPS.

    7mm wsm150gr Max vel 3000fps.

    Yes it does give a slight edge to the 7WSM bullet to bullet, but then, the .270 will never push the same max weight bullets as the 7mm's period.