7mm stw build in progress

Discussion in '7mm STW' started by Lefty7mmstw, May 23, 2015.

  1. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    Well, I took my 7mm stw to a local 'smith to get the headspace reset since it was eating up brass rather quickly even with mild loads. It turns out the barrel shank threads were cut so undersized that the barrel is loose until the last turn or so before it snugs up to the action. The headspace was about .012" longer than I wanted too, so it was the excessive headspace eating up brass.
    The store I bought it from has come up with enough $$ to finance the barrel. Not a full repair by any means but I'm going to take the rifle to action and build it over.

    I am :

    - going with a longer barrel than the 24" that was on her... not sure yet how long and fat this barrel will be but I don't want a 10# barrel so there are limits-- also it will be 8 or 9" twist... not 10" like the current bbl.... I'd also like to keep the finished weight of the rifle under 12#

    - replacing the modded walker trigger that was on it with another-- ideas??

    - replacing the recoil lug with an aftermarket

    - keeping the m70 type safety... I wasn't sure at first but I like it---

    - replacing the stock-- likely pillar bedded/skim bedded Boyds laminate to replace the bdl stock

    - leaving the stock mag. length.. I have 400 rounds loaded to 3.650" oal and have never seen jump make a hill of beans worth of difference so .150" jump it is...


    I am not sure if the new incarnation of this rifle will get a brake

    I am not sure of using the ratchet or 5r type rifling-- Ideas??

    as far as the reamer I am thinking either standard or tight chamber standard neck... pros and cons of this please??
     
  2. WapitiBob

    WapitiBob Well-Known Member

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    I see my groups open up with a .005 change in jump. I wouldn't have believed it but I can see it on my targets with these 140 TSX's. When I redo my barrel I'm going with a tighter neck. My brass is .311 loaded and .318 fired. I think I would like to be .314-.315 fired.
     
  3. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    I'll work with the bullet jump while working up the load...

    I am looking for a good trigger without a safety for the m700 and a 8 twist 26" or longer finished 7mm barrel.... preferably ratchet, 5r, 4groove, etc. with a middle contour between "sporter" and bull/ varmint.... If anyone has a leads on these I'd be all ears...
     
  4. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    barrel and recoil lug are on order and I've got a Boyds stock on the way also that I may use...

    28" 8" twist shilen match stainless # 5 contour
    ptg lug .250"
    boyds prairie hunter pepper grey
     
  5. eshorebwhntr

    eshorebwhntr Well-Known Member

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    I've got a .313 neck on mine and really like it. Finished round is about .311 or so. Never had a problem with feeding at all.

    For reference, I've got a R700, 28" Krieger #8 contour fluted, with a GBP stock, mark 4 6.5-20 and it weighs 12lbs 12oz.

    I think you're dead on with a #5 contour. It's what I'm going with when this barrel is toast. If you're running 140's through that barrel it will be super fast and the jackets might not like it too much with all that twist (unless you're shooting barnes bullets)

    If its me, I'd put a Darrell Holland radial baffle brake on it and have a thread protector made for it. That way you can have it both ways.
     
  6. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    thanks on the weight info... my brother is building a 280ai @ present and using a #5 contour (brux 9" twist I think) also... I was thinking of going a bit thinner but this round likes a bit of "meat" in the barrel and the last barrel was crappy/flaky at a lighter contour...

    My brother has also mentioned the thread protector/ radial brake idea.... I'm not as scared of radial brakes as some as I usually shoot from sitting... there's a good bit of free space to the ground and dirt kick up shouldn't be an issue... I am trying to conserve $$ a bit though so this may be done later...
    as to the bullet/ twist issue... I'm using N.A.B.'s at present (they'll take a lot more than some bullets before issues) but who knows if the new barrel will even like them... I will do load development to see that I guess.

    The scope also stays for now... the 6x24 elite 4000 has been a real winner for me.... I'll eventually get something with a zero stop though... maybe after I win the lottery <G>
    My "smith also wants to take a good look at the trigger before we decide on replacing it... why toss more $$ in if the existing trigger will do...
     
  7. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    the barrel and recoil lug are here... the stock went to Nebraska for some reason and will be in this week....
     
  8. eshorebwhntr

    eshorebwhntr Well-Known Member

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    the name of the brake is a little misleading. it is a 100% side discharge brake. he also makes a "quick discharge" brake which is a side discharge with 3 holes in the top. I like both and have had good luck with both. It has been mentioned by a guy on here that the unbalanced holes in the top put a lot of flex in the barrel from that gas though.
     
  9. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    I picked up a Timney trigger the other day in Bowman. They are built so the safety can come off without compromising the safety.
    I am taking my box of parts to my 'smith today.
     
  10. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    well, got everything to my 'smith. He mentioned the barrel is marked select match.... guess I got a deal.... two weeks build time and we'll see how she shoots...
     
  11. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    Update; the lathe work is done. I will be able to pick the rifle up next week after the recoil lug is blued, the bolt is back together, and a bit of final polishing is done. I'll then fit the new stock to the barreled action.

    As to the other barrel being sloppy; The previous barrel was likely ordered standard rem 700 threads and my receiver was trued in the neighborhood of .030" over at some time in its life. I could likely use the old barrel on another receiver if I saw fit.

    I should have the rifle shooting next Saturday. A few break in shots and on to groups.
     
  12. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    The build is done and she shoots!!!

    .98" group at 200 with the 180 sierra hpbt at 2900 fps for the first group out of the barrel after sight in!!!
    It also shoots the 140 nos bt/ab load with 82 rl25 to 3350 fps and .54 moa at 200!!! Looking forward to wringing out this rifle a bit more....

    I will burn some h50bmg and rl50 in her with 180's to see if I can get the speed up while maintaining accuracy with the 180's; they lost accuracy as the pressures came up, eventually loosening to 1.5 moa at 3150 fps.

    We had to ditch the m70 style safety. I also went with an old style bedding and cut the stock out till I had enough relief for the barrel to go in, then put a felt pad under the fore end of the stock for a bit of pressure.

    We are still waiting on a remmy bolt shroud and I've got to get my wife to get her paint brush out with a bit of one of the gun coatings to letter the barrel. I'm not a fan of hand stamped barrels and having a degreed artist in the family opens up a different avenue on the barrel marking for me so I'm taking it.
     
  13. Black67

    Black67 Well-Known Member

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    Pics or its not true :D

    That sounds like a good shooting gun that you have, and its not even broken in yet. Glad to here that everything has come out as good as you wanted.

    Have you tried any other bullets in it, I wonder if it would like the long Barnes LRX 168 gr jobs.
     
  14. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    No pics until I get the PTG firing pin/shroud in... She is still wearing the win style shroud without the wing safety in 'till my Midway order shows up. I'd like to get the barrel lettering done too, but that's another story...

    As to pills, I also have some 180 hybrids coming in... I think that the 168 Barnes and 195 Berger are were this barrel eventually needs to go to make use of the 8" twist. The Berger isn't out yet though and I'm not sure how well the Barnes will open up on a deer at 700 yards and change.....