338 Sin

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by sinarms, Jan 16, 2011.

  1. sinarms

    sinarms Well-Known Member

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    I have been working on this project for a while now and it was designed to be a long range hunting round just like the 338 rum and 338 edge. The purpose was to get as close to 338 Rum performance and still work in a std length long action. I make a ton of barrels for Savage rifles and have been producing quite a few 338 edges. My customers ask me how to make a Savage a repeater with an edge and I have to tell them it would take a lot of more, lots of money and still limit the oal of the round. So I went to work designing the 338 Sin, what it is based off is the 300 rum/338 Rum case. The case is shorten to std 338 win mag length and then the case is blown out and changed to a 40 degree shoulder. I am with in 6grs of the 338 rum for capacity. I am awaiting my reamers to show up but my HS gauge came on friday so I thought I would share a little. This is designed to work with Savage/Howa/Vanguard/ect. all you need is a std magnum rifle and you can swap the barrel out and have a long range target/hunting rifle with out spending tons of money on custom mag box or stocks. Let me know what you think. I will post pics of the test rifle when the reamers show up. Thanks
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  2. RH300UM

    RH300UM Well-Known Member

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    This might be a stupid question, given all that you have put into this, why not use a 338 Norma Mag case? Basiclly the numbers as you have now.
     

  3. sinarms

    sinarms Well-Known Member

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    there is more support for the Rum case and the Rum case uses the std mag bolt head and not the lapua bolt head
     
  4. bigngreen

    bigngreen Well-Known Member

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    Dig it!! I was playing with a 338 Edge and a 338 Norma the other night in a Vanguard and a Savage and the Edge just did not look like it was a simple repeater situation without compromise. The Norma on the other hand was perfection and with the bullet seated in the right place but it will also need some mod to work, the Edge looked like the bullet was wearing a turtle neck it was seated so deep.

    Will you be selling the reamer and gauge?
     
  5. AZShooter

    AZShooter Well-Known Member

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    I like the concept. I have been pondering the same problem. The closest to what you have designed is the 338/375 Ruger or the 338 Dakota but yours will have more velocity.

    I am VERY interested in it. How do you go about forming the brass?
     
  6. geargrinder

    geargrinder Well-Known Member

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    Sinarms has built me two 338 Edge barrels and I couldn't be happier. Devin is great to work with.

    I've been following this pretty closely over on Savageshooters.

    He's going to make the dies as well. So, starting with a 300RUM, all you'd have to do is FL size it in the die. That should make the 40 degree shoulder, there may be a little to fireform in the case wall, but it shouldn't be much.

    All that would be left is to trim to length and turn the neck if it's too thick.

    I'm going to use 338 RUM brass in my 338 SIN. :D
     
  7. sinarms

    sinarms Well-Known Member

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    I will be offering die's cut from blanks, probably just the body so you can add what type of expander and seater you want. I will probably carry the gauges and maybe a reamer. I will mainly concentrate on offering barrels for people that want to install them. I might put together a few rifles here and there ready to go.

    Forming the brass will be just like any ackley cartridge but I might mess around with making a hydro forming die and see how easy that works. I might offer brass ready to load but my time is already limited so I dont know how I would be able to offer that but who knows.
     
  8. bigngreen

    bigngreen Well-Known Member

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    I went over to SavageShooters and found the thread, I think this may just be the ticket for a no brainer, roll on and play 338 with some capacity! Kinda makes me wish I didn't have a 338 RUM reamer ready to rumble for a Savage build. Kudo's on also offering a die set up with your new chambering from the start, I think it sucks to have to piece together dies for a new rifle!
    Good luck with it and can't wait to see how it performs!!
     
    Last edited: Jan 16, 2011
  9. sinarms

    sinarms Well-Known Member

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    I ordered a set of RCBS 338 win mag dies for the guts and 338 rum brass just so I have less to cut off when formed.
     
  10. sinarms

    sinarms Well-Known Member

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    forgot to add, there will be a 7mm and a 30cal version of the Sin too, and they will probably be developed in that order.
     
  11. MSU Marksman

    MSU Marksman Well-Known Member

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    This certainly has peaked my interest. Have you ran any data through quick load to see what type of performance you can expect? Will you be able to seat a 285 Hornady long and still feed from the magazine with it?
     
  12. angus-5024

    angus-5024 Well-Known Member

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    Very cool concept. I have been contemplating re-barreling my .338 RUM to a Norma, but this sounds even better. Keep up the good work!
     
  13. sinarms

    sinarms Well-Known Member

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    I am waiting for my quickload to install to run the data but the cartridge will mainly be used with the 200-250gr bullets but we will run 300gr bullets too so I would assume that the 285gr will be able to be used too. I am really wanting the 338 wildcat bullets but those are pretty rare right now.
     
  14. Firecat

    Firecat Well-Known Member

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    Sounds pretty interesting. I have been pondering a savage build and a 338. Sounds like you may have the answer.