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22-250 straight pull SKS rebarrel

Discussion in 'Gunsmithing and Repairs' started by Whimis, Aug 12, 2019.

  1. Whimis

    Whimis Member

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    Hello all, I've been kicking around the idea of taking an SKS and rebarreling it to 22-250, adding a swept back bolt handle, making a new stock, losing the gas system and running it as a straight pull.

    I know that I'd need a new barrel, trigger job, solid side mounted scope rail, and to open up the bolt face from .439((?)(correct me if I'm wrong 7.62x39 bolt face) to .473 for the 22-250.

    The only thing I have holding me back from starting my project is I don't know if the SKS action could handle the 22-250 pressure (7.62x39 = 45k psi according to Wikipedia and 22-250 = 65k psi according to Wikipedia)

    Would the action be able to handle the 22-250?

    This will be my winter project as long as it seems safe to do so.

    My thought is that it would make a very handy, and quick shooting varmint rifle.

    Hope to hear everyone's thoughts, thanks!
     
  2. BBBBill

    BBBBill Member

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    I would not chance it without having some serious calculations done buy someone more skilled than I am first. The SKS was engineered around the 7.62x39 round and does not seem to have any excess material available to resist the 44% higher pressures. I say pressure, but it is as much breech thrust load as pressure to be concerned with. A quick and dirty calculation shows the 7.62x39 has around 6300 pounds of breech thrust while the 22-250 has around 10,200 pounds of breech thrust, about 62% higher. I see two potential failure points - the locking shoulder and, if it is a pressed and pinned barrel, the barrel pin. Actually more, but those two would probably be in the mix if not the first. Kinda rough to be digging a bolt out of your forehead after watching your barrel follow the round down range. And don't forget that the Communists have never been known for considering the health and welfare of individuals in anything that they do. Individuals are as disposable as any other item to them. I am pretty sure that they did not use the best alloys available to make their weapons.

    Additionally, I don't think the 22-250 will fit the action due to its greater length.
     
    Last edited: Aug 13, 2019
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  3. 25-20 WCF

    25-20 WCF Member

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  4. Whimis

    Whimis Member

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    BBBBill- I'd be starting with a threaded barrel SKS, I'd look into other common varmint calibers that would be more suited to the action but my concern there is ammo availability and if it has a smaller bolt face

    25-20 WCF- I had seen that article and it was what got me started on this path, my original plan was to rebarrel a Mosin Nagant to 22-250 but I decided that the difficulties with reworking the boltface, and the price of the donor rifle I'd need I scrapped the idea
     
  5. boom boom
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    boom boom Contributing Member

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    If you want a straight pull action which fires a modern pressure level cartridge like the 22-250, one of the cheaper ways to do it via something like an AR 10 with the gas system shut off if you use an adjustable gas plug or simply eliminated it during the build. You can get both the side charging receiver and the AR-10 has been chambered for the 22-250 by commercial vendors so you are probably good on pressure levels. The bolt design also allows fairly simple changes for cartridges although I do not know if the variety of different bolts for its little brother AR15 rifle exists for the AR 10.

    It might still be inferior to a Remington 700 model or a Ruger American bolt actions for 22-250 in accuracy and operation and might end up being a kludge unless you have pretty good fabricating skills. Another alternative is building a 22-250 bolt action with a custom barrel and stock around an existing howa, savage, remington action which all use modern metallurgy and are strong enough with easy parts accessibility to make the conversions.

    Unless you get the practically the last generation of military surplus bolt actions, such as the 03-A3 etc, most were rated for well under the max pressure levels of the 22-250 and the overall expense would once again be greater than a bolt action in the first place.

    Select fire battle rifle actions were not really designed to ease future sporterization and the rifle designs were built around the issue cartridges rather than vice versa. Thus the functioning, parts, etc. were based on reliable operation first and then easy machining and assembly, maintenance ease, cost, etc. and not necessarily to maximize the strength of the receiver, bolt, or other parts. The quality of these parts are often "good enough for government work" which means the military application and cartridge it was designed to fire plus the need to function in all sorts of awful conditions. All of those tolerances necessary to meet government standards can make it difficult to make an varmint quality rifle in accuracy and function from a semi-auto military rifle design.

    Now, because of restrictive laws in Europe, you can find quite a few projects where they have converted what should be select fire military rifles into manual straight pulls. You might get a better idea of what could be achieved from those folks but here it would be a one-off type project that someone with the tools, knowledge, and time might to some scrap parts. There are simply better options in varminting available through bolt actions for most folks to make the project that appealing here.
     
  6. Whimis

    Whimis Member

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    Boom Boom- the AR platform wouldn't work for my purpose as it is a restricted firearm and can only be shot on a range here in Canada

    I wanted to stay away from the bolt actions so that I could have something different and faster to fire

    I know that there a better actions to build on that would probably peak more interest, but this is more of a just for me rifle, it will never be worth what I'd put into it in $$ but if it serves the purpose I'm building it for I'd consider it money well spent

    My initial thought on using the SKS action was the cost of the donor rifle was cheap.

    Any other straight pull rifles or semi auto rifles that would make a better donor for this project? Or a more suitable cartridge for the SKS action?
     
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  7. Jim Watson

    Jim Watson Member

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    .22 PPC
    Which is .220 Russian Improved. Which is .22 x 7.62x39 necked down.
    Same head diameter, probably manageable in magazine.
    Quickload to what the SKS action can handle.
     
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  8. #1buck

    #1buck Member

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  9. Whimis

    Whimis Member

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    Jim Watson- while the .22ppc looks to be an effective cartridge my issue with it is ammo availability since I'm not reloading :/

    #1buck- that actually looks pretty cool haha, if this project doesn't get off the ground for me I might need to look into that. Would it be practical- nope, would it be a functional interesting gun- absolutely
     
  10. LoonWulf
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    LoonWulf Contributing Member

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    this is what I'd go with as well.
    The .22-250 generates more pressure, significantly more, than the X39. Also even at the same pressure it would develop more bolt thrust because of the larger case head.
    couple those two things and your asking for trouble.
    You might even try going to a 224 valk, or .22 nosler to reduce bolt thrust while still maintaining a larger than .223 case.
    Not sure if the mag could be made to work, and reducing the bolt face and the extractor work would be a pain, but you'd be able to run higher pressure with less bolt thrust.
     
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  11. Jim Watson

    Jim Watson Member

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    Here is a Wiki list of straight pull rifles.
    https://en.wikipedia.org/wiki/List_of_straight_pull_rifles

    I think you could just as well buy a Blaser or other sporting rifle as you could convert some military surplus, unless you are a proficient machinist and knowledgeable gunsmith. And if you were, you wouldn't be asking us.
     
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  12. PRD1

    PRD1 Member

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    All technical considerations aside, I say, if you feel like doing it, go ahead! You'll definitely learn a great deal in the process, and others may profit (one way or another) from your experience. Please make a video record of your test firing. If it doesn't work out as you hope, I'll see that you are given full credit in nominating you for the Darwin Awards...

    PRD1 - mhb - MIke
     
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  13. boom boom
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    boom boom Contributing Member

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    Jim Watson posted probably the best solution using an SKS but I would not know if the .22 PPC is a suitable varmint cartridge.

    As far as milsurps go, probably the best straight pull would be the Swiss 1911/k31 aka Schmidt Rubins but you would have to have a custom barrel made and fit the cartridge used to the straight pull action and magazine and probably most of the wildcats would require handloading. The action though is strong and made with excellent steel and craftsmanship.

    As far as speed, consider one of the Lee Enfields which are more available and I believe that a conversion to .223 has been done perhaps with some of those Ishapore receivers used for 7.62 ammo or the No. 4 receiver if I remember correctly.

    The Lee Enfield's bolt can be worked pretty fast and apart from something like a blaser etc., I would argue that the Lee Enfield can be operated at least as fast as the Swiss Schmidt Rubin with practice and the mag capacity is larger whether that matters to you or not.
     
  14. Whimis

    Whimis Member

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    Seems as though I should probably just scrap the idea for safety reasons.

    Thanks everyone for your replies!
     
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  15. Carl N. Brown

    Carl N. Brown Member

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    SKS actions are a bit much oversized for the 7.62x39 cartridge so they have a decent track record with the 7.62x39 cartridge.
    Variations in quality of Chinese materials and standards of manufacture over the years would persuade me to not wildcat some random SKS.
    I still remember tales of Chinese SKS rifles assembled with press-and-pin receivers and threaded barrels pinned to fit.
     
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