looking to thread my .308

Discussion in 'Gunsmithing Forum' started by rmena, Dec 30, 2011.

  1. rmena

    rmena New Member

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    I know this is probably a super dumb question and I feel bad for asking but humor me folks. can I thread my .308 to 1/2-28 and then bore out all of my ar15 flash hiders? the reason I ask is that all of the .308 fh are literally 3 times the price and I already have a bunch of ar15 fh.
     
  2. trip286

    trip286 New Member

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    If I can bore the manifold bolt holes on my motor, and build bolts for it from scratch, then I'm sure you can do what your talking about. The only question is, will the AR flash hiders hold up to it, and will they be effective?
     

  3. pagj17

    pagj17 New Member

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    Also, the 1/2 inch makes the barrel "too thin" If i'm not mistaken.
     
  4. JonM

    JonM Moderator

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    thats correct.

    OP you need to do a 5/8 threading for 308. then you can use whatever barrel attachment you want for 308's. there are adaptars to use .30 cal suppressors on 1/2 sized threads. just look up devices for 308 sized AR10 type rifles.

    you could also drill out a 1/2inch ar15 to the 5/8 308 thread size thats why they cost more. unless you know how and got the tools its going to cost more than just buying the right part for the right sized thread without having your rifle go kaboom
     
    Last edited: Dec 30, 2011
  5. rmena

    rmena New Member

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    mmm...yeah that would be too thin. is there a place that sells tempered steel that would be ok to make your own flash hiders? like a bushing that you could put in a jig and drill out and then tap? And the bigger question would be if that would even be cheaper after all is said and done? My experience has been that the fh for the .308 rifles are mostly just a bushing with a bunch of holes in it and they are asking 50-150 bucks a pop! stupid.
     
  6. trip286

    trip286 New Member

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    If your thinking of building one from scratch, practice with a high grade piece of steel pipe. Dystopian gunsmith is working on some pretty cool stuff from scratch, send him a PM and see what he thinks. He just built a pretty slick gun from scratch.
     
  7. rmena

    rmena New Member

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    will do, thanks trip286.
     
  8. JonM

    JonM Moderator

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    if your diying why not just take a standard ar15 hider of whatever type and drill it out and tap to your desired barrel threading?? its how they make the ar10 308 hiders.
     
  9. trip286

    trip286 New Member

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    Not to mention you can chop it off if you think you made it too thin.
     
  10. Sniper03

    Sniper03 Supporting Member Supporter

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    Boring out a 1/2 28 Thread! NOT! Give me a breake But get a 308 Flash Hider!:) First of all most 308s as I know them do not come standard with a 1/2 X28! So why bastardise the barrel threads should you decide to sell it in the future? :)

    03
     
  11. Robinnz

    Robinnz New Member

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    Hi , here in New Zealand .30cal and under rifles are threaded 1/2inch 20 threads as standard for supressers and flash hiders also all calibers under .30
     
  12. rmena

    rmena New Member

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    Robinnz, very interesting! Thanks for that.
     
  13. GunDoc

    GunDoc New Member

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    I have cut 1/2x28 threads for a .30 cal before but it was for testing and never fired without a strong brake attached and the threads cut really tight. 9/16x24 (mostly thinner hunting barrels) and 5/8x24 (AR and heavy barrels) are the recommended thread pattern for the .30 cal rifles. Since the military uses 5/8x24 primarily, you'll find more parts options and thread protectors available. When I thread 9/16x24 I have to make thread protectors as I haven't found any commercially made.

    The bigger brakes cost more money, but in comparison to the cost of the rifle and ammo, it's a small cost to have the correct parts installed.
     
  14. rmena

    rmena New Member

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    so lets say you wanted to make your own brakes..where could you buy a blank? do they exist?
     
  15. griffin81

    griffin81 New Member

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    I made this one on a lathe at work then milled the top and bottom down its pit on with 4 1/4 inch course set screws. I've put a lot of rounds through it and not had a problem yet. It's aircraft grade aluminum.

    image-3230064370.jpg

    image-739665616.jpg

    image-2969219724.jpg

    play the victim, be the victim
     
  16. rmena

    rmena New Member

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    that's nice! where did you get the aircraft aluminum?
     
  17. griffin81

    griffin81 New Member

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    It was a scrap from work, we use it from time to time. And I get scrap from time to time.

    play the victim, be the victim