Don't cut .308 AR barrels..!!!

Discussion in 'Gunsmithing Forum' started by ANGRYcanary, Dec 20, 2011.

  1. ANGRYcanary

    ANGRYcanary New Member

    273
    0
    0
    O.k. folks... you see, I couldn't resist. Hello..? Who's knocking at my door..?

    E P I C F A I L U R E ! ! ! :rolleyes:

    That's right Bob, tell him what he's won..!!!
    Well it was a fantastic, and I mean H U G E fireball, followed by the next round N O T being picked up from the magazine. The next sound I heard was the loudest "click" in the world. I knew exactly what had just occurred. I was not quite devastated though, at least, not till I looked and saw that there wasn't even enough timing charge to begin to eject the prior casing (still in the chamber..!). I would Highly recommend that if you choose to do this you look up the timing length from the gas port hole to the M U Z Z L E. I cut 4.75 inches off. Or just order yourself the barrel you wanted from the beginning. On a better note, all the polishing and filing and spring changing I performed on the trigger and hammer assy. have paid off, it is smoother than oil on glass, the pull is still high though, well, just over 7 pounds, according to the trigger pull scale. The "adjustments" made to the buffer tube have made it silent, but I don't think it changed the amount of "felt" recoil to my shoulder, I should probably just buy the hydraulic recoil buffer though..? Any suggestions..? The reason I'm doing all of this is just purely my own skepticism and search for personal AR-enlightenment... Before I build the Armalite...

    :cool:
     
    Last edited: Dec 20, 2011
  2. trip286

    trip286 New Member

    18,658
    1
    0
    Man, I was skeptical about that project... but I don't know enough about smithing AR's that I felt I could say anything. I'm sorry it didn't work out for you, but on the upside, Hey, you did a good job with it and it looks sharp as hell.
     

  3. danf_fl

    danf_fl Retired Supporter

    12,359
    28
    48
    Sorry about that. :(

    Now you have been introduced to the "other" side of gunsmithing. ;)
    But write it up as a lesson learned and fix it the way you want.

    That's a tough way to learn, but not as bad as some other mistakes I, er, I mean, others have done.

    (Would you have left it as it was if someone said not to cut it?)
     
  4. ANGRYcanary

    ANGRYcanary New Member

    273
    0
    0
    Thanks guys..! It's cool, well it's o.k... I'm saaaadd !!! but I'm not pissed at myself anymore...sort of a little maybe..?
    The barrel to replace it was already ordered. A Varmint thick, 20 inch, I got the threaded end for the same price that way I don't screw up trying that little trick, haha.

    trip.."Hey, you did a good job with it and it looks sharp as hell." Cool !! Thanks, longer way to go now, right..!

    danf.."That's a tough way to learn, but not as bad as some other mistakes I, er, I mean, others have done." Haha... I'm surprised the buffer tube didn't explode or something..! haha I had it apart on the coffee table and replaced those black rubber discs with some very squishy aircraft rubber.

    (Would you have left it as it was if someone said not to cut it?) Hahaha, admittedly... Um, hmm, no. I know, I know. But I had to try it...
     
    Last edited: Dec 20, 2011
  5. fmj

    fmj New Member

    3,459
    0
    0
    not sure WHY one would want to cut a barrel on a rifle in the first place. Longer barrel = more energy and better distance accuracy.:confused:
     
  6. ANGRYcanary

    ANGRYcanary New Member

    273
    0
    0
    Longer barrels don't necessarily equate to better accuracy, thicker barrels do, because thicker barrels are less prone to the pulses produced by firing of the weapon. Longer barrels assure better burn times for the powder charge (thus the reason for the huge fireball). can we not have this discussion again, it's not why I posted this. This is a post to give an example that the gas port needs to have correct timing length to the muzzle. I just happen to like short barrels. Thanks for your opinion though.
     
    Last edited: Dec 21, 2011
  7. Catfish

    Catfish New Member

    514
    0
    0
    The AR is gas operated and by cutting off that much of the barrel you are not maintaining enough presure to cycle the action.
     
  8. ANGRYcanary

    ANGRYcanary New Member

    273
    0
    0
    Did you even look at the beginning of this post...

    Yeah, I know how an AR system works. That's why I put up a post 10 days ago to find out if leaving 3.25 inches between the gas block and muzzle, would still give the barrel enough timing between the gas block and the muzzle to keep the pressure high enough. When no one answered with a solid definitive yes, no, here's a chart to look look at or even a link, I ordered a new 20 inch barrel, and cut the old one off. The result, I wanted for myself, had to be found out and authenticated by myself. I was just trying to post results so in the future people would be able to say, FIND A CHART, but if you cut down a 20" to 16", it had better have a mid length gas port. Don't worry folks, it won't happen again. A better experiment would have been for me to take off an inch at a time, and document it on video. Then get a patent, on the video, then post it, then you could not watch the video, and tell me after it's posted that it won't work. Yeah, that's what I'll do next time.
     
    Last edited: Dec 21, 2011
  9. orangello

    orangello New Member

    19,156
    0
    0
    They really let you have an AR, much less in .308 in sillinois? Are you friends with the governor or something?
     
  10. ANGRYcanary

    ANGRYcanary New Member

    273
    0
    0
    I know right... Thank God for small miracles...
     
  11. trip286

    trip286 New Member

    18,658
    1
    0
    Canary, I won't knock your project. I for one had no idea if it would work for sure. It was a learning experience, and you did good work, and now your correcting a mistake, big deal. Don't worry about the people who want to come in after the game is already played and tell you how to overhaul the playbook.
     
  12. jpattersonnh

    jpattersonnh Active Member

    5,360
    3
    38
    That sucks. At least you have an erector set rifle!!!
     
  13. MidnightExpress

    MidnightExpress New Member

    251
    0
    0
    He may have gotten tired of you trying to be cleaver/humorous in the beginning. I nearly gave up on this myself. Good thing no innocent by-standers were injured.
     
  14. ANGRYcanary

    ANGRYcanary New Member

    273
    0
    0
    HAHAHA Thanks guys... I didn't write that mad, just sort of... tired of other life stuff (x-wife, custody battle) I was tryin to keep my cool but still be um... better understood..? You guys know I'm a smartass, maybe even "kid-like" at times.

    Thanks trip..! Good playbook ref. That I still understand..! HAHHA:D
    Hey patterson, need a short barrel for a new project, It's real cheap... ;) just call me honest CANARY.
    Midnight... Thanks... I should save it for the end of the post...
     
  15. HOSSFLY

    HOSSFLY New Member

    6,932
    0
    0
    Hey- It was a learning exsperience :rolleyes:
     
  16. ANGRYcanary

    ANGRYcanary New Member

    273
    0
    0
    Haha.. Hey Hoss, You should've seen that fireball !!
    SHEET !!
     
  17. pagj17

    pagj17 New Member

    2,455
    0
    0
    You could open up the gas port... that would increase pressure delievered to the bolt.
     
  18. neilage66

    neilage66 New Member

    630
    0
    0
    You might try a muzzle device like the Noveske KX3?
    [​IMG]
    There is also a PWS unit like this.
    [​IMG]

    They were originally designed to increase gas pressure on SBR's in order that the action would fully cycle.
    Of course this only works if you have a threaded muzzle 5/8-24 I believe.
    Just ideas...
    Good luck with the *new* barrel you have coming.

    ETA: I am repeating myself from another thread regarding AR10's so please forgive me for the Noveske whoring. ;)
     
    Last edited: Dec 21, 2011
  19. Jpyle

    Jpyle New Member

    4,828
    0
    0
    Not a bad thought at all. Other option is to cut the barrel below the gas port, rethread it and put a muzzle break and extension to get back to 16" (not sure how far your cut it) then tap a new gas port at the midlength point and change the gas system to midlength...should work like a dream.
     
  20. MidnightExpress

    MidnightExpress New Member

    251
    0
    0
    Yeah, or in the middle. :D Honestly yours wasn't bad. I've read some for like 10 minutes and I'm still waiting for the point. Read some books like that too. Waiting for something to happen, and they're telling me what shade of blue the sky is and why it reminds them of some childhood memory no one gives two sh**s about. Your post was nothing like those.