Hot barrel

Discussion in 'General Rifle Discussion' started by bushmaster74, Jun 8, 2014.

  1. bushmaster74

    bushmaster74 New Member

    Hi y'all I just acquired a new ar in the collection. A cmmg 4 sa with a 18" barrel. Shot it today a couple of shots. Then rapid fired 30 rounds of cheaper surplus ammo just to see if she'd jam or anything. Did fine but noticed barrel was very hot. Hotter than I've noticed my other ars got. I don't usually rapid fire any way but was just testing. Hot like couldn't hold hand on barrel at all. Do ya think there's a problem or am I looking too far into it. Also was thinking on changing to a longer barrel. Any suggestions on length ? Was thinking on 24" but wondering if anyone had better suggestions

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  2. c3shooter

    c3shooter Administrator Staff Member

    An AR is an air cooled nitrate burning engine. Rapid fire with ANY AR will heat the barrel quickly- it has not had time to radiate heat to the air around it. A heavy barrel will heat more slowly due to the thermal mass of the barrel.

    This is why the military list different rates of fire for short term, mid term, long term shooting. You think YOURS got hot- you should see an M16 after dumping a half dozen mags on full auto!

    Not unique to the AR family of rifles- that is why military rifles for over 100 years have a handguard above the barrel- so you can grab a hot rifle without branding yourself.

  3. bushmaster74

    bushmaster74 New Member

    Thank you. That eased my mind slot. Any opinions on barrel length? Looking for longer range and more precision

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  4. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

    Barrel length has little to do with accuracy. An accurate barrel is an accurate barrel regardless of length. Length vs thickness can affect barrel harmonics. A shorter, thicker barrel will have less "whip" and is potentially more accurate. Many refer to these barrels as "bull" barrels.

    A 16", well rifled barrel that is 2" in diameter will have almost zero "whip". A 20" minimum diameter barrel (pencil barrel) will have decided "whip", but not necessarily inaccurate.

    Chrome lined barrels tend to be less accurate than chromed. 5r rifling is renounded for accuracy. For accurate shooting in an AR, look for a Chrome Moly barrel with cut rifling from a good name maker. Even then it depends on the ammo.
  5. Franklin1995

    Franklin1995 New Member


    I think you're okay ;) It catches fire about 4 minutes in
  6. Axxe55

    Axxe55 The Apocalypse Is Coming.....

    i can dump a 30 round mag quick enough to get the barrel dang near hot enough to light a cigarette!:D

    very seldom to i shoot my AR that quickly, but do on occasion just for fun.

    yes, they get very hot. it's normal.
  7. SSGN_Doc

    SSGN_Doc Well-Known Member

    Unless you are handloading and using slow burning powders, a 24" is hard to take advantage of in .223/5.56. 20" is long enough to use on my match AR for military matches out to 600 yds.
  8. therewolf

    therewolf New Member

    You may be a candidate for a 20" or 22"

    bull barrel. I love mine.
  9. 7point62

    7point62 Lifetime Supporting Member Lifetime Supporter

    M60 barrels could get so hot they'd turn ash-white. That's why you had a spare barrel and an asbestos glove. But it didn't hurt the gun.
  10. Hookeye

    Hookeye Active Member

    I'd be more concerned about the wallet burn than the barrel burn.
    Cheap and easy to rebarrel an AR.
    Blaze away and enjoy it.
  11. bushmaster74

    bushmaster74 New Member

    When buying a barrel. Do you usually get gas block and tube with it? Where do they decide where the gas block goes? The barrel I have now has the fixed front sight/ gas block Will I need to shop for a new hand guard also ?

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  12. Salvo

    Salvo New Member

    This is what happens to your barrel when it gets too hot.

    Click image to see it larger.

    It all depends upon what is more important to you... Accuracy - or burning up ammo as fast as you can for fun.

    It's your gun, your ammo, your decision.

    I'm an accuracy freak who waits a minute or so between shots - but that's just me. - To each his own.

    Kind regards,