FN AR heavy or light barrel?

Discussion in 'Auto & Semi-Auto Discussion' started by Kent E, Jan 15, 2009.

  1. Kent E

    Kent E New Member

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    I'm considering an FN AR. (yes, I know it's an ugly gun)

    But here's the dilemma. Which barrel to go with? There is a light and a heavy version. Here is a link if you want to look at it:
    http://www.fnhusa.com/le/products/firearms/family.asp?fid=FNF049&gid=FNG022

    The most realistic use will be target practice. I would like to learn to shoot long distance but have little experience. What are the advantages of the heavy barrel?

    thanks for your input.
     
  2. matt g

    matt g New Member Supporter

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    Buy one of each. Supposedly, they're hot swappable.
     

  3. Kent E

    Kent E New Member

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    unfortunately, I won't be buying two.
     
  4. Txhillbilly

    Txhillbilly Active Member

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    I always look at it this way. If it is going to be a gun that I mainly use for target/bench use,I will get the heavy barrel.The heavy barreled gun will be more accurate than the lighter one. Now if I was going to be walking miles & miles on a hunting trip I might want to get the lighter one. But I have toted my Savage 110FLP around on an elk hunt in Montana a couple times and it is one heavy beast,and it didn't bother me that much.
     
  5. Scud

    Scud New Member

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    I would buy the light barrel. The price and availability of maks would turn me away however. Have you considered a DSArms FN FAL? The mags will cost you much less. I would also look into an AR 10 platform -- Rock River Arms makes an AR 10 type that takes the FAL mags.
     
  6. Kent E

    Kent E New Member

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    I'm not concerned with the price of mags, this gun is what I'm looking for.
     
  7. Dillinger

    Dillinger New Member

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    Kent - If you have your heart set on the weapon, then your decision is made.

    However, I have to ask what is your goal?

    Do you want a semi auto, mid to "long" range shooter?

    Because a .308 round is really only good to about 600-650 yards and with a 20" barrel, you are not going to get MOA accuracy out of a semi auto platform, with that configuration, at that range.

    What is your definition of "learn to shoot long distance"?

    JD
     
  8. Kent E

    Kent E New Member

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    That's a great question. To me 600 is a long distance. Some of the articles I've read puts the FN AR accuracy to around .4 accuracy. That's better than I could do.

    I'm mostly interested in what advantages a heavy barrel gives in real world conditions. Say your shooting with some friends, will the heavier weight barrel mean less waiting between shots? Will it make that much of a difference?

    Has anyone shot the same gun in heavy and light barrel and noticed a real accuracy difference?
     
  9. matt g

    matt g New Member Supporter

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    Heavy barrels help by providing "at rest" inertia. This mildly lessens recoil and damps barrel whip/harmonics.
     
  10. Dillinger

    Dillinger New Member

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    Okay, first off, whoever is telling you that a production built rifle, with a 20" barrel in .308 caliber, will shoot .4 MOA at 600 YARDS has ONE HELL of rifle in his/her hands, and is an AWESOME shooter.

    I am not saying it's impossible to create such a thing, but in a production environment, I would find it EXTREMELY hard to believe that this is a common occurence.

    Shooting 600 yards is a LONG ways. 6 football fields is easy to throw out there, but actually stand on a football field and look at the other endzone, that's 100 yards, short of the end zones.

    .4 MOA is a three shot group ( NOTE: we do a 5 shot group at our shop after a fouling shot ) that measures, what, like 2.4 inches?!?! That is impressive by anyone's standards, but with a production semi-auto with a 20" barrel and factory ammo?

    I am skeptical to say the least, but I have been wrong before and will be again, I am sure....

    As for your question concerning the thin versus thick barrel.

    A thick barrel will ALWAYS beat a thin barrel in multiple shot groups with all things being equal. The reason is many:

    Barrel Harmonics
    Heat Dissipation
    Outside Influences ( stock contact, sling tension, barrel "whip", etc. )

    The greater the force ( the round pressure in question ) is on the density of the material in question ( the thickness of the barrel ) is always going to be greater on a thin barrel versus a thick barrel.

    If you don't have to pack it for hundreds of miles - a thick barrel is ALWAYS the correct choice.

    JD
     
  11. Kent E

    Kent E New Member

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    Hey Dillinger, Thanks I'll go with the heavy barrel and will use a lighter bolt gun for wandering.

    As far as accuracy, I'm just going off of what others report. I don't have one yet but am hoping to.

    Rifle Shooter magazine Jan/Feb on page 30 had a 5 shot .45 MOA

    Here is a guy who just did a range test: FN Forum.NET PS90 FS2000 FN SCAR FiveseveN 5.7x28mm FN Forum.NET :: View topic - 5/8" MOA verified today at range!!!!

    The gunblast guy fired three bullets into the same hole at 50 yards. FNH 7.62x51 (.308) FNAR Semi-Auto Rifle
     
  12. Dillinger

    Dillinger New Member

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    Kent - After reading the links I have two thoughts....

    1) 50 Yards?!?!? My Sister can shoot at 50 yards - with ANY long gun, that is not a measure of true "accuracy". I frequently shoot 50 yards outdoors with my 1911's at a 10 steel "gong" and ring it out....

    2) That guy in the review is shooting handloads. I didn't read enough to see if he was shooting fire formed brass, but still, it's easy to handload better ammo than you can buy "off the shelf".

    I don't know if this production rifle can shoot, or not, so you are kind of venturing into dark territory.

    I can tell you this, using a 20" barrel to shoot 50 yards is like nailing a porn star - it's a sure thing & anyone can do it. :rolleyes:

    Good luck with whatever you decide, but I would definitely price shop the FN versus a "Standard" .308 AR.

    JD
     
  13. XMPnPA

    XMPnPA New Member

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    Good Answer

    Dillinger:
    Way to lay it all out there. Good post I, I fully agree...... not much else to add.
     
  14. MXFun86

    MXFun86 New Member

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    I personally went with the heavy barrel. My AR has a 16" heavy, and also a 24" bull barrel. It (bull barrel) gives me about a 1-1.5" group at 200yds. My 16" has similar results at 100 yds. I don't have the oppurtunity to shoot any further. But I swear by the heavy weights.
     
  15. Dillinger

    Dillinger New Member

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    Kent - That is a pretty good range report I have to agree. For a factory gun, that is a nice final 3 shot group.

    A couple of things though - The guy was handloading for the rifle and he did say that was the best group after he got "into the swing of things" - I don't know if that means getting on paper with his rifle, or adjusting to the wind, or what.

    Just to keep in perspective. ;)

    Still, that is some impressive shooting for a final result.

    JD
     
  16. Kent E

    Kent E New Member

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    I'll agree with that.

    There's just a possibility that FN is on to something here. Too bad they could ad some styling to go with that accuracy.
     
  17. Dillinger

    Dillinger New Member

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    Agreed. She isn't a beauty queen, but she seems built for stout. If the weapon can prove to cycle with different types of ammo, for a SHTF scenario, you might be on to a winner there.... Never hurts to have a good .308 in the safe. :D

    JD
     
  18. Kent E

    Kent E New Member

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    There's the "black rifle"

    Now also an "ugly rifle"
     
  19. matt g

    matt g New Member Supporter

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    I dunno', I actually think they look much better than the AR. ARs are butt-ugly to me., they just look like toys.