Firearm & Gun Forum -

Firearm & Gun Forum - (
-   Auto & Semi-Auto Discussion (
-   -   FN AR heavy or light barrel? (

Kent E 01-15-2009 08:14 PM

FN AR heavy or light barrel?
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:

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.

matt g 01-15-2009 08:20 PM

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

Kent E 01-15-2009 08:36 PM

unfortunately, I won't be buying two.

Txhillbilly 01-15-2009 08:44 PM

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.

Scud 01-16-2009 11:39 PM

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.

Kent E 01-16-2009 11:48 PM

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

Dillinger 01-16-2009 11:50 PM

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"?


Kent E 01-17-2009 12:52 AM

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?

matt g 01-17-2009 01:05 AM

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

Dillinger 01-17-2009 01:14 AM

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.


All times are GMT. The time now is 10:46 AM.

Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.