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Posted: 10/1/2004 12:24:32 PM EDT
Stopped in the local fun shop and found a almost new, I couldn't tell it was fired, post-ban Bushmaster A2 20", with a fluted barrel. I didn't want to fork out the $699 today, being a college student w/o a lot of money so I put her on layaway. I thought it was a pretty good deal and I can't wait to go shoot that sexy beast  
Link Posted: 10/1/2004 12:25:18 PM EDT
[#1]

Quoted:
Stopped in the local fun shop and found a almost new, I couldn't tell it was fired, post-ban Bushmaster A2 20", with a fluted barrel. I didn't want to fork out the $699 today, being a college student w/o a lot of money so I put her on layaway. I thought it was a pretty good deal and I can't wait to go shoot that sexy beast  

Justin



You don't need a fluted barrel.
Link Posted: 10/1/2004 12:26:13 PM EDT
[#2]
But it already has one
Link Posted: 10/1/2004 12:30:38 PM EDT
[#3]
I am just not a fan of fluted barrels.  Makes them seem weaker in my opnion.

Good choice on the 20" though.  
Link Posted: 10/1/2004 12:32:59 PM EDT
[#4]
Either way, 699 for a like new 20" isnt all that bad, and someone paid extra to have the fluteing done. Not a  bad deal at all........
Link Posted: 10/1/2004 12:33:47 PM EDT
[#5]
Oh Yeah that is a hell of a price.
Link Posted: 10/1/2004 12:38:19 PM EDT
[#6]
Cool, post pictures when you get it...
Link Posted: 10/1/2004 12:40:37 PM EDT
[#7]
I would suggest purchasing some cavalry arms furniture for it in your fav color.

A C1 stock set, ergo grip, and oval handguards are a good, cheap upgrade. Much better fit on an average sized human IMHO.  Not gonna bust the bank as far as upgrades go either.
Link Posted: 10/1/2004 1:00:04 PM EDT
[#8]
Congratulations to you, jmarkma!!!

nothing quite like a new rifle........

wait aminute.............

Not much like a new rifle!!

Link Posted: 10/1/2004 2:15:53 PM EDT
[#9]

Quoted:
I am just not a fan of fluted barrels.  Makes them seem weaker in my opnion.

Good choice on the 20" though.  



Actualy proper fluting makes a barrel stronger!
Link Posted: 10/1/2004 2:21:26 PM EDT
[#10]

Quoted:

Quoted:
I am just not a fan of fluted barrels.  Makes them seem weaker in my opnion.

Good choice on the 20" though.  



Actualy proper fluting makes a barrel stronger!



Stronger than a similar weight barrel, the same strength as a barrel of similar dimensions.
Link Posted: 10/1/2004 2:43:37 PM EDT
[#11]
Fluting makes the barrel weaker?  Well damn wont be using mine as a Jack Handle after all
Link Posted: 10/1/2004 2:48:48 PM EDT
[#12]

Quoted:

Quoted:
Stopped in the local fun shop and found a almost new, I couldn't tell it was fired, post-ban Bushmaster A2 20", with a fluted barrel. I didn't want to fork out the $699 today, being a college student w/o a lot of money so I put her on layaway. I thought it was a pretty good deal and I can't wait to go shoot that sexy beast  

Justin



You don't need a fluted barrel.



You don't need an AR!!..........................................Or is it, "You don't need ANOTHER AR!!"  I should really listen to my wife more.
Link Posted: 10/1/2004 3:11:55 PM EDT
[#13]

Quoted:

Quoted:

Quoted:
I am just not a fan of fluted barrels.  Makes them seem weaker in my opnion.

Good choice on the 20" though.  



Actualy proper fluting makes a barrel stronger!



Stronger than a similar weight barrel, the same strength as a barrel of similar dimensions.



No will make the same barrel stonger!
Link Posted: 10/1/2004 3:31:27 PM EDT
[#14]
Congrats!!! I have a Fluted Barrel and I love mine. Mine is the Bushy 24" and is damn accurate. You'll be very pleased.

We have a BIG gun show in Lubbock Tx this weekend so I'm going to drive over and see what they have. I may come home with yet another AR Semper Fi
Link Posted: 10/1/2004 4:46:51 PM EDT
[#15]
OK let me put the fluting thing to an end. Im an engineer and during school I payed extra attention to several structural problems I recognized were similar to the barrel fluting issue even though I knew the answer to this before those problems confirmed it.  

Fluting a barrel makes it weaker than it originally was...How can you say removing material makes a straight piece of metal stronger.  

Lets say we have two 20 inch barrels.  Both weight the same amount .  One is fluted.  Its outside diameter is larger than the non fluted.  The fluted will have more surface area than the non so it will cool better.   The fluted will be stronger because more of its mass it located farther from the center of the barrel.  This increases its moment of inertia "I".  This is the easiest way to explain this.  Lets say you have two pipes 10 foot long.  one is 1 inch in diameter and the other is 1 foot.  Both weight the same, so the smaller pipe has a very thick wall or lets even say its solid.  The larger pipe has a thin wall.  If you try to spin each, the larger pipe will be the hardes to start spinning.  (It would also be the strongest as long as any bending force was applied evenly)  The larger pipe could also handle more torque too.  Thats why truck driveshafts are large and hollow instead of small and solid.

The maximum stress in any bending object happens on its outer surface.  The stess at a certain distace from the center of an object "y" can be found as below.  So if you make that distance the raduis of the barrel, y = radius.

"M" is the moment applied to a barrel.  For here we will just say thats the force of some weight hanging on the end of each of our barrels.

Now every material has a certain amount of stress it can take before it bends to where it cant go back into shape.  Think of a copper wire. You barely push on it, and it comes back.  You push a little harder, and it stays bent.  So if both barrels are of the same material, they will each bend when that stress level occurs and any part of each barrel.  So we take the equation:

Stress = (M)x(y) / I

And solve it for "M", the maximum weight each barrel can take before it bends.

M = (Stress)x(I) / (y)

lets say the stress the material can take is 1000psi.  and the radius (y) of the round barrel is 1/2 inch (.5 in).  Lets say the round barrels moment of inertia is 10 in^4 (im too lazy to actually calculate it)

1000psi x 10in^4 /  .5in = 20000 in lbs

The fluted barrel has of course the same strength, but its effective radius will be larger than the round barrel so lets say its 10% higher at .55 in.  And since it has more mass near the outside radius, its inertia will be a much higher, so lets say 20% higher at I = 12in^4

1000psi x 12in^4 / .55 in = 21818 in lbs or about 180 ft lbs of torque.  

So the fluted barrel is 1.09 times stronger than the non fluted barrel of the same weight.  

Not much difference in stregth, but youll get a fair big more surface area to cool the barrel.
Link Posted: 10/1/2004 5:19:52 PM EDT
[#16]
Jonathan,

Thanks for clearing that Fluted barrel thing up for us
Link Posted: 10/2/2004 7:23:54 AM EDT
[#17]

Quoted:
Jonathan,

Thanks for clearing that Fluted barrel thing up for us



They still seem weaker... In my opnion.
Link Posted: 10/2/2004 8:24:38 AM EDT
[#18]
but there not the same weight the fluted is lighter

and when you flute a barrel dosent it heat up faster too?
Link Posted: 10/2/2004 8:32:32 AM EDT
[#19]
Almost only counts in horseshoes and hand grenades.  
Link Posted: 10/2/2004 9:03:13 AM EDT
[#20]

Quoted:

Quoted:
Jonathan,

Thanks for clearing that Fluted barrel thing up for us



They still seem weaker... In my opnion.



They are weaker than a similar diameter, non-fluted barrel.  But they are stiffer than a similar weight, smaller diameter barrel.  However MOST OF ALL, they have much greater surface area which I believe dissipates heat better.
Link Posted: 10/2/2004 9:06:12 AM EDT
[#21]
Link Posted: 10/2/2004 9:26:53 AM EDT
[#22]
At that price sure can't go wrong with it.
Link Posted: 10/2/2004 9:35:18 AM EDT
[#23]

Quoted:

Quoted:
Jonathan,

Thanks for clearing that Fluted barrel thing up for us



They still seem weaker... In my opnion.



Next time you're having Wheaty's let me know would ya Wedge.

I'ld sure lke to piss in them for you.

Nice rifle buy the way there jmarkma and welcome to the club, sickness, disease
Link Posted: 10/2/2004 10:25:08 AM EDT
[#24]
for  $700, get the thing!!

althought i really dont like fluted, myslef, but then you anint me

remember to get lots of mags and ammo!!!!!!!
Link Posted: 10/2/2004 10:34:47 AM EDT
[#25]
great deal! i love my fluted barrel! lighter and cools quicker
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