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Posted: 11/1/2004 12:49:15 PM EST
Im not really sure how it works despite myself owning a "freefloated" AR. Whats the science behind it?

so the handguard doesnt touch the barrel, whats the big deal ehh?
Link Posted: 11/1/2004 12:52:18 PM EST
[Last Edit: 11/1/2004 12:52:48 PM EST by JHP]
simple version....things that touch the barrel can cause it to be less accurate

Link Posted: 11/1/2004 12:53:04 PM EST

Originally Posted By gaspain:
Im not really sure how it works despite myself owning a "freefloated" AR. Whats the science behind it?

so the handguard doesnt touch the barrel, whats the big deal ehh?



The handguard exerts a force on the barrel. Any force on the barrel can affect accuracy, in at least two ways -

1. Obviously, if you move your barrel (as any force is likely to do) obviously, shot placement changes

2. Also, if you could get ahold of slo mo video of a rifle barrel, your would actually see it flex slightly with the shot. this is OK, AS LONG AS its consistent. Free floated abrrels are consistent in their flex, non-free floated barrels are not.

Link Posted: 11/1/2004 12:53:34 PM EST

Originally Posted By JHP:
simple version....things that touch the barrel cause it to be less accurate




not good enough. But thanks. Im more intersted in why it works than the outcome..I know the supposed outcome!
Link Posted: 11/1/2004 12:54:03 PM EST
Not only are non-floated barrel less accurate, but things like the use of a sling, accesories on RAS or resting the gun on something can change the point of impact.
Link Posted: 11/1/2004 12:54:08 PM EST

Originally Posted By JHP:
simple version....things that touch the barrel can cause it to be less accurate



Hard to improve on that explanation to someone that owns one and doesn't even know what it is.
Link Posted: 11/1/2004 12:54:57 PM EST

Originally Posted By garandman:

Originally Posted By gaspain:
Im not really sure how it works despite myself owning a "freefloated" AR. Whats the science behind it?

so the handguard doesnt touch the barrel, whats the big deal ehh?



The handguard exerts a force on the barrel. Any force on the barrel can affect accuracy, in at least two ways -

1. Obviously, if you move your barrel (as any force is likely to do) obviously, shot placement changes

2. Also, if you could get ahold of slo mo video of a rifle barrel, your would actually see it flex slightly with the shot. this is OK, AS LONG AS its consistent. Free floated abrrels are consistent in their flex, non-free floated barrels are not.




It changes the barrels harmonics.
Link Posted: 11/1/2004 12:56:25 PM EST

Originally Posted By garandman:

Originally Posted By gaspain:
Im not really sure how it works despite myself owning a "freefloated" AR. Whats the science behind it?

so the handguard doesnt touch the barrel, whats the big deal ehh?



The handguard exerts a force on the barrel. Any force on the barrel can affect accuracy, in at least two ways -

1. Obviously, if you move your barrel (as any force is likely to do) obviously, shot placement changes

2. Also, if you could get ahold of slo mo video of a rifle barrel, your would actually see it flex slightly with the shot. this is OK, AS LONG AS its consistent. Free floated abrrels are consistent in their flex, non-free floated barrels are not.




Alright, I'll push the "I believe button", hmm though I'll have to think about it some more though. Thanks!
Link Posted: 11/1/2004 12:56:40 PM EST

Originally Posted By Combat_Jack:

It changes the barrels harmonics.



Flex, harmonics, whateva.

Link Posted: 11/1/2004 12:56:46 PM EST
You have to worry about vibrations - things that touch the barrel effect the vibrations.

You also have to consider that, with a sling, you actually can deflect the muzzle slightly when you're looped up - you need consistency from shot to shot, and 1: inconsistent vibrations and 2: a deflected barrel from a sling are bad for consistency.
Link Posted: 11/1/2004 12:57:13 PM EST

Originally Posted By Dolomite:

Originally Posted By JHP:
simple version....things that touch the barrel can cause it to be less accurate



Hard to improve on that explanation to someone that owns one and doesn't even know what it is.



Hey dick, I know what it does, I just didnt know why.
Link Posted: 11/1/2004 12:59:55 PM EST

Originally Posted By gaspain:
Alright, I'll push the "I believe button", hmm though I'll have to think about it some more though. Thanks!



We're talking about thousandths of an inch here, which at 100 yards might translate to an inch.

Think about it, as the barrel flexes, if it bumps into a handguard, the bullet is gonna be affected.

Tolerances and variances in the handguard will produce difference force "bumps" and therefore different points of impact down range.

Free float takes out that variable.



Link Posted: 11/1/2004 1:01:12 PM EST
[Last Edit: 11/1/2004 1:09:28 PM EST by Daytona955i]

Originally Posted By gaspain:
Im not really sure how it works despite myself owning a "freefloated" AR. Whats the science behind it?

so the handguard doesnt touch the barrel, whats the big deal ehh?



Really simple, when shooting at longer distances, the pressure you aid from using the sling can turn the gun one way or another. It is more complicated than that, but that's the simple way.

Alright... here's another idea... Gun is a precise tool right? In order to deliver the bullet to the same spot everytime everything should be as close to the same as possible. IE position of the barrel to receiver, and sights, along with the stock. Since you're holding the stock, there's a way to make the barrel independent from the pressure you exert onto it. IE bedding the stock, or free floating the barrel.
Link Posted: 11/1/2004 1:04:24 PM EST
Non-freefloated barrels are less accurate for a couple reasons. First of all, you can exert force on the barrel by simply holding it; the force is tranfered through the handguards and slightly bends the barrel. For example, imagine using the sling to steady your aim; you loop it around your upper arm. This makes your aim steadier, but the pull to the weak side can also affect the barrel. In less obvious ways, imagine a wood stock that touches the barrel. Something like the wood absorbing water can cause the stock to touch the barrel in different places, again bending it.

Barrel harmonic are another issue. When you fire, the barrel starts ossiclating as the bullet passes down the barrel. As always, if you want accuracy you need consistency. Slight changes in the place the barrel touches the stock or the forces applied to it will affect the harmonics differently every time. Better to remove the source of variation altogether by isolating the barrel from all outside influences.
Link Posted: 11/1/2004 1:04:33 PM EST
Here's an analysis of barrel harmonics. Al even says it's a fairly Simple one .

www.varmintal.com/amode.htm

The fewer variables affecting the harmonics, the more consistent the result (accuracy).
Link Posted: 11/1/2004 1:04:36 PM EST
Keep in mind that if you are shooting with irons only, unless you are an olympic shooter, your eyesight will present a larger margin of error than a non freefloated barrel.

Link Posted: 11/1/2004 1:05:18 PM EST

Originally Posted By gaspain:

Originally Posted By JHP:
simple version....things that touch the barrel cause it to be less accurate




not good enough. But thanks. Im more intersted in why it works than the outcome..I know the supposed outcome!



The impulse from the propellent charge can cause a semi-harmonic shockwave down the length of the barrel. Making contact along the barrel changes the resonent points like putting a finger on a guitar or violin string. Putting it at the wrong point makes a "wrong" note. This can impart variations in spin of the bullet as it leaves the barrel. Small errors there can have big results on the point of impact.

This is also why re-crowning a barrel, or having some material shaved from the end, can help bring your groups in as well. Others have speculated that this is why flash suppressors and compensators harm accuracy.

And I stayed at a Holiday Inn Express last night....

Link Posted: 11/1/2004 1:06:37 PM EST
When fired, the barrel basically behaves like a tuning fork. While the barrel is "vibrating".... (for lack of a better word), anything that comes in contact with it will dampen the harmonics.

The sling thing... on a standard AR, the front swivel is attached to the front sight tower, which is attached to the barrell. On a free float tube the swivel is attached to the tube.

With a conventiional AR, when you use the sling for steadying the rifle, it excerts a downward pull on the barrel.

Link Posted: 11/1/2004 1:06:57 PM EST

Originally Posted By DriftPunch:
Keep in mind that if you are shooting with irons only, unless you are an olympic shooter, your eyesight will present a larger margin of error than a non freefloated barrel.




Very true.

But of course, if you are match shooting, you want to eliminate ANY causes for inaccuracy.

Link Posted: 11/1/2004 1:07:24 PM EST
Geez, I wish I had them free floater thingies on my rifles when I went out on that boat trip. I might still have my rifles now.
Link Posted: 11/1/2004 1:11:09 PM EST
The military found that some of their shooters slung up tight enough to move the POI 4 MOA.
Link Posted: 11/1/2004 1:12:07 PM EST

Originally Posted By Combat_Jack:
The military found that some of their shooters slung up tight enough to move the POI 4 MOA.



No shit, thats incredible
Link Posted: 11/1/2004 1:18:16 PM EST

Originally Posted By Combat_Jack:
The military found that some of their shooters slung up tight enough to move the POI 4 MOA.



If you sling up the same, POI should be the same.
Link Posted: 11/1/2004 1:19:18 PM EST
Link Posted: 11/1/2004 1:19:23 PM EST
[Last Edit: 11/1/2004 1:20:06 PM EST by JHP]
you know people get advanced degrees for this sort of work...for more detailed info, I'd suggest doing some research on your own at a college library.
Link Posted: 11/1/2004 2:43:31 PM EST

Originally Posted By TeuffelHunden1775:

Originally Posted By Combat_Jack:
The military found that some of their shooters slung up tight enough to move the POI 4 MOA.



If you sling up the same, POI should be the same.



Just a guess here but I bet he meant "comparing two different shooters shooting the same rifle." They prolly don't sling up the same.
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