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Posted: 1/3/2006 3:46:44 PM EDT
I have heard that free-floating isn't practical for those who don't use match ammo. Is this true?

I know that free-floating will prevent POI from shifting. Are there any other ways it improves accuracy?
Link Posted: 1/3/2006 4:23:14 PM EDT
With my factory Bushmaster barrel and LT 13.2, I was getting 1MOA groups, with Blackhills BB 55gr Ammo. For me free-floating helped.
Link Posted: 1/3/2006 11:29:40 PM EDT
Anyone else?
Link Posted: 1/3/2006 11:32:42 PM EDT
Link Posted: 1/4/2006 3:49:53 AM EDT
[Last Edit: 1/4/2006 4:12:51 AM EDT by BlackandGreen]
.........don`t forget about the fact that you are not stressing the bbl by hanging extra items....sling pressures etc........my factory armalite with nm bbl will do similar groups or even better.....than my varmint homebrew .....but....mounting the bipod won`t affect the varmint gun accuracy...or anything else that my hang on the forend...........the tube takes the grief not the bbl.....so when i fall down in a drunken haze while carring the free float into the house....hopefully the bbl has a chance to stay put........
Link Posted: 1/4/2006 4:04:51 AM EDT
Another factor that I don't see mentioned often is that free floating gives the barrel the ability to expand as it heats up from sustained fire without deflecting because there are no contact points between it and anything else.

Not all non-free floated barrels shift POI as they heat up, but they are rare. That goes for ARs as well as conventionally bedded and stocked rifles.
Link Posted: 1/4/2006 3:54:59 PM EDT
I heard that barrel harmonics will also be more consistant. Is this true? If so, how much of a difference does this make?
Link Posted: 1/4/2006 5:24:45 PM EDT

Originally Posted By spork:
I heard that barrel harmonics will also be more consistant. Is this true? If so, how much of a difference does this make?


They will be more consistent for the same reason I explaine din my previous post: the barrel has nothing hindering its free and natural vibration.

Every rifle barrel vibrates as a bullet and mass of expanding gas travels down the bore and exits. If a barrel has pressure points along its length (i.e., it is not free floated), the pressure exerted by the barrel on those contact points will change due to the barrel's thermal expansion as it heats up from firing. Those pressure changes change the harmonics (vibration patterns) of the barrel. What that means to accuracy is that the bullet will exit the barrel at a different point in the vibration cycle. Essentially, the muzzle is not pointing in the same direction at the moment in time when the bullet leaves compared to when it was colder.

A free floating barrel will expand as well due to heating, but will do so radially in a uniform manner because nothing is touching it or restricting its motion anywhere along its length. The muzzle is always in the same spot along its vibration cycle when the bullet passes by, which means a much more consistent point of impact.
Link Posted: 1/4/2006 5:37:36 PM EDT
[Last Edit: 1/4/2006 5:52:13 PM EDT by theshootersden]

Originally Posted By spork:
Anyone else?



SWO_daddy has an OK explanation but I'll try to explain the way I look at Free Floating the barrel for accuracy...

Barrel whip happens when the barrel vibrates up and down and in a circular motion when being fired... Although there are some up and down vibrations, the main vibrations are circular... If this were not true, then a 3 shot group from a rifle would always be in a vertical string... Most 3 shot groups you will see will be virtually triangular in shape, this is caused because as the barrel vibrates through its "circular arc" one bullet leaves the muzzle at say 12 o’clock, another at say 4 o’clock and the third at maybe 8 o’clock... The larger the arc of the barrel, the less accurate the rifle will be, and the larger the triangle... As a rule the less mass a barrel has (the thinner), the more it is affected by the vibrations, this is the reason that a "heavy" barrel seems to shoot more consistently than a thinner barrel...

Builders of accurate rifles agree if the barrel's movement can't be eliminated, the next best thing is that it move consistently with each shot... That's why good shooting rifles have stiff "heavy" barrels and their actions are firmly bedded in the stock with nothing touching the barrel in front of the receiver (Free Floating)...



ETA:

Originally Posted By spork:
I have heard that free-floating isn't practical for those who don't use match ammo. Is this true?



Free Floating will help improve accuracy with any ammo but will sustain better accuracy when using match ammo...
Link Posted: 1/4/2006 5:46:49 PM EDT
Free floating does not make a barrel not string as it heats up. Many bolt guns have barrels that purposely make the stock contact the barrel to keep POI shift down as the barrel will walk more when free floated with a thin hunting barrel.
Link Posted: 1/4/2006 5:55:30 PM EDT

I have heard that free-floating isn't practical for those who don't use match ammo. Is this true?


This is a true statement. if your going to shoot the common 5.56MM surplus XM 193,Q3131,Wolf ect, the free float will not enhance your performance to a level where the average shooter with average skill is going to notice. Most shooters are average skill level. Just a plain fact. if your not going to enhance your accuacy with good ammo, why bother floating the barrel.

Link Posted: 1/4/2006 10:40:50 PM EDT
Thank you very much for the info. I'll will go with the free float.

Does anyone know when the Midwest Industries free float forearm for midlengths will be available?
Link Posted: 1/5/2006 12:59:27 AM EDT
I just did mine becaue I thought it would help cool the gun down faster and looked kewl... IT seems to do the job too, i dont' know if it cools faster or doesnt' get as hot but it sure SEEMS to be cooler to the touch.


plus i wanted to try and put it together for the first time
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