I'm assuming it means nothing is pushing on the barrel effecting the accuracy?

Is this really a issue?

I mean I think I have braced my rifle against all sorts of things.

 

It means that from the attachment point at the receiver forward, there is nothing touching the barrel. IOW, the barrel touches the receiver and nothing else. IIRC, a gun will normally shoot "away" from an object in contact with the barrel, such as holding the barrel against a tree.

What are you trying to do with the rifle?

No offence but...........you have 13k posts on ARFCOM and don't REALLY know what a free floating barrel is ?

Yes, it is really an issue. And it is a key reason why ARs can be so accurate vice other semis.

Anything touching the barrel can effect harmonics and effectively change the zero. How much depends on different factors, like barrel thickness, length, where it is being touched and how hard.

You should not use trees or anything else as a rest for the barrel when shooting.

e-v-e-r soooooo gently , place it horizontally atop the meniscus.

like a needle.



j/k.  What these guys say is true. on the projectile's travel, it induces a spiral bullwhip effect in the barrel. Letting it do it's own thing, unimpeded,
makes for consistent placement as long as you do your part in stabilizing the weapon.

No physics buff here....

I'm also a 1911 fan, OP.


'03

I think I know what it is but a guy in a thread was saying how some retard was shooting from a sandbag with a free floating barrel?  I dont get why you couldn't do that  if its free floating why would a sandbag matter?

I'm not really in to long range shooting or custom AR's. All my AR's have been working guns.  And if I can hit a man sized target at 400 yrds with irons and a stock gun what more is needed?

This.  Frankly, I doubt it will affect the average shooter's accuracy that much.



 

Don't feel dumb OP, I didn't know either until now.  That's why I come to this site, to learn...and laugh most of the time.

A barrel will vibrate after the round is fired.  Anything in contact with that barrel will effect the vibrations differently after each shot due to differences in pressure, hold, etc shot to shot.  A free floated barrel lets it vibrate the same way each time, thus removing a variable, and making it more precise, shot to shot.  

Ohhhh , ok cool !

Many long range hunting rifles have free float (well the better ones anyway) ever see somebody take a dollar bill and slide it between the forend of the stock and the barrel and it didn't get hung on anything going in or out,  thats a free float !

Maybe he had the barrel resting on the bag, instead of the stock?  That would bypass the free floaty-ness of the barrel.  Everything would be all dis-harmonic and stuff.

More importantly, will a rifle with a free-floated be lost in a boating accident, or will it bob to the surface after initial immersion?

Very true , good point !

In that thread the BARREL was on the sandbag.



 

Just look at the guy's screen name.

And for the guys that say 'It don't make much difference', put a target out at just two hundred yards. First sling up real tight and shoot a group (using a rifle that is NOT free floating the barrel). Then, same rifle, target and distance, sand bag the rifle (under the hand guards, NOT touching the barrel), and shoot another group. Note the difference of POI between the two groups.

With my 20 inch H-bar, it means the difference between being in the 10 ring vs being clean out of it. Not only will you find different PsOI, most likely the sand bag rest group will be smaller. The tighter you sling up the bigger the difference in POI. Hence, many NRA High Power shooters use a rifle with a free floated barrel.

On an AR15 it's less about accuracy and more about mounted items holding zero.

Mine sunk

This

slomo ak47  http://www.youtube.com/watch?v=xeeeFxA_9nA&p=DF2C5EE7C569DA63&playnext=1&index=7
non free float.

Chuck Hawks believes that free floating is the gun company's way of cheaping out on proper bedding.  

I think it also keeps the barrel from settling down in a different spot in the stock after the vibration from each shot.  

average arfcom boa or average shooter moa?

bank of angle..
minute of angle..

and yes you can see a difference.. all rifles that I make are free floated the only ones I do not float are the ones with extra lugs on the barrel (safari big bores)..

Oh wow that is stupid, and why the hell would you ever lay a barrel on anything?

IME, sling pressure is the biggest reason to freefloat.

Slung up tight you can see a fairly dramatic difference free-float vs. non free float.

And although I haven't tested this, I would imagine that even using a rail-mounted bipod on a non free float forearm would cause some minor POI shifts.

Ehhh, don't feel to bad about it, I'm still not 100% on the difference between an open an closed bolt gun

Here's why it's important.  

When the bullet travels down the barrel, the barrel torques.  This produces a "whipping" motion in the barrel.  The barrel literally vibrates like a bell does.  When the barrel is not touching anything, it vibrates pretty damn close to the same each time with the barrel in almost the same point of torque when the bullet exits the bore... The vibration is like the tone of that bell.  Like a bell, when you lay it up against an object, the tone of vibration changes.  the pressure on the barrel can change due to temperature, humidity, altitude, etc. as well as the set of the barrel against the object.  This creates an inconsistancy in accuracy that is capable of having dramatic effect even at short distances.  

Now, you can fully support a barrel as long as the support is constant and tight.  There are supported barreled rifles out there that easily capable of 1/2 or better MOA.  It's a lot easier to get the accuracy by free floating.  You also get a significant weight savings.  

For some people, the need for accuracy cannot be overstated.  Law enforcement "snipers" may need to engage a hostage taker with only an eyeball exposed.  The difference between a rifle that shoots 1/2 an inch at 100 yards and 1 inch at 100 yards could mean the difference between life and death to the hostage.  They aren't shooting at people at 1000 yards, but they could literally be shooting at a target the size of a gum ball at 100.  They damn well better have a rifle capable of doing it.  99.9% of them will want a free floated barrel on that rifle.  

Close bolt is when the bolt has secured the round in the chamber and the cartridge is fired by striker or firing pin being hit.  Open bolt is when the bolt is in firing position when it's cocked back behind the round that is sitting in the magazine or feed tray.  When the trigger is pulled, the bolt is released and moves forward under spring pressure, stripping the round, chambering and firing.  The difference is how much mass is being moved to detonate the primer.  One is just a striker or firing pin, the other is the entire bolt or bolt assembly.