Free floating barrel - whats it mean?


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Lightsped
December 16, 2007, 12:21 AM
Without getting too complicated, can someone kindly explain to me what exactly a "free floated barrel" is? And what are the advantages/disadvantages to such a feature?

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jerkface11
December 16, 2007, 12:33 AM
It means the barrel doesn't touch anything but the threads on the receiver. The advantage is better accuracy there aren't any disadvantages.

trueblue1776
December 16, 2007, 12:47 AM
When companies figured out it was cheaper to float a barrel than to bed it well and make it fit the stock, it became all the rage. Take it how you will, floating does not mean accuracy, and it doesn't equal quality.

Float Pilot
December 16, 2007, 01:19 AM
A rifle barrel vibrates and whips during firing. The heavy , thicker barrel less so.
If you sight in a rifle that has no forestock (say in a vice) and then push your thumb against the barel for the next few shots, you will see that the group will move. That is because you have disturbed the harmonics (NODES) of the barrel.

If a high quality stock is properly bedded against the barrel, it will always be the same and nothing will change. BUT, some stock material like wood, will change its shape and density over time due to moisture content changes.
Particularly on less aged wood or improperly cut stocks.

ON ONE HAND: Free floating means they could simply make the barrel channel larger and thus reduce the fitting time of commerical wood stocks. Particularly back in the 1960s when Winchester and Remington put out some real junk.

BUT, on the OTHER HAND: A free floating barrel seemed to be fairly consistant in its accuracy. If that rifle and barrel like the ammo being shot. (remember the BOSS system also changes the harmonics or node length of the barrel)

Some companies free float all of the barrel except a PRESSURE POINT. Sometimes this raised
area in the barrel channel looks like a vie or two bumps. This seems to be popular with light whippy barrels on mountain rifles.
Even then, an improper stock fit will make your groups wander once the barrel heats up. And yes, it is still possible for them to make improperly fiting synthetic stocks.

Another method is to completely glass bed the barrel channel. This also works rather well, but it adds some weight to the rifle.

I have attached a couple photos:

One is a group fired from a Remington 30-06 M-700 titanium Mountain rifle with the factory pressure points in the plastic stock. Another is a photo of the group after free floating the barrel entirely. Please note that the groups dropped 8 inches at 100 yards after removing the pressure points. Both groups were fired while the bore was dirty from 20 previos shots and it was still hot. That barrel heats up after 3 rounds. This was sandbagged at 100 yards. As you can see it is not a tackdriver but it is lightweight.

All in all, some improvement with that load. Going from a huge 8 inch type non-group to a 2 inch group. , but the rifle is now more picky about which bullet weights it will shoot. In fact now it will only shoot 160 to 165 grain bullets. All will touch if you let it cool for 10 minutes between shots. Partially because the barrel is thin like a soda straw and heats up much to fast. The pressure points must have held the barrel a little better during the heating process before I free floated it. A bunch of BS for a $1,200 rifle.

I am going to try to post another photo of an custom 7x57mm M-98 Mauser that I glass bedded into a thumbhole stock back in 1975. The entire barrel channel is bedded so the barreled action actually pops into the stock and stays there without the action screws. This gun will still shoot 1/2 inch groups at 100 yards after 30 plus years of shooting and hunting with it. It has a nice heavy Douglas number 5 taper barrel that is 20 inches long. The stock is English Walnut from a Fajen stock blank.

SprayAndPray
December 16, 2007, 12:20 PM
Glad this subject came up since i have a few questions.
Can an AK or AR have a floated barrel? I mean they have gaschannels and stuff plugged into the barrel.

This leads to my next question, the Walther WA 2000 seems to have 2 long bars or rods (maybe som kind if gassystem) going almost all the way down to the muzzle where they end up holding the barrel. It looks rigid and sturdy to me.
The Walther is known for good accuracy but its does not have a free floated barrel.

The question is: if you make something holding the barrel in place rigid enough then you dont need to care about free floating at all??

What happens to resonance and harmonics and stuff when you do this to a barrel ("locking" it in place or mounting it really solid and sturdy)?

Could rifles actually benefit from this vs free floated?

duck911
December 16, 2007, 12:47 PM
It's all about "your gun."

I've owned or shot rifles that needed to be free-floated to shoot well, and I've shot rifles that were full length bedded for the best accuracy. I even once owned a .22 rifle that shot the best with a piece of card stock folded and placed right at the end of the forearm, putting a little upward pressure on the barrel (I later epoxy bedded a little "hump")

Only YOU will know what's best for your rifle, and that takes range time.

It's been my experience that some guys are way too quick to start sanding away wood. Sometimes, I see folks free-float barrels before the gun is even taken to the range. I consider free-floating or full length bedding a solution to a problem, not something that all of my rifles will have by default and not necesssarily the best thing for accuracy.

That's my .02.

motorep
December 16, 2007, 12:56 PM
Plenty of ARs have floated barrels. Early on it was discovered that the downard pressure of a sling, or the upward pressure of a bipod would change point of impact. Mounting these on a floated forend eliminates this.

SprayAndPray
December 16, 2007, 01:27 PM
I was led to believe that free floated meant no contact whatsoever with other parts than the threads/mount in the reciever.

motorep
December 16, 2007, 01:41 PM
Let me clarify- on ARs with the typical 2-piece handguards, the handguards touch the barrel, and slings/bipods are attached to the handguards. With a free-floating handguard that's not the case.

YodaVader
December 16, 2007, 02:17 PM
Most heavy barrel factory guns will be free floated and the most accurate rifles out there - custom benchrest rifles are all free floated. If there was some accuracy adavantage to be gained by spending time fitting a barrel channel to conform to a heavy barrel without free floating the BR shooters would be doing it.

The only factory heavy barrel rifle that I owned that did not come free floated was my 700VLS and out of the box it was the only poor shooting heavy barrel I have owned. Floating the barrel of this particular VLS allowed this rifle to shoot with a high degree of precsion that was not present before. But I have heard of those that say their results were still good with their VLS with the pressure point.

Now those shooting sporter profile or mountain rifle barrels say that barrel pressure is actually beneficial and some of the resons behind it make sense.

For my heavy barrel rifles the free floating barrel has given me excellent results.

SprayAndPray
December 16, 2007, 02:44 PM
What about the Walther-design, its not only a pressure point in the stock touching that barrel but its firmly mounted to the rods/bars over and under. Could this be a good way to go? I understand as the barrel gets warm then thing might start moving but lets say you never shoot til it gets really hot.

http://www.carlwalther.com/images/wa2000.gif
http://www.carlwalther.com/images/wa2k%204a10.jpg

lencac
December 16, 2007, 02:50 PM
A free-floated barrel is exactly what the term implies. A true free-floated barrel is where only the reciever is in contact with the stock. Free-floating barreled rifles can be very accurate. That is the entire purpose of a free-floated barrel, no other. A couple of disadvantages are, and there are a couple. One is the whole rifle becomes basically a precision instrument, meaning it is somewhat fragile and will not tolerate rough treatment without causing negitive effects on accuracy. Second is that although a free-floated barrel can be extemely accurate for the same reason it can be very picky about the ammo it will shoot with great accuracy. When a barrel is free-floated it is allowing the harmonics to become a hugh factor in it's operation. It's all about consistancy. Making the bullet come out the barrel each time in exactly the same way. If you look at the benchrest shooters without exception you will find that their very exspensive benchrest rifles all have free-floated barrels. But also you will find that without exception all their barrels are very heavy to dampen the harmonics. Rule of thumb. The lighter the barrel that is free-floated the more the harmonics are a factor. A light barreled free-floated rifle may have only a very small range of the type of ammo it will shoot exteme accurately.
The other option is to "hold" the barrel and thus reducing the harmonics. This is many times a better way to go on light barreled rifles, i.e. featherweight hunting rifles and up to and including most military bolt rifles.
A properly bedded stock, both receiver and barrel channel can produce a rifle that is as accurate as a free-floated rifle. Military bolt rifles that have a full handguard are particularly well suited to this because of the ability to really hold the barrel to the degree necessary. To do that though requires more technical expertise and understanding of the particular type of rifle being used. Free-floating a action and barrel is a relatively simple and straight forward process. A couple of bonuses of a correctly and completley bedded rifle are they are not as "fragile" as a free-floated rifle and they are almost certainly more predisposed to shooting a wider range of ammo types with exceptional accuracy.
Float Pilot, by the way that is a very nice post also. It is always good to share knowledge from ones practical experiences.
Here is a couple of pics of a custom built Remington 1903A3 with a Krieger Mil-spec barrel in full military trim that has been completely bedded from the rear tang of the receiver to the forearm at the end of the stock.

YodaVader
December 16, 2007, 06:28 PM
One is the whole rifle becomes basically a precision instrument, meaning it is somewhat fragile and will not tolerate rough treatment without causing negitive effects on accuracy.

If I am not mistaken the military sniper rifles in use based on the Remington 700 action are all free floated and I would say their rifles experience far rougher use than average and I would surely bet the rifles still perform. As far durabiltiy and still being able to shoot accurately after experiencing adverse conditions I would put my free floated 700LTR up agianst any other 700 that has a pressure point barrel.

I have found that my free floated varmint/tactical style rifles are relatively easy to load for and I do agree , it is all about consistency and the only time I did not achieve this in a varmint gun was with the 700VLS mentioned earlier that had a great deal of upward pressure on the barrel.

ROMAK IV
December 16, 2007, 06:47 PM
AR's will have the gas block touching the barrel and will be attached by the gas tube, but this is not a limitting factor since AR's can be made to have phenominal accuracy.

The Annoyed Man
December 16, 2007, 09:17 PM
I'm not by any means an expert, but I do have two different rifles chambered in .308. One is a Ruger M77 MkII with a lightweight 22" barrel that is not free floated. The other is a Remington 700 VSF with a heavy weight 26" fluted barrel that is free floated. If you shoot Federal's 168 gr SMK BTHP out of both rifles at 100 yards on the same day in the same conditions, the Ruger will print 4 shot groups in the 1"-2.5" range, while the Remington will print 4 shot groups in the .375"-.75" range. (The variations are all my fault.)

There is absolutely no question that the rifle with the fully floated heavy barrel is more accurate than the one with the unfloated light barrel. Admittedly, there may other factors involved, like trigger quality and so on, but I attribute the Remington's superiority in accuracy primarily to its barrel configuration and being freely floated.

gimposaurus
December 16, 2007, 09:45 PM
I'm not by any means an expert, but I do have two different rifles chambered in .308. One is a Ruger M77 MkII with a lightweight 22" barrel that is not free floated. The other is a Remington 700 VSF with a heavy weight 26" fluted barrel that is free floated. If you shoot Federal's 168 gr SMK BTHP out of both rifles at 100 yards on the same day in the same conditions, the Ruger will print 4 shot groups in the 1"-2.5" range, while the Remington will print 4 shot groups in the .375"-.75" range. (The variations are all my fault.)

There is absolutely no question that the rifle with the fully floated heavy barrel is more accurate than the one with the unfloated light barrel. Admittedly, there may other factors involved, like trigger quality and so on, but I attribute the Remington's superiority in accuracy primarily to its barrel configuration and being freely floated.


that's in no way at all scientific, they are completely different actions etc.

Do it with 2 rifles of the same model, make and calibre



Incidentally my ruger ultralight .223 went from 1" groups with random fliers, to consistent .4" groups after I floated the barrel.

The Annoyed Man
December 16, 2007, 10:22 PM
gimposaurus, you're absolutely right, of course. That's why I wrote "Admittedly, there may be other factors involved..." And there is nothing wrong with the Ruger action, per se. I actually like mine, and I kind of wish my Remington had the claw extractor like the Ruger's.

Sunray
December 16, 2007, 10:31 PM
"...the barrel doesn't touch anything but the threads..." It's actually from the chamber area forward that the barrel doesn't touch the stock. Action bedding goes along the barrel channel under the chamber area. A few inches will do.
Free floating does not guarantee better accuracy. Some rifles like it, some don't. Note gimposaurus' post. Rugers tend to not like a free floated barrel. Remingtons do.
The only way to find out of your rifle does like it, is to try it. If there's a pressure point, take it out with sandpaper and go shooting. If the groups get worse, putting the pressure point back in is no big deal. A bit of bedding material 1 or two inches aft of the end of the forestock(It's bad if the barrel touches the stock anywhere else along the barrel channel. That literally pushes the barrel off) will do it. Don't forget the release agent.
Make sure the wood in the barrel channel is sealed too. Moisture will get into it, expand the wood and move the barrel.

huaco
December 16, 2007, 11:06 PM
Glad this came up. Hopefully the parts to complete my first AR build will arrive Monday and I'll become one of those who knows all about them soon. I wanted to go realitivey KISS this first time so no float tube. Wondering if I should have today I thought back on what I know about floated barrels. My understanding is as described above, nothing touches the barrel so it can do its own thing consistently. Any gas operated semi has a hole in the side of the barrel and stuff attached to that area that connectects to other parts. Gas passing out that hole affects the barrel on firing as does the gas block and tube. As the block and tube heat up that affect is bound to change.

I'm sure there are lots of folks who will testify to the virtues of floating the barrel on a semi and they may be very right but I'm having a hard time seeing where it comes from. Some consistency improvement maybe but the harmonics are already seriously disturbed.

SteyrAUG
December 17, 2007, 12:12 AM
When companies figured out it was cheaper to float a barrel than to bed it well and make it fit the stock, it became all the rage. Take it how you will, floating does not mean accuracy, and it doesn't equal quality.

Consistent harmonics DOES equal consistent results.

Results of A may or may not be superior to B, but if A is "free floated" those resuls will be "more" consistent.

PercyShelley
December 17, 2007, 01:46 AM
I believe that the bars on the WA2000 were a barrel tension system. Putting tension on the barrel is supposed to keep it steady when the barrel heats up an starts expanding, IIRC the old bushmaster m17s and certain customs 10/22s have similar systems.

No idea what it does to harmonics.

lencac
December 17, 2007, 02:42 AM
An interesting firearm I have is an old original Remington 40X chambered in 22-250. It has a heavy barrel and the receiver has solid floor, no magazine and a heavy factory bedded wide forearm stock stock. In the forearm ofthe stock are 2 pads that are mounted to detented screws that allow you to put whatever amount of up or side loading on the barrel you like. I've played with that a bit and it really doesn't take much to change how it shoots.

The Annoyed Man
December 17, 2007, 10:18 AM
Note gimposaurus' post. Rugers tend to not like a free floated barrel. Remingtons do.Re-read his post. Gimposaurus's Ruger improved its accuracy by floating the barrel.

Just spitballin' here, but I think that pressure points in barrel channels overlook the part that consistency plays in accuracy. Let's say that your rifle is a tack driver and it has a pressure point built into the barrel channel, as the barrel heats up and the metal expands, the amount of pressure is going the increase. This will A) shift the point of impact by mechanical application of lateral force against the barrel; and B) change the barrel harmonics by changing the way the steel vibrates as the increased pressure is applied. Thus, you've only got a narrow window of X number of shots until the barrel heats up within which you can count on hitting your point of aim.

When you float the barrel, you don't have to deal with either of these effects. You would only have to deal with the slight change of harmonics due to the marginal softening of the steel as it heats up.

At least, that's how it works out in my head. I admit to having cobwebs in the corners of my mind. However, as gimposaurus pointed out, I'll have to buy myself either a sporter barreled Remington 700, or a heavy floated barreled Ruger (or both, if I can convince The Annoyed Woman), and test them one against the other to find out. It bears pointing out that Savage has been floating the barrels in its lower end "package" guns, and they have a reputation for out of the box accuracy, particularly for "cheap" rifles.

Seems like a perfectly good excuse to buy another rifle to me.... :D

Commander Guineapig
December 17, 2007, 10:25 AM
I just bought a Ruger stock for $10 that I am going to rework so it free floats my 10/22 barrel. hmmm...since I still have my unmodded stock I may need to do a side-by-side shootout...
My meager understanding of this subject says the same as some of these other gents:
the wood ends up applying pressure to the barrel based on many factors, thus altering accuracy.
GP

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