Why Floating a Rifle Barrel Increaes Accuracy
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- Опубликовано: 6 сен 2024
- Floating a rifle barrel isn't magic. In this video from The Survival Podcast www.thesurvival... we discuss why floating increases accuracy and the effects of barrel harmonics and oscillation. The rifles in the video are a Savage 110 in 308 and a NEF Handi Rifle in 30-06.
It's important that people understand that free floating your barrel will improve some rifles! If you have a high power rifle with a long, skinny barrel your rifle may shoot significantly WORSE by free-floating.
The idea behind free floating a barrel is to decrease interference with the barrel and its harmonics. However, certain long and thin barrels require reinforcement from the rifle's stock to shoot accurately. Examples of these include the SMLE and Mosin Nagant rifles.
100% correct. For example, Weatherby Vanguards with the #2 contoured barrel shoot sub MOA non-free-floated out of the box. Free float it and the accuracy will likely diminish.
Some mosin nagants will shoot better or worse after freefloating.
It depends..... contact your firearm manufacturer.
I have a 300 savage that was made in 1958. It is a family rifle but shot 2.5 inch groups ;-( I has a two piece stock with a screw in the middle of the fore end. I looked and noticed that the fore end wrapped the barrel pretty tightly as well. I decided to see if I could modify the fore end to get it to shoot. The head of the screw attaches to the barrel via a square flat 1 inch diameter head that fits a slot in the barrel. Here is what I did. I removed enough wood from the fore end to give about 3/16 inch clearance all the way down the barrels length. I then took an aluminum hunting arrow and cut it off at about 1 inch (you got to measure on your rifle). I drilled out the screw hole in the fore end to give a circumferential 1/8 inch clearance around the arrow piece and filled the outside of the arrow piece with JB weld. Now the only place the barrel touches is on the end edge of the arrow piece and the square screw base, if that makes sense !! Bottomline is that my 300 savage now consistently shoots 1/2 inch groups !!! That is amazing to me !!!!
Actually, floating a barrel only enough for a bill to pass under is not enough.... Barrel harmonics is only half the issue requiring floating. Stock flexibility is the other half. Depending on the stock you should have .04-.06+ under the barrel. A good test to see if you have enough float is to lightly tap on the for end with your palm.(compressing the fore end towards the barrel) you should not feel or hear the stock contact the barrel. A stock can flex quite a bit with even the small amount of pressure exerted by a sling or even sitting on a sand bag. A cheap synthetic stock may never pass this test, but a good quality stock (wood or synthetic) will do well with .04-.06" float. Every firearm will need a different amount of floating depending on the stock construction, barrel profile, material, and the caliber... Generally a bill is not enough though.
@Montyfiable look. accuracy is determined by the position of the bullet landing with reference to the direction the gun was pointed, consistency is determined by the distance between one bullet from the next.
@varun009 - What I mean is that a gun that has tension on the barrel will shoot differently as the pressure changes even with a "cold bore shot". Additionally as you zero your rifle that barrel will heat up, that changes pressure on the oscillation and you put it away happy. Now you go to shoot at game cold bore and your shots are hitting differently.
It's the amplitude not the harmonic frequency that varies when you "smack a steel rod" harder or softer.... Do a little refresher on frequency response (the frequency is fixed based on the material and geometry).
Floating allows for irregular/variable damping to be eliminated..
There is a reason for "heavy" barrels (increased frequency) beyond just thermal expansion.
Thanks for the feedback. I won't worry about finding my snap caps for my NEF then since I now have an area I can dry fire and have a target across the garage to make sure I don't flinch when I pull the trigger.
@jsore14 You can float a synthetic stock as well. It is generally considered to not be as necessary simply because they don't swell in humidity, shrink in cold, etc. That said the barrel does heat up when fired repeatedly and that varies pressure so there is definitely something to be gained.
Well, the question I would like to ask is: "does the oscillation occur while the bullet is travelling through the barrel?" Or "after the bullet exits the muzzle"? We will need a high speed camera to prove it
I thought that was a good question so I went looking. Thought you or anyone else interested might enjoy this article: www.guntweaks.com/barrel-harmonics.html
I read in Rifle magazine that a proper free floated barrel will not make contact between the stock and barrel if you take one hand and attempt to press them together. If they don't contact each other then it's done right. I had to do a little more sanding on my 06's stock after reading that. Makes sense though and just use light pressure.
@varun009 When talking about firearms, accuracy is interchanged with precision. All bullets are in the direction the gun is pointed, and the more consistent the rifle is, the more precise it is.
I personally use dry fire training for trigger control and form training about once a week. I own several NEFs, ARs, Lever Guns, Semi Auto Hand Guns, Revolvers, 22LR rifles like Rugers, etc. I try to do a rifle and a handgun each week, maybe 50 shots each and grab something different each week. The handis get a lot of work because you have to focus more on trigger control and cocking for a second shot is so simple. None including the NEFs have ever failed, none misfire, none have any issues.
@bottle2lip - It is never "necessary" but barrels and stocks will fluctuate as much with temperature as humidity. So if you have contact there will be a difference in harmonics from the warm early season to the frigid weather of the late season, as well as from when you have that rifle in your warm house and go out into minus what ever you are going to have to deal with so far north.
I have a savage 110 and I have the barrel bedded all the way up the foreend of the stock. this was a common practice back in the day. I say back fifteen to 20 years ago. With reloads i can shoot less than a quarter inch at 100 yards. The problem is when the stock has uneven contact with the barrel. While free floating the barrel is better than uneven contact, it is not better than bedding the barrel up the forend.
thank you this was very helpful to me, iv been around hunting rifles all my life an now am actually getting into the tech/spec side of guns
Jack,That is probably the best explanation of free floating, Thank you so much.
@ss19800 - Bedding and floating are 100% completely different things. Floating is about the barrel and removing contact. Bedding is about the receiver and ensuring contact. Many people "free float a barrel and bed a receiver" but the processes for each are totally independent and one doesn't require the other.
Jack Spirko I have 1983 Smith & Wesson model 1500 bolt action. Wood Monte Carlo stock. No floating what so ever. Gun shoots .25 or better MOA. Usually hole in hole. I found a video where a guy did the opposite of free floating. Took a 22 that shot horribly. It was free floated. Added a wire clamp and cinched the barrel against the stock. Then shot lights out.
@starr8719 - If you mean variance in how uniform the space between the barrel and stock are, it really doesn't matter. As long as the two don't make contact it is irrelevant as to the variance of space between the stock and the barrel. If they do not touch they do not effect each other.
The harmonic is consistent the point at which the bullet is exiting the barrel in the wave is the issue. It's like fretting a guitar. You change the "note" or frequency by the contact points with the barrel
@joslinnick bull barrels absorb more heat hence they dont "walk" or shift as much after putting more rounds through it versus a thin barrel.
@varun009 - A gun either is or is not consistently accurate. Just because you may only fire it once at game doesn't change that.
@survivalpodcasting - Additionally many people will coat the barrel channel with bedding compound but that is to "protect the float". In other words ensure that moisture doesn't cause expansion and contact isn't resumed. Yet a floating barrel simply means nothing touches it.
I can understand the confusion the two terms are so linked in a world where people are trying to squeeze ever drop of accuracy out of a rifle.
@joslinnick - Sort of, since it is more rigid there is less, but you still have it. The key is it is more consistent. Of course the weight of the barrel helps with general shooting as well.
Accuracy is hitting what you aim at; precision is hitting the same spot with the same inputs (aka repeatability). Floating preserves repeatability by reducing zero shift as the barrel heats up, and buy facilitating consistent barrel harmonics. This is valuable in the field, as in training.
@survivalpodcasting I'm not sure if I agree with your statement "they don't oscillate", as it's power plant dependent. An airgun with a pre-charged pneumatic power plant I could understand, but I believe that airguns with a spring power plant could potentially benefit from being free floated, if they had a stock that they sat into, which the majority do not. On the other hand I think bedding the action into the stock could yield some good results. Anyhow that's my two cents.....
@varun009 - That has absolutely nothing to do with anything. You are assuming the only time floating improves accuracy is when you fire multiple shots. That only barrel heat effects tension on the barrel from the stock. Many other factors do such as the temperature of the environment, humidity variations, how the weapon is held, etc. So if you zero at 800 ft elevation, in Sept with humidity of 70%, on a bench. Later you are at 5200 ft, hunting deer, humidity is 20% resting on cold ground.
@survivalpodcasting I agree 100% with you, I've never had a centerfire rifle's firing pin break from dry firing. Iv'e shot, and dried fired a garbage davis 380 pistols and the slide eventually cracked and the firing pin never broke. And that slide didn't lock back so it got dried fire a good bit. However I did have one bad experience with a Taurus pt 22 .22 RIMFIRE pistol. After very few accidental dry firings, the firing pin broke like glass.
...So I then added a small square pillar of hockey puck in the stock inlet at the end of the forearm hoping to provide steady/even upwards pressure.
Accuracy got even better and managed to finally keep up with my full wood original M38 Swede. I'm sure if bubba had added the original forward barrel band on the new rifle stock it would improve barrel harmonics further. But I'm problebly at the limit of the crappy plastic stock, which I know flexes a bit.
Anyway...So I totally agree with you...
great informative video. i wasn't aware of floating the barrel til i bought a stevens model 64 with a floating barrel. I'd hunted as a kid but never considered pressures against the stock due to weather.
Almost a perfect analogy, but I think it is not quite correct. I believe changes in the damping of the barrel (from humidity, temperature, etc.) change both frequency and amplitude.
As I understand it, with a low pressure round the frequency of harmonic oscillation is changed just as much as with a high pressure round, but the oscillation amplitude is so low that it does not throw the projectile off as much.
Think of the stock acting like a finger on a fretless guitar.
It would be interesting to measure the oscillations in a barrel and then transpose them to audible frequencies so that you can "hear" the oscillations in the same "notes" that are traveling down the barrel, and compare different setups.
I believe the barrel has a natural frequency. Free floating it avoids stock contact that can destructively interfere with the oscillations, changing the behavior. For sure, amplitude of oscillation should change with changing pressures as well. The only places where contact would not impact oscillation harmonics would be at nodes along the barrel...best to free float so that as much of the length is free from interference as possible. The Browning BOSS system tunes the natural frequency with an adjustable device at the end of the barrel for varying loads. Just another tech that plays upon the barrels natural oscillations under varying pressures. Of course, bull barrels also oscillate...but the amplitude of oscillation over similar loads is dramatically less.
Barrel Harmonics. Every barrel, when shot, will flex or move. Free floating the barrel allows the barrel to work or move. Sporter barrels, found on most hunting rifles have more flex than that of a heavy or bull barrel. Length of barrel does affect harmonics but that is a different topic.
@babbler254 - Well it isn't "necessary" to float any barrel but it is often helpful. Given the low pressures of the 17HMR and the stiff barrels they have to begin with it won't make a huge difference. It may help a small bit, most 17s are more accurate than the shooter to begin with.
Excellent info and video man, I've known that free floating increases accuracy but the way you explain WHY makes a lot of sense, thanks
I have a Savage 110 and not free floated the barrel but then I put a cardboard shim under the end of the barrel get damp in the harmonics this gun shoots sub 3/4 groups at a hundred yards it is also glass bedded in a wooden Factory stock there are so many things that figure into accuracy such as bullet powder primer and neck sizing only all these things have to be consistent from one cartridge to the next not saying that you are wrong but you should have mentioned everything else that goes into accuracy
Why do people insist on saying that floating a barrel ''improves accuracy''? It doesn't improve accuracy, it removes ''possibilities of inaccuracy''.
sounds an awful lot like accuracy ; )
No need to dryfire that rifle to take tension off of the spring. Lift the bolt now pull the trigger and keep it depressed while you close the bolt. This will unload the spring while not having to dryfire.
+Kris Bassett wow does this really work ive got to try it, your right man thanks. Im 49 years old and learned something new today.
+Kris Bassett Thanks for that tip, how have I not realized that before?
Hope ur being sarcastic...
Most basic safety lesson in long arms. How to safely carry a round in the chamber without having the gun cocked (ie. never trust a safety).
But then again (sub OP) is dryfiring an issue nowadays?
kadmow, While you are correct @kadmow, anyone worried about damage to a modern rifle due to dry fire is a moron. I am weary of explaining why, this myth is old an just won't die.
Thank you Jack so much . Hope you and everyone else has a Great Hunting Season this year and a Safe one also .
@survivalpodcasting this is why an experienced shooter will zero then let the rifle cool and maybe even clean the bore and shoot another shot to see where his cold and clean cold bore shot goes. i have found with my savage 22-250 the cold and clean cold bore shot will be in almost the exact same place every time so i can adjust for it.
My CZ was a little off beyond 60 yards. I floated the barrel and its improved quite a bit. survivalpodcasting is probably much more experienced than I, but that's what I found.
@BalazsDeathstar69Dry firing is a great way to create a smooth trigger pull for more accurate shooting. In military and police training its a technique that is emphasized to get a smooth trigger pull.
how does sliding the piece of paper under the barrel prove that it won't impact the stock after a shot is fired? is it reasonable to assume that the maximum magnitude of barrel displacement will be less than the thickness of the piece of paper?
Actually no that isn't reasonable. It is a solid piece of highly engineered steel and it isn't like a wet noodle when fired. Additionally is as I explained is more about pressure points on the barrel at time of discharge then something impacted after discharge. The bullet to be blunt leaves the muzzle awfully quickly.
+Jack Spirko of course it isn't a wet noodle but a paper bill is like 3 thousands of an inch and the barrel could expand that much and I'm sure it does. Free floating doesn't affect accuracy as much as people seem to think. The swiss K31 is a highly accurate rifle and is only partially free floated. It is more about consistency with the stock and the barrel.
What does hardness have to do with deflection when firing?? The overall hardness/strength has (almost) nothing to do with its elastic modulus (intrinsic property unaffected by heat treatment).
if one were to place the gun it on a rest and see if you can make the barrel contact its bed (with hand pressures), you can be sure it will do such when firing, more of the "issues" with floating etc are to do with variations and flexing of the stock than overall movement of the barrel (unless we are talking about full length stocks).
Quick Question: Is the reason why a bull barrel is considered to be more accurate and consistent than a traditional barrel because the thickness of the steel allows for less oscillation?
You asked this ten years ago and he still hasn't gotten back to you. What a jerk hahaha
@survivalpodcasting No, if the forarm contacts the barrel, the barrel is not floated at all.
@monsterman27 heck yea, a heavy barrel will not oscilate nearly as much as a standard barrel
There are some centerfire rifles that dry firing can hurt, the NEF Handi-Rifle is one of them. Dry firing can break the transfer bar that is the safety. But most of them, no big deal
Very informative! This is really interesting talking about the kinetics and physics that go into shooting and how to adjust for it.
@SigmaBallistics - Unless you are shooting in the Olympics it won't matter. When you look at range of an air rifle any difference would be meaningless. When you get good enough to shoot off hand and make one hole at 10 meters you can start tweaking an air rifle. NOTE I am NOT saying I can or even intend to try.
Just like if you float an accurate center-fire and shoot it at 25 yards you will see little to no difference. Move out to 100 or 200 yards and you can see the improvement.
@captainpegs07 - sorry but you are completely wrong about that. Again check out the Yahoo NEF/H&R group people have been floating them for a very long time. Actually bedding is what you can't do, as there is NOTHING to bed.
I had accuracy problems with an M38 Swedish Mauser sporter (6.5x55).
Sure enough bubba the gun butcher that owned the rifle before me just dropped it into a plastic stock...barrel was touching one side of the inlet.
So I floated the barrel buy using a small dowel wrapped in sandpaper and sanded the inlet down and guess what? The accuracy got better.
Then I remembered that the Finns used strips of brass in their captured Mosins.
So I then added a small square pillar of hockey puck in the
You want accuracy .
Glass the bed , float the barrel, reduce trigger pull to about 2 pounds , and reload your own ammo in 2 grain of powder increments and go shoot. The charge you get the best group is your base line. Next reload a grain above and below the base load. Shoot the groups again. Dial in on the correct charge.
This was an excellent video sir. Thank you, and I hope you continue to upload more to youtube.
whats the point of floating the barrel on a single shot bolt action rifle? i mean the opoint of floating is not to increase accuracy but consistancy and as it is that's not possible with a single shot since you have to constantly reload your weapon. however this would make sense with the barrett m82. other than that great video i learned alot!
Oh, and another problem I found with my synthetic stock was that I could get beautiful tight little groups from a sandbag rest on a bench. Then when I'd put a bipod on and fire prone the point of impact would shift up. Plastic is shit.
@awsomeshot also true i did it before with my remington model 700 7mm rem mag and i cocked it for the 3 hour drive down cuz in my state if there is a bullet in the mag they can arrest you so when i pulled the bolt back it cocked it then when i loaded it the next morning it was still cocked so then we took it to one of the best gunsmithes in the US he said the spring was worn out and we had to buy a new one off him the the rest of the week all i saw was does and on spike
@mbcyclery - no but people do keep asking.
Jack you are the man you helped open my eyes thank you...299 days is an awesome story thanks for interviewing Glenn Tate
I wonder if floating the barrel on an air rifle would help the accuracy as well.. I just bought a .22 RWS Model 48, but it has the screw in the arm like that NEF Handi. I mean.. I'm really not looking to snipe a rabbit at 300 or even 100 yds but I'm just thinking whether it would help the accuracy. Probably not, since these RWS air rifles have really great groupings right out of the box and likely don't get hot enough to have the usual problem that floating would fix.
I read it in the NEF section of the graybeard outdoors forum. It is also listed in the owners manual, but I am sure that is more a CYA/warranty thing than any thing else.
Have you also been dry firing your handi rifles for 15 years? If so, then I believe you that it won't hurt them. I can see how it could cause issues with the transfer bar, but also how if it wouldn't stand up to that, how much difference would a primer there to absorb some of the impact?
I've seen high-speed cams of an old Ruger Mini-14 with the pencil barrel and you can see the whip from the side. It would be interesting to see it from the top and see if there's any side twist besides the kicking up.
@triplewhiper Hey thanks for the kind words.
Theres plenty of videos on YT showing gun barrels wobbling and bending in slow motion.
@varun009 yeah if a bullet consistently hits 10 feet to the left than it is accurate because it is the same each time.
@awsomeshot i really dont know my dad used it for a long time the i went to cabelas and went bought a 300 mag and let him have it and i use the 7mm rem mag so its at least 15 years old
Would you say floating a .22LR rifle barrel would affect it's accuracy enough to make a noticeable difference? I have a marlin 25n with a synthetic stock, and it only attaches with one bolt, so I just put a rubber washer in where it connects to raise the whole thing up a little. Also does it matter if a little bit of the stock touches the barrel, or does the barrel have to be COMPLETELY free floating to gain any benefit?
@survivalpodcasting Can't flaot anything when there's a stock bolted to it.
So as far as floating the barrel, it's not really an issue unless you are shooting out over two or three hundred yards. Maybe longer?
The consistencie problem with the Handi Rifle is typically cause by the shooter. The long lock time by the actual hammer and people having the knowledge or the ability to hold after the shot. You have the same problem with people shooting pellet rifles because the pellet is so slow out of the barrel. I have one in .308 that is sub .5 MOA at 100 with standard factory ammo.
Good thorough explanation that was not boring. thanks.
I wonder how much variance there is I noticed you used a dollar bill to check it.
so if you have a synthetic stock which doesn't swell would i free floating barrel not make a difference?
Free floating has nothing to do with the stock -- wood or polymer, or plain plastic -- what matters is bedding, not the stock material.
Free floating your rifles is where its at. Free floating is even being used by SOCOMS M4's. Pretty much every SOCOM unit, and even a lot of Specialized infantry units use the DD free floats.
@tmaxxmudin - You will notice that almost no modern arms have them. Why? They really screw up harmonics. Every point of contact creates another variable. Mostly you see this on older military weapons where ruggedness is more important than pin point accuracy. Military conflicts from the advent of guns up to fairly modern times were about volume of fire and reasonable accuracy. Not tiny groups. A man is a big target. In battle a wounded man is better then a dead one.
You mentioned the wood stocks will change with humidity giving an inconsistent oscillation, affecting precision. What about synthetic stocks? Should you expect any benefit from floating a synthetic stock?
Very informative video. I'm gonna practice this later on when I have a proper area to work on my rifles.
hi i wanted 2 ask ive heard of people glass bedding i never knew u could just sand the stock down my question is how much can u sand away?
how far back should you float it i floated my 308 where the barrel start to get bigger
Back to the receiver. (where the barrel stops, goes into the receiver)
But if you take your time between shots, wouldn't that let the barrel settle until you fire again? Like striking a metal rod, waiting until it stops vibrating, then striking it again. I imagine that when you go hunting, you would not be firing shot after shot repeatedly at a prey, so there wouldn't be a need to float the rifle barrel. Please let me know your thoughts on this.
No it simply doesn't work that way. It isn't the previous shots harmonics that are the issue.
Aren't all newer Savage's floating barrels?
Thanks for explaining about floating the barrel. I've always wondered what it meant when they said a rifle has a full floationg barrel. Very good info and seems to be pretty easy to do it. Now say you have a synthetic stock I assume you can do the same thing correct??
I remember shooting a small 1000 fps pellet gun way before i was of age to buy real guns. It was shooting fine without a bipod, but when i put a barrel mounted bipod on it and shot prone, my groups opened up a whole lot.
You apply pressure on the barrel that's why.
nice video and excellent explanation. i thought about floating my 91/30 but i've heard that it's better for heavier barrels. i think i might just do it anyway. :)
@varun009 consistency is accuracy
Nice vid bro. Very good theory, and not much work to tighten up those groups. I think I'll get started on mine tonight.
Wont you have barrel chatter because now there is a gap
What if you have a synthetic stock? And I have been debating on whether getting the Remington 700 or this Savage 110. Any suggestions? Or any other guns that you guys know of that are good but not too expensive?
Barrel floating doesn't increase accuracy. Floating the barrel helps eliminate the forces that cause in accuracy, opened patterns on paper. It also lets the barrel return to it's starting position with out pressure from the stock.
Question for ya. You mentioned specifically in this vid, wood stocked rifles.
WinI have a Remington 710, a polymer stocked rifle (in .270 Win). Are polymer stocks affected the same way?
Thanks, keep up the good work.
will barrel thickness make a difference in harmonics?
I've never heard that if a barrel is long free floating it may make it shoot worse. Can you elaborate on this please ? Thank you .
If the round is supersonic and leaves the barrel faster than the speed of sound how can it be influenced by wave phenomena that is limited to the speed of sound? If a sight is tuned into the muzzle I don't think free floating can make any difference if shooting supersonic ammo. Also if you are rapid shooting you would want a dampening mechanism less you induce oscillation and make it worse.
Sounds move much faster in mediums over air
Two points to ponder. First, sound travels at 16,000 feet per second thru steel. Second, over 98% of the comments show that there is no grasp of even basic
nomenclature, and you think these people offer a
"informed" opinion?????
Thanks man. I wanted to know what was up and I got it.
@captainpegs07 - actually I think that is about you. You know what the internet tells you.
Awesome info... Hey, is there an easy way to float a synthetic stock? My buddy just bought a Savage Arms 111 .243 ... i was just wondering if we could float it without to much work.. or would we need to buy a stock specific made for float and reattach the hardware?
Awsome well explained, cheers
Thanks Jack, helpful and informative as always.
Never free float a barrel until the receiver is bedded. Also bed the barrel, depending on the gun, a short distance for good barrel support.
I think the guy was a little irresponsible in the way he presented free floating. He made it sound like all guns will benefit from free floating and that’s just not true.
@captainpegs07 Do you even know what "float" means. It means to remove contact between the forearm and the barrel. One can easily float the NEF/H&R right up to the forearm screw. One can also use what NEF enthusiasts call "the rubber washer trick" to float it past the screw all the way down to the claw lock at the receiver. Once done the only point of contact is the washer around the screw, this "floats" 95% or better of potential contact. Sorry you are just wrong, facts are stubborn things.