Mitigating Barrel Whip and Harmonics

[Deadduck1971]

BOSS. Browning and Winchester. You can tune your barrel harmonics to factory loads. It works.

I'm a hunter and new to long range accuracy shooting. I don't have any custom guns, but I have a Model 70 Classic Stainless Boss from the 90's in 300 Win Mag and the BOSS works. I can pretty much dial in any load. Cuts recoil too. Of course the trade off is noise and an ugly contraption hanging off your barrel.

 

[BigDon]

From what I have seen smaller/longer barrel contours can be very accurate but they are more finicky. The accuracy nodes don't seem to be as wide as with bigger profile/shorter barrels. Everything equal The harmonics are gonna be greater on the smaller profile longer barrels due to simple physics. This means ur reloading practices are gonna have to be very consistent leaving less room for error in neck tension/ powder charges/ temp stability etc. just my .02 for what it's worth.

But is there a point of no return? I have a 6.5-284 with a 30" un-contoured barrel. It is heavy enough that I'm concerned that it might be flexing the Remington long action itself. I wouldn't build one like this again. I didn't find either the accuracy or velocity gains I was hoping to achieve - and the balance is terrible.

 

[chindits]

So somebody school me here. So what of barrel whip and harmonics. If it is consistent from shot to shot, does it really matter? Or are you saying it will never be consistent due to differing ambient air temperatures effecting the whip/harmonics?

I don't care about barrel temperatures because I hunt elk not paper. If I shoot more than two rounds than something went wrong. I do the same when I practice, shoot two rounds and move my target. Plenty of cooling time especially past 400 meters of walk time in both directions.

 

[Toolhand]

But is there a point of no return? I have a 6.5-284 with a 30" un-contoured barrel. It is heavy enough that I'm concerned that it might be flexing the Remington long action itself. I wouldn't build one like this again. I didn't find either the accuracy or velocity gains I was hoping to achieve - and the balance is terrible.

Is the action bedded? If so how far down the barrel? Definitely think there is a point where barrel length becomes to long for various reasons. Weight, maneuverability, powder burn efficiency, etc. that being said I think 30 is pretty standard for long range bench work so may have other issues.

 

[Toolhand]

As long as the barrel whip is consistent then that's great but all I was saying was that inconsistencies will cause varying whip/harmonics which are amplified with a longer lighter barrel. For hunting purposes and the distances most people hunt it is for the most part a non issue. For bench guys trying to shoot tiny groups then it can be a big deal.

 

[J E Custom]

"carbon wrapped barrel deflected the same as a steel barrel of the same weight."

How much longer does a CF barrel need to be to equal the same weight? I would think length would be a factor in whip.

Dan Lilja did a test to see what the optimum barrel length is/should be that is a very comprehensive study and should answer any questions about this subject.

https://riflebarrels.com/barrel-lengths-in-the-338378-weatherby-magnum/

Here is another good study also.

https://riflebarrels.com/barrel-length-velocity-and-accuracy-question/

It is a great study done by a true expert and very useful If you are trying to size a barrel for optimum performance (Velocity and accuracy)

J E CUSTOM

 

[MBDave]

I use limbsaver barrel deresonators on a few of my rifles with very noticeable results! I have one on my custom browning 300 win mag 28" barrel and it improved my groups from 3/4 inch to 1/2 inch groups at 100 yards, however I have tried using it on my rifles that have shorter barrels with no results, ex on Ruger .243 22" barrel there was no noticeable change in accuracy! In my personal opinion for the few dollars they cost it is worth the purchase to try one on your rifles if it works Perfect!,, if not give it to a buddy!

 

[nicholasjohn]

I'm deciding on a barrel contour for a hunting rifle build (300 PRC) and my research on barrels has brought to light the question of barrel whip.

We know that heavier barrels are supposed to be more accurate, but I wonder what can be done to mitigate the loss of accuracy as one goes with a lighter barrel.

I have a theory that fluting a barrel helps mitigate barrel whip. Any thoughts on this?

I also came across a strange contraption on Amazon: "LimbSaver Sharpshooter X-Ring Barrel Dampener." For $9.99, people are swearing that this thing is helping their groups considerably. Is this for real? Is it only helpful to light-weight barrels? Why would this be okay but having a floating barrel be so important?

I don't have any experience with barrel dampeners, but I do remember many years ago when my buddies used their autoloading shotguns to shoot deer in slug-gun areas back east. These were the same guns they used to shoot called-in crows at VERY close range, and they had sawn the barrels off right behind the choke to open their patterns up for the close shooting. This left about 20-22" of barrel length on their crow guns. Someone figured out that these shorter barrels shot slugs more accurately, an it was determined that they were somewhat stiffer, and vibrated less than a full-length barrel. Then someone wrapped electrical tape around the barrel, to further dampen vibration, and pretty soon everybody was doing that. They were stacking up deer like cord-wood, and all was well. This all went away when they started selling rifled shotgun barrels for shooting slugs, but the dampened barrels shot surprisingly well prior to that technology taking over. You might try wrapping your barrel with about two dollars-worth of electrician's tape and see how I works before blowing the full ten bucks on the barrel dampening ring from Amazon. Make it about 1/4" thick all the way to the muzzle and see what happens. The glue will all wipe off with brake-free or gun-scrubber after the experiment. Good luck.

 

[Opa-lopa]

IMO, fluting a steel barrel removes mass w/o dramatically reducing bending stiffness, increasing the 1st mode bending frequency. Not sure that's an accuracy advantage. If there are residual stresses in the barrel, cutting flutes in the exterior will change the bore straightness, again whether that results in smaller groups is TBD. What's your theory behind fluting being more accurate?

 

[25WSM]

The heavier the barrel the wider the accuracy node.
Fluting is for looks and weight.
The more material the stiffer the barrel
The shorter the barrel the stiffer it is.
If ur handloading none of it matters, tune ur load to the rifle

Shorter stiffer barrels have smaller nodes. The frequency of the barrel vibrations are shorter meaning the barrel doesn't stay in the upper or lower part of the swing range for as long. A palma barrel has a much wider node than a heavy varmint. The size of the node doesn't mean more accurate it means more forgiveness to your tuning. Larger nodes stay in tune way easier. Think of the short fat barrels on a ppc gun. Accurate as all get out but really hard to keep in tune.
Shep

The heavier the barrel the wider the accuracy node.
Fluting is for looks and weight.
The more material the stiffer the barrel
The shorter the barrel the stiffer it is.
If ur handloading none of it matters, tune ur load to the rifle

 

[tacomHQ]

I think we would all agree: intended use is the primary aspect of choosing a barrel:
I am sure there are hunters out there who would be happy if their 300WM weighed 2lbs complete and would be happy to accept the unshod mule kick it will deliver.
Bench rest-it appears heavy is better.
ELR- while the barrels are heavy (20+ pds at times) their length proportionally makes them a lighter contour.
And everything in between.
Is it a one shot cold bore is the criteria, 3 shots, 5 shots, 20rds competition, fire fight unlimited. Each brings their own requirements. Trade offs and compromise.
Fluting does not make a barrel inherently stronger.
It adds a minimal of surface area for cooling unless drastic fluting is employed- back to weaker.
Our designs are focusing on extended competitions and engagements. A note that heavier barrels do have wider nodes, a concept that as of this date we agree with. The wider nodes make load development easier, a more forgiving rifle to shoot in a wider range of environments.
By weight structures are stronger than solids of their same weight. In our case significantly stiffer. We also have well north of more than 300% greater cooling surface. How much does it weigh? Our 300N barrel is 32 x 1.45D and weight 7.2lbs. We don't think about heat until north of 20 round strings. If it is cool outside... keep shooting. We test 25-50 round strings for group size, drift and SD variation.
The images shown are a ladder test from a .375CT. Ten grains in 1/2gr increments. Look at the groups: that is the 20rds with one adjustment to put the rifle on zero. This ladder test also represents round 8 through 28 through this barrel. This is quite common. Six more rounds were shot thru the barrel for prove out out to 2Kyds. Then it went to South Africa and was used to take 3rd and 4th place in K2K and K2M.
Please look at our simulations: you will see tests on barrels not seen before.

 

[DJ Fergus]

I'm deciding on a barrel contour for a hunting rifle build (300 PRC) and my research on barrels has brought to light the question of barrel whip.

We know that heavier barrels are supposed to be more accurate, but I wonder what can be done to mitigate the loss of accuracy as one goes with a lighter barrel.

I have a theory that fluting a barrel helps mitigate barrel whip. Any thoughts on this?

I also came across a strange contraption on Amazon: "LimbSaver Sharpshooter X-Ring Barrel Dampener." For $9.99, people are swearing that this thing is helping their groups considerably. Is this for real? Is it only helpful to light-weight barrels? Why would this be okay but having a floating barrel be so important?

I have a proof research sendero contour, 7mm rem mag, so far it's been the most accurate light weight rig I have shot. Bare rifle weight is 6lb 11 ounces. It's a .920 muzzle diameter. Supposed to be as stiff as a #6 contour all steel. IDK but it shoots. I don't doubt that the limbsaver tuner will help if tuned. I know guys running screw on tuners in matches and they work. 300 prc will be a beast in a lighter rifle. Be on top of your shooting tecnique to know what the rifle is really capable of.

 

[25WSM]

When you run a tuner like the Ezzel tuner or Harrell you are adding weight to the end of the barrel past the muzzle this makes the barrel swing more up and down. The more it swings up and down the slower this happens. The longer you keep the bullet coming out at the same time the barrel is at the peak or bottom you are in the node. Moving the tuner out or in changes this timing of your bullet exit with regards to the top or bottom of the swing. So as the temperature goes up outside your gun will shoot faster and it will change that timing of the bullet exit by moving your tuner it will bring that timing back.
If the temp goes up you need to move the tuner in to stay in tune. This is all very proven science.
Shep

 

[Mikecr]

Must be why those benchrest guys use skinny barrels. You know not of what you speak.

Then I guess nothing about my posted information relates to what 'benchrest guys' do or care about. Maybe I should have said that up front?

My assumption is that we're discussing potential improvements for HUNTING guns, in this Long Range HUNTING forum, for HUNTING barrels and cartridges, that will likely be used for single cold bore HUNTING shots, in the field, far from benches, bench rests, sighter/fouler shots, wind flags, and fixed range conditions.