Barrel tuners. Good or a waste of time?

[gunsandgunsmithing]

Hi folks.

A simple question. I was wondering how many shooters who shoot say 600yds to 1000yds in benchrest competitions use a barrel tuner in the USA.

As the States will have far more competitive shooters that we have here in the UK I was after a general idea of how popular (or not) they are in competition use.

Thanks and have a Happy Thanksgiving and good shooting to All.

Les

Les, I absolutely, positively, beyond any doubt, believe that proper use of tuners makes them a game changer...and they're super easy to use. You just have to weed through the chaff of misinformation. We've come a long way in the last few years. I'm always happy to talk tuners. You can reach me on here and we can talk if you want.

I appreciate all the positive reviews on here from everyone.
I am thankful!

Happy Thanksgiving!

 

[gunsandgunsmithing]

Oh..fwiw, I've been testing a tuner specific barrel contour that allows us to put weight where we need it better than a typical hv contour, while making the barrel more responsive to a tuner. I've been very happy with the one barrel, so far. Another is on the way. Lv will be a little more difficult and I'm not sure if we're there yet in terms of shooters accepting something that different just yet. As more and more shooters migrate to proper tuner use, I think more people will see their value as more important than staying with the same barrel profiles that we've become so accustomed to. As a group, we are slow to accept change at times.

 

[Crow]

I presume you nudge the tuner only if the temperature changes. And if it that is correct then which way if the temp goes cooler (in or out?)
Thanks

I've only had my Ezell tuner a short time, but Mike shared this rule of thumb with me: Down and Out.

A friend and I were discussing that piece of advice, and figured it might be because as the temperature drops, the length of a barrel would become ever so slightly shorter, and moving the tuner out slightly would compensate for that. Just a theory...

 

[gunsandgunsmithing]

I've only had my Ezell tuner a short time, but Mike shared this rule of thumb with me: Down and Out.

A friend and I were discussing that piece of advice, and figured it might be because as the temperature drops, the length of a barrel would become ever so slightly shorter, and moving the tuner out slightly would compensate for that. Just a theory...

Lots of things going on at once Steve but the reason is that as temps go up, powder creates more velocity..so the bullet reaches the muzzle sooner.
Moving the tuner in toward the receiver raises the frequency of vibration, hence speeding the barrel up to time optimal muzzle position with the earlier bullet exit of the now faster bullet.
Moving the tuner out does the opposite...down and out.--Mike

 

[Crow]

Thanks Mike - it makes a lot more sense that the velocity difference caused by a change in temperature would have a greater influence on barrel time than any temperature-induced expansion/contraction of the barrel would.

 

[geordiesniper]

Lots of things going on at once Steve but the reason is that as temps go up, powder creates more velocity..so the bullet reaches the muzzle sooner.
Moving the tuner in toward the receiver raises the frequency of vibration, hence speeding the barrel up to time optimal muzzle position with the earlier bullet exit of the now faster bullet.
Moving the tuner out does the opposite...down and out.--Mike

Hi Mike, now that is the answer I wanted to my question. Thanks for the explanation. My heavy gun has a tuner fitted so I now understand how to use it if necessary.
Best wishes, Les

 

[normmatzen]

I use tuners on both my light and heavy long range bench rest guns. I also use the heavy gun for F Class. Wouldn't go back!
Both my tuners are made by my friend in Australia.

 

[JMayo]

I've not seen one on any CF at any of the matches I've been to in the last 2 years.
They are on all the 22 match rifles.

 

[gunsandgunsmithing]

I've not seen one on any CF at any of the matches I've been to in the last 2 years.
They are on all the 22 match rifles.

You will! Seriously, they are on a good portion...maybe half or more, of cf br rifles around the country....and growing in popularity all the time.

 

[Dusty Stevens]

Its been many years since ive been to a match and not seen a tuner- long and short range

 

[gunsandgunsmithing]

Its been many years since ive been to a match and not seen a tuner- long and short range

Me too Dusty. I really can't remember the last time there were no guns at a match without one. Had to be around 2007 for me...maybe before that.

 

[Bart B.]

I've seen good results with scope rings clamped on the muzzle end with weights clamped in their bottoms. All that is needed is to change the frequency the barrels front several inches vibrates at.

By the way, it was a British man who first documented positive compensation on their 303's over a century ago.

https://archive.org/details/philtrans05900167

Newer tests....

http://www.geoffrey-kolbe.com/articles/rimfire_accuracy/tuning_a_barrel.htm

 

[Bart B.]

And for what its worth, I think the popular Optimum Barrel Time "tuning" theory is the furthest from reality. The frequency the muzzle diameter cycles at in the OBT theory is far from what good mechanical engineering software calculates it to be.

And it doesn't compensate for bullet's muzzle velocity spread and departure angle to the line of sight.

 

[normmatzen]

Bart,
You are close, but no cigar.
Tuning the load (OBT) for best velocity ES actually tunes the longitudinal resonance and tightens Mv. I do 1% increments of load and one five shot group per load done in round robin style. Then I plot the Es vs load on Excel and do a curve fit for optimum load.
THEN, I remove the chrono and shoot 3 shot groups at distance and tune my tuner in 1/20th turn increments to find least vertical spread. This
tunes the cantilever resonance of the barrel. I do an Excel plot of this data and curve fit for best tune as well.

Do the tune over different temps and end up with data to adjust tune as a function of temp.

 

[gunsandgunsmithing]

And for what its worth, I think the popular Optimum Barrel Time "tuning" theory is the furthest from reality. The frequency the muzzle diameter cycles at in the OBT theory is far from what good mechanical engineering software calculates it to be.

And it doesn't compensate for bullet's muzzle velocity spread and departure angle to the line of sight.

I'm with you Bart. If it works for ya, go for it but there's just not much physical support for obt and what really happens when a gun is fired. Reminds me of the PRX tuning method. It has a fair following in rim fire that mostly claim it to "get you close".

I say, with a tuner, you're always "close" with or without prx. Lots of people move a tuner too far and skip over the sweet spots...Yes, SPOTS.
Jmho.

 

[Bart B.]

Tuning the load (OBT) for best velocity ES actually tunes the longitudinal resonance and tightens Mv.

You're changing the frequency the shock wave makes round trips (muzzle to breech) in the barrel?

What's longitudinal resonance?

I don't think a given profile barrel can have its resonant and several harmonic frequencies, nor the speed of sound in it, change by tuning a load.

 

[normmatzen]

When the firing pin strikes the primer, and the charge goes off, a shock wave travels longitudinally toward the muzzle and when it reaches the muzzle it turns around and goes back but out of phase. This time is a direct function of the speed of sound in steel (the fastest propagating media in nature) and that sets the "node". When selecting the correct node multiplier, the barrel will force the muzzle velocity to group around a node for better Mv Es.
Then, you have to deal with the cantilever resonance where the barrel whips. The right position of the tuner weight will maintain the same angle of departure with a slight variation of mV.

 

[alinwa]

.................... (the fastest propagating media in nature) .

well...... except for glass, and granite and about a thousand other "mediums in nature" which are all faster.......altho in which reality steel barrels are "naturally occurring" I'm fuzzy.......


I ain't buyin' one drop of this "I can quantify resonance in solids" stuff..... better just stick with things that are slow enough ya's kin' hear 'em doppler I always say...

 

[Bart B.]

When selecting the correct node multiplier, the barrel will force the muzzle velocity to group around a node for better Mv Es.

you lost me.

What's a node multiplier and the speed of sound in barrel steel?

Then, you have to deal with the cantilever resonance where the barrel whips. The right position of the tuner weight will maintain the same angle of departure with a slight variation of mV.

How is that possible when any spread of muzzle velocity causes a different bullet departure angle relative to the line of sight?

Note the cantilever harmonic frequency tuners work in is several times higher than the barrel's resonant frequency that's only several dozen cycles per second

 

[jimmymac]

You guys make my head hurt.