Centerfire Barrel Tuners/ Muzzle Devices

[broncman]

Would love to here more about your formula but that info in that link makes you hopscotch around too much to peice it together!

One of the things that you have to learn in vibe analysis is about resonant frequencies. That is simple.... "ring" it like a tuning fork to excite the object. The destructive forces I have to fight in my line of work occur when the process creates vibration at the same frequencies as the resonant frequency of the machine frame....it beats itself to death! Then we start dampening, bracing etc to change the resonant frequency.

In our sport, I believe we have two issues we are addresing. First is the mass with the tuner controlling whip. Pretty good evidence of this working.

Second is the deadining of the rifles resonant frequencies. Bolt bounce, stiffer stocks, balsa stocks , deresonators, rubber etc.

As technology increases, low hanging fruit has allready been picked! We are now getting into "noise floor" aspects. The last few percent of attainable accuracy lost in this noise.

I believ the benchrest crowd will be the first to quantify things here as with slow fire long range, their us just so many variables that create this noise floor. That is why on say a Fclass rifle, rubber isolators on the tuners will be hard to notice much improvement over just say a regular tuner.

We also have the benchrest and slow fire lomg range

 

[BoydAllen]

Essentially, there is more noise to get lost in. Yes? Also, any shooting style that involves significant contact between shooter and rifle, is already benefiting from increased damping from that contact, but of course with that comes the requirement for shot to shot consistency of that contact. Recently I have been seeing more consistent results shooting a 6PPC more like a varmint rifle, holding, and shouldering it. The reason for the change was practical. I am shooting from a bench that is less steady than a concrete one, but this has been a bonus that was somewhat unexpected.

 

[PaklRat]

Hi All

I base my tuning on the harmonics of a given barrel length. By knowing what the length of the barrel is (from breach face to muzzle), and the harmonic you want to tune to, a new overall length of barrel and tuner can be determined to bring the barrel into tune.

At least on rimfire barrels, it has proven accurate in predicting the tune for a tuner alone, hand made tuners, slides, and the like, at times to within a couple thousandths of an inch.

It was recently used on a new build that set a new record at the Eley test facility in Texas.

For all I know, the higher pressures and velocities may not work with PRX, but I would really like to find out.

Part of what I would like to know is: If you have a CF rifle with a tuner, and you believe it to be in tune, would you be willing to share the barrel length (breach face to muzzle), the overall length of the barrel and tuner, and the diameter of the tuner opening. With this information I can see if it corresponds to a particular harmonic. I will gladly show the process, once I have an example to work with.

The CF rifle I shoot is a custom Smith-Corona 1903A3 (low serial number), that is minute of milk jug accurate out to 500Y with its original barrel and an old Redfield 6-18 and ammo it likes. She's a pretty old gal

It would be a gas if we can PRX to work with CF.

I look forward to working with you guys

Have a great day

Tony

 

[gunsandgunsmithing]

Tony, most cf tuners don't change the length between the breech and the end of the tuner. Most use a weight that moves on the tuner body behind the end of the tuner, or are simply a weight on threads behind the muzzle. Thy do work, but I'd be very interested in hearing from you about this and how the weight not changing the barrel length does what it does, vs. rf tuners that do. Your thoughts will be appreciated. Thanks very much. One or more of the tuners that I'm building for testing on cf rifles will be made where I can apply your tuning method.
I hope you are feeling better.--Mike Ezell

 

[memilanuk]

Mike,

Maybe I'm mis-understanding something... but they *do* change the distance - by virtue of the threads - when you adjust 'em. It might not be very much, but I think there is a change.

Monte

 

[gunsandgunsmithing]

Monte, here's a pic of a Lambert tuner. The body is of fixed length and the weights move on it.

 

[memilanuk]

Hello Mike,

I understand that... I think what Tony was referring to by the 'tuner' was the movable weight - kind of like when broncman was talking about his collar weight that clamps on the barrel. The 'body' that you're talking about is just a mounting system; it doesn't really do the 'tuning' per se, if my understanding is correct.

Monte

 

[gunsandgunsmithing]

Monte, maybe Tony will come back and give his own feedback, but I've got his formula and have used it with success on a rimfire rifle. That formula is all about the correct length of barrel and any attachments to it for proper tune. You physically change the overall length of the cantilevered beam(barrel plus attachments) to tune the gun. It can be done with an adjustable tuner or just a sleeve cut to the proper length and attached to the barrel. ---Mike

 

[broncman]

Finished my tuner today! I made a tight slip fit threaded bushing that is simply heated, and loctited to the barrel. No turning or modifying the barrel. Tuner weighs 8 oz. went to the range in horrible winds, set out some flags amd started tuning.

With less than half a turn I found my best group. Horrible conditioms but it shot very well. Tune I settled on put 4 in one hole in the teens but last hole put it in the high 2's . All grouos but one were still sub 1/2" groups.

Will post pics when I get home of the tuner. It utilizes o rings to keep it tight and absorb any vibrations from the thread to thread contact.

Real excited about this season. Now in my mind, I know it is not my rifle or load and will be all my fault for poor shooting!

This rifle shot very well before tuner, but even better afterwards. All my rifles will wear tuners from now on

 

[ridgeway]

Why do most tuners thread onto a 3/4"-xx thread opposed to a 5/8"-xx tenon? Is it because a 3/4" tenon would be more ridgid and be more responsive in tuner changes?

I plan on ordering 2 Harrells brakes....one to make a tuner brake and the other to fit so I can inner change easy. I usually use a 5/8"-32 on HV barrels and may go with a 3/4" tenon on a new barrel.

 

[BoydAllen]

I think that the thought is that in the case of button rifled barrels, that there is a risk of the bore being slightly enlarged if the barrel is cut down to the smaller diameter, and since competition barrels are most often larger than .750 at the muzzle, there is no need to have a smaller tuner tenon.

 

[PaklRat]

Hi All

I have a question for Broncman. Does you tuner extend past the muzzle or is it behind the muzzle. I am also interested in how you fixed the sleeve to the barrel. I would like to put a tuner on my rifle but do not want to modify the muzzle to attach it.

For my own knowledge, is there a "typical" barrel length and diameter used?

I also have an interest in cartridge design.

Personally, I am restricted to 30-06 and would be happy if you all have any pet loads that I might try. I don't have a true BR CF but it was built for target shooting versus hunting back in 1960.

I just got my RF rifle back with a new barrel and am looking forward to getting her tuned up for the coming season

Have a great day. Mike: I think they finally got my meds right, and I am starting to feel better. Still some vision problems, but the doctors think the effects will resolve themselves in short time,

Tony

 

[gunsandgunsmithing]

Tony, in short range cf br, because of weight restrictions in light varmint class, most tuners are seen in heavy varmint, where muzzles are around 1.000". Most tuners that I've seen are threaded. 900x32tpi. Common hv tapers are 1.250 down to 1.00(est) between 21-24the inches long. There is a mix of both beyond and behind the muzzle tuners. Both seem to work, in my experience, very similarly.

 

[broncman]

Tony,
Under the large diameter portion is another brass sleeve . Large diameter is threaded as well. The small diameter is not but has three internal grooves for three orings. The sleeve is brass with only about a thou maybe two oversize. I use the thicker green loctite made for cylindrical assemblies. If you use stainless on both parts, a loctite primer is required because the way it cures.

I would put the sleeve in the rear portion if I did it over again so I could remove the tuner. To further dampen vibes you can wrap the threads in a wrap of teflon tape.

 

[broncman]

This was my last 5 shot 100 yard group today. I started tuning flush and turned it forward. Suspect I could have went either direction and found a tune. I really believe if I had payed more attention to the wind, that would have been one hole.

If you use a sleeve put it on the rear portion of the tuner so you can remove it. I will redo mine.

 

[PaklRat]

Hi Broncman

How far in front of the muzzel is the end of the tuner?

It would be neat if you could tell me the barrel length and tuner opening diameter, in turn, I'll tell you a how close a tune I can figure with PRX

Tony

 

[broncman]

.028" in front. Barrel is 30" from breach to muzzle. Tuner diameter od is 1.475", id is 1.220". 2.375" long tuner. Barrel od is 1".

Tuner id is to the top of the threads not the root.

 

[PaklRat]

Thanks for the info

By PRX, the shortest muzzle to end tuner distance I could come up with is 1.51"(1.509"), and this is at the 17th harmonic.

I know of a couple of rifles that are shooting at this harmonic (granted they are rimfire) and they are shooting pretty well.

Any chance your tuner would go out that far,and a bigger chance that you would be willing to test it?

Have a great evening

Tony

 

[rickiesrevenge]

Is there a way to guesstimate how much a tuner should weigh compared to barrel length? I'd like to try one on my Benchrest XP-100's. I would think that it would have to be heavier to make a the difference as one on a longer barrel.

 

[Grimstod]

The concept of a runner sounds very cool. And not just for the looks but the results I am seeing posted.

I would like to build a gun with a 32in barrel that 1.25in contour.
Any idea how heavy a tuner you would need for something like that?
While reading about the Harvey’s Hot Rod Anschütz BR-50 it seams like a stiffer barrel needs a heavy runner.