Centerfire Barrel Tuners/ Muzzle Devices

[bigbore]

Good to see some humour on here

We affectionately call our tuner's "big knobs"

A mate has a large highly polished brass tuner that we call "Gold Member"

Some of the Aussie fun we got asked about alot at Raton, NM

Cam

 

[johara1]

It is funny the i only saw one tuner on a 1000 yd. bench rest rifle last year and this year i saw none……. jim

 

[broncman]

From vibration analysis 101.....
Mass, stiffness, dampening.... The three basics for changing vibration characteristics.

Rubber coatings (put a wrap of tape on the forks of a tuning fork and see what happens), braces at non node points (barrel buttons in stock fore arms), heavier barrels or carbon fiber wrapped barrels for weight and/or stiffness.

Some of the guys doing the balsa wood/carbon fiber laminate stocks are very forward thinking in the dampening category with the balsa!

Would love to urethane coat a barrel if it was not so ugly. It would "deaden" the resonant frequency tremendously.

 

[Medic505]

I shoot some benchrest at local matches where we have a production class. Everything on the rifle must be factory. My factory rifle of choice is a Savage LRPV in .22-250. I purchased one of the Limb Savers for the heck of it and I slid that thing all over the barrel and never did see any difference. This rifle shoots very well BTW. The first match I shot with it, I happened to win. I was the only shooter using a tuner at the time. Funny part about this is, next month I was amazed how many tuners showed up at the range. Can you say monkey see, monkey do? LOL

 

[gunsandgunsmithing]

I shoot some benchrest at local matches where we have a production class. Everything on the rifle must be factory. My factory rifle of choice is a Savage LRPV in .22-250. I purchased one of the Limb Savers for the heck of it and I slid that thing all over the barrel and never did see any difference. This rifle shoots very well BTW. The first match I shot with it, I happened to win. I was the only shooter using a tuner at the time. Funny part about this is, next month I was amazed how many tuners showed up at the range. Can you say monkey see, monkey do? LOL

You're welcome to come to my shop sometime. I'm positive that I can convince you that a tuner will change the group size and shape in under 5 minutes. You do the shooting, I'll move the tuner.

 

[Medic505]

I'd love to come to your shop, and just might do that one of these days. Anytime I can learn something that might improve my shooting, I'm all ears. I have one of Erik's tuners on a new TR rifle that is getting stocked by Doan Trevor as I write this. I can't wait to get my hands on it and get a load worked up for Phoenix. I know that tuners work, it just so happened that the limb saver made no difference. Maybe I should have tried two of them on that rifle, you never know. BTW that chunk of rubber can still be found on that Savage. It's my good luck mo-jo.

 

[swed6.5]

This has been a great read.from a off the wall stand point almost all harmonic ballancers are sleeved with a rubber insulator. good ones set up for racing are fluid filled. has anyone tryed this. I have used 2 tuners and have found good results. but lately have just used a good tuned barrel and found more time required to get what i wanted but have found to be more rewarding knowing i tuned my rifle not a sleeve or weight. not diss,n them just walked away.

 

[gunsandgunsmithing]

I'd love to come to your shop, and just might do that one of these days. Anytime I can learn something that might improve my shooting, I'm all ears. I have one of Erik's tuners on a new TR rifle that is getting stocked by Doan Trevor as I write this. I can't wait to get my hands on it and get a load worked up for Phoenix. I know that tuners work, it just so happened that the limb saver made no difference. Maybe I should have tried two of them on that rifle, you never know. BTW that chunk of rubber can still be found on that Savage. It's my good luck mo-jo.

I'd be happy to have a fellow shooter come by. I don't know how much you'll learn, but come on anyway.
I think you'll learn on your own, very fast, that tuners work and that it only takes small adjustments to see it. That's where many people get sideways with tuners, is by making big swings with adjustments, when as little as a 1/2 mark can make a visible difference on the target. The amount of movement has a lot to do with the tuner design and weight, but none that I've ever seen needed to be moved more than about an 1/8th of a turn to see BIG differences, and most not nearly that much.--Mike

 

[gunsandgunsmithing]

This has been a great read.from a off the wall stand point almost all harmonic ballancers are sleeved with a rubber insulator. good ones set up for racing are fluid filled. has anyone tryed this. I have used 2 tuners and have found good results. but lately have just used a good tuned barrel and found more time required to get what i wanted but have found to be more rewarding knowing i tuned my rifle not a sleeve or weight. not diss,n them just walked away.

You poor guy..I feel sorry for you. You're thinking like me! [SIZE=78%] That's exactly how I came to where I am with a new tuner design. I have some prototypes in production right now. They will utilize mass as well as a dampening material to dampen vibration...not liquid nor rubber, though. I should have some testing done in a couple of weeks.--Mike Ezell[/SIZE]

 

[broncman]

Years ago, I made one with hollow cavity and lead shot..kinda like a deadblow. Never saw any positive results.

 

[gunsandgunsmithing]

It won't be lead shot either, but I'll keep that in mind. That's what testing is for. It's only money...I have some unique material that is a very efficient vibration dampener that I'm going to use first. At worst, it'll be a tuner that works like most, deadening by mass. At best, it'll be a significant improvement over what most are. I hope for the latter. I've seen a boring bar made of heavy metal that made a huge difference in it's propensity for chatter. It's soft and dense.That stuff is about $6-$70 per inch, 1 in od. Thanks!--Mike

 

[Keith Glasscock]

It is funny the i only saw one tuner on a 1000 yd. bench rest rifle last year and this year i saw none……. jim

It might be that there is a difference in objective between the two games heavily represented in this thread - benchrest and slow-fire score. Perhaps, the tuner is more helpful to the slow-fire competitors who cannot always choose when they are going to fire shot #2, 3, 4, 15, or 20. Maybe it is because slow-fire shooters don't get to clean between relays, nor time to load at the range - we have to score or pull targets.

A question for you: Do you load at the range? When you do load, do you cookie-cutter the load, or adjust it for each relay as needed?

 

[gunsandgunsmithing]

I pre-load with a known good load and use the tuner to "keep" it a good load as the day goes by. This is for short range BR, but there is time btween relays to load in BR.

 

[FergusBailey]

If we are looking at match results alone, I agree, but I have shooting experience that has convinced me that there are advantages to using rubber as part of a tuner, that are not directly related to the overall principle of a simple adjustable weight.

Boyd

I hear what you are saying. However I think results from high-level competition (ie worlds, nationals, super shoot) give a pretty good indicator of what works. At this stage there doesn't seem to be a clear winner for tuner design - there's probably still more experimenting required before we distill the formula down to that point.

Right now we only know that tuners are appearing on more and more rifles, and appear to be beneficial in multiple different formats. I wont try to predict what configuration works best. But will predict that tuners have yet to reach their peak in the precision shooting sports - I expect we will see them on the vast majority of rifles at a BR match in the not too distant future.

I will be looking forward to hearing how your experimentation goes.

 

[PaklRat]

Good Morning All

My name is Tony Purdy. A while back I came up with a process for determining the tune for RF benchrest rifles called the Purdy Prescription. It has proven successful in predicting the proper tune for the barrels on these rifles.

What I am interested in, is if this same process will work with CF rifles. I don't have the equipment necessary to do the testing myself, so I was hoping some of you would be willing to help me look into this.

I shot a little short range (200-300 yard) F Class a few years back with an old rifle my dad had built back in 1960. I have done some handloading, but am by no means skilled.

Any help would be greatly appreciated

Have a great day

Tony Purdy

 

[broncman]

???

What was the process?

 

[Erik Cortina]

???

What was the process?

I don't know, but it sounds Purdy interesting.

 

[Greyfox]

Gene Beggs has probably done as much research as anyone on barrel tuners and centerfire rifles. Gene says (and I have found it to be true) that the tune will change as the temperature changes throughout the day. With a LV barrel he places the changes at about every 5º. While shims would probably work to one degree or another, it would be awkward to change shims that often. All of my rifles, with one possible exception, need to have the tuners adjusted about every 5-10º of temp change. The exception is a straight taper barrel that needs to be adjusted slightly less. If you come preloaded, as Mike Ezell does, it's a fairly straight forward process to make small adjustments as the day heats up.

One other thing. The question was asked about whether a miss from tune was different than a miss from a wind flag misread. When you are out of tune, you will not get true, consistent readings from wind flags.

My opinions are worth what they cost you,
Rick

 

[BoydAllen]

FWIW, my experience is that vibration damping is a issue that can either be combined with a tuner, or dealt with as a separate issue, but it is important. Back when Jim Borden made stocks, his design was different than others that were are are still available, and he was confident that it was better damped. I have a friend who has experience with "fiberglass" stocks from all of the current manufacturers that also had one of Jim's, and although it was a little heavier, he said that it was his opinion, that it shot a little better. I give that more as background, since they are no no longer being made. Jump forward to the balsa, redwood, or cedar and carbon fiber stocks of today, and within that discussion their having better vibration damping will usually be mentioned. For those of us that are not in the market for such an expensive option, I am of the opinion that there are other alternatives that can be explored. One of these being the Sims Deresonator, which I believe does not see more use because of three major reasons. Top shooters have gone to stocks that do not see as much advantage from additional damping (the if Tony isn't usin gone factor). Deresonators are butt ugly. (This has more influence than most would admit.) and they are cheap, which is enough to convince some that they cannot be worth much functionally. In any case, whether it is incorporated in a tuner, or dealt with separately as a separate issue, I believe that the effect of improving vibration damping is significant, and would point to the whole discussion about the effects of bags being too hard, which I believe to be directly related as some degree of proof of its importance.

 

[Tim Singleton]

Purdy prx


http://www.rimfireaccuracy.com/Forums/showthread.php/4210-The-Purdy-Prescription