Barrel Tuner and Accurizer

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by lorvan, Feb 5, 2006.

  1. lorvan

    lorvan Well-Known Member

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    Excuse my poor English.
    I have a Sauer 90 in 7 rem. mag. with a muzzle brake and a BF36 (http://www.ermesport.it/bf36.htm ) with a Svarowsky 6-24 scope, that I use for hunting deers shooting fron a hill to the opposite hill (300 - 800 yards ). For developing the right charge I calculate the time barrel with the quickload
    program and, in accord with the shock wave theory (http://www.the-long-family.com/OBT_paper.htm ) I adjust the load for optimum barrel time.
    But
    I would have best accurcy.Know someone how I cane tune my barrel and if the accurizer (http://rifle-accuracy.com/rifle.htm ) or similar work? Is possible build something like a tuner (http://www.benchrest.com/timeprecision/SUPERTUNER/supertuner.html ) for my barrel (I have a muzzlebrake and I cannot mount this tuner )..

    Thank You

    Lorenzo ( Florence Italy )
     

  2. Ballistic64

    Ballistic64 Well-Known Member

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    Tuners have been popular in the rimfire community for a long time but with centerfire,your getting into a new frontier.The main reason thier so popular with rimfire is the shooters dont have as much control over the ammunition as centerfire (reloadable cases).If you have access to Precision Magazine there has been some very good articles on the subject by Bill Calfee but the science of tuners is still largely unexplored in centerfire rifles,probably because thier not legal in centerfire benchrest comp.
    About 8-10 yrs ago I had a Winchester model 70 with the Boss (barrel tuner/muzzle brake in one)on it but Im pretty much convinced now that it was a marketing ploy by Browning after reading up on the subject somewhat.I believe the Boss attachment on the Model 70 wasnt near heavy enough to have much effect at all,especially with a centerfire round like the 264 Win Mag.I got fair accuracy out of it but the adjustment of the Boss didnt seem to make much difference.Itll probably be some time before some serious research is done with the centerfires.
     

  3. Jimm

    Jimm Writers Guild

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    Lorenzo, Hello

    No need to apologize for your english, you should read my italian /ubbthreads/images/graemlins/laugh.gif

    I personally do not know of anyone doing this for your rig . Maybe someone here that does will see this thread and reply.

    Meanwhile , welcome to the site , Jim B.
     
  4. Bart B

    Bart B Well-Known Member

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    I didn't know someone had a way to calculate barrel time. To me, it would be interesting as to how all the variables are managed. Here's some of the variables that determine how long it takes the bullet to go from case mouth to out the muzzle:

    Bore and groove diameter.
    Rifling land width.
    Flash hole diameter.
    Powder temperature.
    Powder burning characteristics.
    Primer intensity (varies with firing pin impact).
    Bullet jacket to bore resistance.
    Leade angle.

    And there's probably a few others, too. And of coures measuring barrel time would be the only proof the calculations were accurate.

    Regarding tuners on centerfire barrels; it can be done. Just get a split ring (shaft collar) of the right diameter and weight, then put it on the barrel and tighten the screws on each side of the two halves. You can move it a bit front to back to find out what happens.

    Rebarding the shock wave theory mentioned; I checked it out and it ain't quite reality. Rifle barrels have only one whip when fired; a US Olympic Team's mechanical engineer proved this years ago using accelerometers placed very close to the barrel to measure its movement when fired. And most rifle barrel's resonant (fudamental)frequency is well under 100 Hz and usally around 40 to 60 Hz; not in the hundreds the article mentioned. The high pitched "ping" a barrel makes when tapped produces vibrations so small they have no effect on accuracy. It's the single whip from recoil that makes the muzzle point up or down to different places when the bullet leaves to be significant. But the difference it makes in centerfire rifles is small 'cause as long as the bullet leaves at the same point in that whip for each shot, best accuracy is attained. With smallbore bullets taking three times as long to exit the barrel as centerfire bullets, timing that single barrel whip to get best accuracy is easily done with a moveable barrel weight.
     
  5. Buffalobob

    Buffalobob Writers Guild

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    Excuse my poor english, I am from Alabama

    This type of "tuning" is what those of us which shoot Ruger #1's have done for many years. The #1 has a forestock that is attached by a screw to a rod that comes out of the action and is paralell to the barrel and just under the barrel. The very tip of the forestock commonly is in contact with the barrel. By tightening or loosening the screw you can apply different amounts of upward pressure on the barrel. This will allow you to "tune' the #1 from 2.5 MOA groups to about 0.5 MOA groups.

    There is a commercial device sold for #1's that also works the same as the foreend screw.

    Hicks Accurizer


    While barrel contact devices will or may work to an extent they are very, very, very, sensitive to barrel temperature and as the barrel warms up, group size will grow begin to string badly.

    If you believe that your barrel may be helped by one of these devices you can test it out by simply getting your calipers out and finding different thickness of shims to insert under the barrel at the end of the forestock and go to the range and shoot and see if upward pressure helps. Sometimes it does and sometimes it doesn't.
     
  6. Bart B

    Bart B Well-Known Member

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    Tuners that apply pressure against the barrel have been around for years. They've typically been fitted in stock fore ends and applied pressure to the barrel at one or more points. And sometimes they work. But only when the pressure they apply is exactly the same for each shot. And that, in my opinion is their shortcomming.

    Smallbore target rifles use to have them. Remington's 40X and Winchester's 52 tried them. Folks would use a light wired through them to adjust the screws under the barrel to just touch it, then add the number of clicks for each to put pressure on the barrel at 4:30 and 7:30 positions that seemed to give best accuracy. Tests were usually done to determine the best setting slung up in a prone position. But the top shooters soon learned that the different tension put on the fore end in sitting, kneeling and standing positions changed the actual pressure on the barrel. So these "tuned" fore ends didn't shoot as consistantly accurate as a totally free floated barrel.

    The same barrel tuning devices were tried on centerfire target rifles....with the same results. In fact, the difference between slung up and not using a sling was quite a bit.

    Most folks don't realize how much a rifle stock's fore end bends from sling tension or just plain weight. One may get good results from a bench but I doubt the same tension on the fore end would happen in a field shooting position.
     
  7. LRHWAL

    LRHWAL Well-Known Member

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    Tuning with shaft collars is quite common for the Mini 14 shooters. The Mini has a very light barrle and even just fitting a brake can tighten groups dramatically (due to the added weight).

    The Mini shooters have tried the shaft collar idea with differing success. Do a search at http://www.perfectunion.com/vb/ (Perfect Union).

    Mini's are common for 3-gun competition in California - due to the laws whiuch restrict AR ownership, I'm told.

    One of the Mini 14 tuning guys also sells a system which they call a harmonic stabilizer http://www.accuracysystemsinc.com/ruger_mini_14_30.html

    I hope that's of some use to you.

    Wim
    RSA
     
  8. lorvan

    lorvan Well-Known Member

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    O.K, thanks to all.
    I'll try to make an accurizzer first for my remington vs sf 223 and lather, if it works, for my sauer 90 7 rem.mag.
    I went for hunting two years ago in Wayoming and in colorado with a friend of mine, an old vietnam sniper, Richard Sals. He used a browning bar in 7 remington magnum with a muzzle brake like a boss and shoot very well ( I used a remington 270 of an other friend, but I don't like this caliber ).
    Now I'll write to Cristopher Long (http://www.the-long-family.com/OBT_paper.htm ) because I don't understand why he do not consider the weight and the diameter of the barrel in his formulas, but only the lenght. I unfurtunately am not a musician, and spent a great part of my life studying neoplasm, but the same I think that a large barrel and a thin one of the same lenght cannot vibrate at the same frequncy..

    Lorenzo

    P.S. BuffaloBob, I escuse your English. Even in Italy we know that in alabama bray and speak only somethimes...:)
     
  9. BountyHunter

    BountyHunter Writers Guild

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  10. Buffalobob

    Buffalobob Writers Guild

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    As somebody mentioned up above- tuners are used on a lot of rimfire 22s

    The Delrin washer trick is used on 10-22s also. I have mine a part now polishing up all of the parts and I may install on of these little pressure tuners in the forestock.
     
  11. royinidaho

    royinidaho Writers Guild

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    [ QUOTE ]
    P.S. BuffaloBob, I escuse your English. Even in Italy we know that in alabama bray and speak only somethimes...:)

    [/ QUOTE ]
    [​IMG]

    buffalobob, he gotcha GOOD on that one. Sweet! And he's not even an LSU fan /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif

    Lorenzo, Benvenuto alla cartolina. Lo gradirete qui. (I hope that means what I think it means. /ubbthreads/images/graemlins/blush.gif /ubbthreads/images/graemlins/blush.gif)

    The 6mm BR artical shows a good concept. But remember it is shown being used on a very consistent and constant shooting platform. You will be in the field where conditions are not always the same. Nor will your stock be as rigid. Placement of the rest along the forearm may be critical.

    Please, let us know how it works for you.
     
  12. Buffalobob

    Buffalobob Writers Guild

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    When tuning a gun in Germany one should always be familiar with the expression

    "Ein mehr"

    When tuning a gun in Mexico one shoud say

    "Otra vez

    When tuning a gun in Alabama one should say

    "One more sip from the mason jar"

    The reason I don't know anything about tuning guns in Italian is they have no good beer. They clearly have only solved half of the world's problems by inventing pizza (or at least stealing it from the chinese) . But pizza and wine just don't get it.


    The reason I am working the Ruger 10-22 over is to shot in Ghog competition up im Mifflin so it will all be bench work this summer. I could spend a couple of hundred dollars for a bunch of competition parts but it is not any fun just to drive out a few pins and slap in new parts when you can spend hours and hours polishing and shaping everything. /ubbthreads/images/graemlins/grin.gif
     
  13. POP

    POP Well-Known Member

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  14. Buffalobob

    Buffalobob Writers Guild

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    Pop

    I still want to know how you get to be a "Junior" member. Are the benefits packages better than for a "regular " member?