Barrel Tuning Tests Part 2 AND Part 3 (prototype)

[RawHP]

Barrel Tuning Tests Part 2

After tinkering with the Limbsaver X-ring barrel de-resonator (reviewed earlier http://www.calguns.net/calgunforum/s....php?t=1060148My test gunParts:Stage 1:Stage 2:Results:Conclusion: Behind-the-muzzle tuning does have a noticeable effect on groups. That method of tuning appears to be sensitive to variations ammo and conditions, although it may have been possible to fine tune to remove some of those effects. Weight seems to have less influence than position of the tuning device.

Next steps:

[Dano3467]

Interesting post OP, looking forward to your next step.

[kel-tec-innovations]

Interesting findings.

[LynnJr]

Go to World Wide Accuracy and read everything you can from Bill Calfee. Nobody there shoots cheap ammo because of the wide velocity variations it produces and how much variation a tuner can handle.
There is no better source for rimfire accuracy than Bill Calfee.

[covingtonhouse]

Are you weighing your rounds? Any light or heavy rounds will affect your groups also. How much ammo testing have you done with match ammo types? I've found that the more expensive stuff is more accurate, but my wallet doesn't seem to like it as much. Ammo that shoots lights out at 50yds may not perform as well as another at 100yds.

[choprzrul]

quit messing around: http://harrellsprec.com/index.php/products/tuner-brakes

I have 2 of their tactica brakes. 3 powder weight tests and I ended up yesterday with a 5 shot 100yd group measuring .663. Pics are available later, I'm on my phone now....

You can tune your loads or you can tune your barrel......or both ;-)

[RawHP]

quit messing around: http://harrellsprec.com/index.php/products/tuner-brakes

I have 2 of their tactica brakes. 3 powder weight tests and I ended up yesterday with a 5 shot 100yd group measuring .663. Pics are available later, I'm on my phone now....

You can tune your loads or you can tune your barrel......or both ;-)

Thanks. They look cool and I'm sure they work, but I like the tinkering aspect, and there's only so much I'm willing to spend on ammo or parts on a 10/22. If I ever build a benchrest bolt action, then I can see buying a tuner, but for now, I enjoy testing the theories.

I also do my own gunsmithing and enjoy it, and will always opt for buying a new tool to do things myself than send things out or buying an off the shelf part. Same with handloading. I only buy ammo for defense, but everything else I shoot are loads I develop. Of course, with rimfire, you can't fine tune loads, which is why I'm playing around with the various tuning theories. I'm sure there are other gunners like me that enjoy tinkering though.

[RawHP]

Go to World Wide Accuracy and read everything you can from Bill Calfee. Nobody there shoots cheap ammo because of the wide velocity variations it produces and how much variation a tuner can handle.
There is no better source for rimfire accuracy than Bill Calfee.

His theory on stopping the muzzle is what is driving my tinkering around this this stuff. What is attractive about his theory is that once you find the right combination to stop the muzzle correctly, you never need to make other adjustments. This makes me think that even though tuners are really finely adjustable, there's only one setting that truly stops the muzzle, which means as long as you have a way to make very small adjustment to the location of the weight in front of the muzzle, you can stop it, whether you buy a tuner or if you build one.

My plan is to build something simple, but have a fixed point that I can use calipers to make those precise adjustments against. Off the shelf tuners do this by very fine threads used to move the weight forward and back. I should have all of the parts to build my prototype by early next week, and maybe have it ready to test by the long weekend.

[joe47]

All the tuners in the world are not going to make cheap ammo shoot good. The better the ammo the more accuracy you will get. I too have tried the "O" rings. Using them, the better ammo I used the better the targets were.

I agree with a poster above, Bill Calfee has a great book "The art of rimfire accuracy" that anyone interested in better accuracy out of a .22 needs to get.

Depending on the type of rimfire you are using, different methods of pillaring and bedding may help. It did with my CZ's. In fact my best shooter in bedded from the trigger area, all the way to the end of the stock, including the barrel. Some need to have the barrel free floating to shoot good. A lot of trial and error is need sometimes.

[RawHP]

All the tuners in the world are not going to make cheap ammo shoot good. The better the ammo the more accuracy you will get.

I agree that better ammo will shoot better simply due to consistency. But, consistency will only get you so far. I can make an extremely consistent batch of handloads and weigh measure all of the projectiles, brass, and use a powder trickler to make the charges perfectly consistent, but accuracy in the firearm will still depend on the combination of bullet weight, velocity, and powder burn rate (projectile acceleration) that works best in the particular firearm. I think the tuner is working on altering the firearm to work with the combination of projectile and projectile velocity, and better ammo is really dealing with the consistency aspect.

That's why people who shoot centerfire don't mess with tuners, because it's way easier to adjust the charges and projectile combinations than it is to tune the barrel or find the exact right factory load.

[LynnJr]

The smarter guys shooting centerfires are using tuners. Bill Calfee has two books out with the same title and if you turn to the third page of his first book I am the same Lynn.
The last three or four super shoots were dominated by tuners and the smallest group ever fired in centerfire competition was shot with a tuner.
Look up positive compensation by Dr Geofrey Kolbe as he gives a good explanation of how much velocity spread can be tuned out.
If the pictures shows up the gun with the wood stock is the standard Harrels/Hoehn tuner and the blue gun which won the 2010 NBRSA 1000 Yard National Championship is using a 6 ounce Stiller tuner in 6 Dasher. The green 6 Dasher is wearing a Harrels/Hoehn tuner as well but it has the additional weights added to it. Once the tuner is set it never gets adjusted.

[AceGirlsHusband]

The smarter guys shooting centerfires are using tuners. Bill Calfee has two books out with the same title and if you turn to the third page of his first book I am the same Lynn...

I would venture to say NO one who shoots bench rest rimfire shoots a naked bbl anymore: and haven't for many years. Tuners definitely work. The great disagreement among shooters is WHY they work. I like Calfee's theory of "stopped muzzle" and "parallel node" because its simple. Then you get a whole bunch of people who are into more exotic explanations such as positive compensation and it gets to be a headache.

I use a Harrell tuner on my BR gun with a five ounce weight and it makes one heck of a difference in my consistency (not to mention shrinking groups to .1" from .2 or so). Whether you use a Von Ahrens, a Harrell, a bloop tube, a slide or a combination, it takes a lot of trial to find the right combination.

For anyone starting out tuning their rimfire, I would suggest taking a look at Rimfire Central and search out the Purdy Formula. It is invaluable for getting a tune close right out of the box.

(*And just a side note, WWA is no more. It is now CYankeeAccuracy - and I believe BC is now chief owner and moderator. It probably helps keep Jerry Stiller of his back on that forum...

[AceGirlsHusband]

...)

[RawHP]

The smarter guys shooting centerfires are using tuners. Bill Calfee has two books out with the same title and if you turn to the third page of his first book I am the same Lynn.
The last three or four super shoots were dominated by tuners and the smallest group ever fired in centerfire competition was shot with a tuner.
Look up positive compensation by Dr Geofrey Kolbe as he gives a good explanation of how much velocity spread can be tuned out.
If the pictures shows up the gun with the wood stock is the standard Harrels/Hoehn tuner and the blue gun which won the 2010 NBRSA 1000 Yard National Championship is using a 6 ounce Stiller tuner in 6 Dasher. The green 6 Dasher is wearing a Harrels/Hoehn tuner as well but it has the additional weights added to it. Once the tuner is set it never gets adjusted.

Thanks. Yup, makes sense that if they work with rimfires, they would also work with centerfire. I guess maybe the reason it took longer to be adapted by centerfire shooters is because they have the ability to control more factors (ammo) than with rimfire.

[RawHP]

I would venture to say NO one who shoots bench rest rimfire shoots a naked bbl anymore: and haven't for many years. Tuners definitely work. The great disagreement among shooters is WHY they work. I like Calfee's theory of "stopped muzzle" and "parallel node" because its simple. Then you get a whole bunch of people who are into more exotic explanations such as positive compensation and it gets to be a headache.

I use a Harrell tuner on my BR gun with a five ounce weight and it makes one heck of a difference in my consistency (not to mention shrinking groups to .1" from .2 or so). Whether you use a Von Ahrens, a Harrell, a bloop tube, a slide or a combination, it takes a lot of trial to find the right combination.

For anyone starting out tuning their rimfire, I would suggest taking a look at Rimfire Central and search out the Purdy Formula. It is invaluable for getting a tune close right out of the box.

(*And just a side note, WWA is no more. It is now CYankeeAccuracy - and I believe BC is now chief owner and moderator. It probably helps keep Jerry Stiller of his back on that forum...

Thanks for pointing me to the formula! I read the sticky, and it's taking me a while to absorb it, but then I downloaded the spreadsheet, which is making it a little clearer. It will save a lot of ammo by getting to a good starting point to adjust from.