Last September I install a new Shilen 5r 24” barrel with a Harrell tuner and using the Hopewell method shot over 600 rounds at 50 and 100 yards. I found two settings that were good with one that clearly giving the tightest 5 and 10 shot groups. Over the next few days I verified this setting at 50, 100, 200 and 300 yards and confirmed this setting to group exceptionally well. A few days later in my shop I got the idea of calculating the the recommended setting using the Purdy method for the 9th harmonic. I’m an engineer/ machinist and have the tools to accurately measure the settings. After carefully measuring the breech to the face of the tuner at this “tested best setting” the setting was .004” shorter than the Purdy solution. I then did the same using the 8th harmonic and that solution was .011” off of my next best actual setting. Maybe this is a coincidence but if I had used the Purdy method initially I believe that I would have come to the same conclusion using a lot fewer rounds and a lot less time.
- Thread starter Btrain
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What action? What's your setting now on the tuner? I've tried it ,top level br shooters have tried it and it doesn't work. It shouldn't have taken 600 rounds to tune, maybe a box at most. I know you guys are trying to find a quick and fast solution to tuning but there isn't any. If your system is able to be tuned it shouldn't take long to tune it. Keyword "system". All of it has to work together ignition, bedding, rest or whatever you shoot from.
Recently I replaced the Shilen with a 1 in 12 turn 21.5” PVA barrel. This time I set the tuner to the recommended Purdy length which correlated to 24 on my Harrell tuner. Tested at that setting at 50 and 100yards with excellent results. Average 5 shot groups at 50 yards = .219. Then started “twisting the tuner” and shot 300 rounds at a variety of incremental settings. Best setting I was able to find for both 50 and 100 yards turned out to be 27. I’ve been following the tuner thing ever since Bill Calfee introduced the idea and have read and tested hundred of articles (rimfire accuracy) including the articles from Varment Al on compensation. Ive never had a strong feeling about the best methods but can only report on my experience. For over a decade I used the Hopewell method but recently confirmed that the Prudy method seems valid based on reverse test conformation. Also Joe Chacon, Mr Harrell, the guys at KSS and the JPX tuner manufacture not to mention my local bench rest gunsmith recommends the Purdy RX. Action is a Rim X plus im a statistics guy and require significant data to confirm results thus the hundreds of rounds testing.
Let me tell you about the people you just listed. joe has never built a ara or psl winning gun. Harrell's haven't been in touch in rimfire for a very long time and would only recommend something they've heard. Kss lmao well they don't know how to tune either. I've seen plenty of guns come from them that couldn't shoot cause they were not tuned. Most of the top shooters I know and shoot with on a regular basis use a normal tuner set between 140 to 200. If you have to go out past that with a 24 inch barrel that's .900 straight you have other issues such as ignition or bedding. This is from 10+ years of top level br shooting. We've tried it and it didn't work. Have you ever looked at Tony Purdy scores? I've shot with him and he finished almost last at the indoor nationals a couple years back. If it actually worked shouldn't he have finished higher ? You guys can tell yourself whatever it is you need to make yourself feel better. I know for a fact it doesn't work
OK
You absolutely have been there. What do you mean by a "normal tuner" since from your experience, it wouldn't be a Harrels. I'm having a 24" Shilen ratchet fitted and would appreciate your recommendation as to tuner. No one seems to list them on the BR match winning equipment lists so I'd like to have an idea what match winners are using.
BTW
I was curious so I pulled some back ARA shoots since I found out that Joe competes. I found a 2016 ARA match, Joe shooting a 1022 build of his with his tuner. He came in third behind Les Williams and Jack Harper (who is second only to Joe Fredericks in most 2500's in ARA). One of Joes 1022's set a record at the Lapua test facility. He sponsors youth shooters as part of the ARBA association. His builds, including the one he was shooting at this time are set up with the Purdy method. He says it took 15 minutes to tune the rifle he used in this competition.
I was curious so I pulled some back ARA shoots since I found out that Joe competes. I found a 2016 ARA match, Joe shooting a 1022 build of his with his tuner. He came in third behind Les Williams and Jack Harper (who is second only to Joe Fredericks in most 2500's in ARA). One of Joes 1022's set a record at the Lapua test facility. He sponsors youth shooters as part of the ARBA association. His builds, including the one he was shooting at this time are set up with the Purdy method. He says it took 15 minutes to tune the rifle he used in this competition.
A normal Harrells tuner weighs 8 oz. and some change. They have a shaved version wich is liter not sure of the weight. Some tuners are heavier some are liter. Stiffer the barrel the liter the tuner needs to be. A 24" .900 straight contour a normal harrells will work fine. Joe's gun did hold a record at lapua not anymore and he himself or his guns have never won or placed in the top of any ara national match. Joe is a good guy but doesn't know what it takes to build winning guns. I use one of his stocks on one of my turbos love it. It's ok to believe whatever you want from whomever you want , but I do compete with a lot of the top shooters in the country and just about every one of them have a different way of tuning. We all have the same goal ,extract every single ounce of accuracy out of these guns that we can.
Don't know any of these dimensions you request. I don't use the prudy method so I've never measured them have no use for it. Tuning is simple finding killer ammo is the truly hardest part of this game
It would be interesting if you provided this information then we could compare your optimum setting with the Purdy method and determine if there is any correlation. I was also skeptical but did the reverse by finding the best setting using the Hopewell Method and then later did the math and found out the Purdy method was within a few click of that optimum Hopewell setting. Did this with two barrels. Seems more than coincidental but obviously you know much more than many of the so called experts that that believe this is a valid method.
Who are the so called experts?
Check out Starikshooting.com testimonials from OIympic medalists. The Tuner/tube was developed with inputs from Tony Purdy using the Purdy RX to determine length for specific barrel lengths. In a forum discussing this, he states that he is not a good shooter and is primarily involved in auto benchrest..
That's not experts
go look at what the top br shooters are using. It isn't the Tony Purdy tuning method that's for sure. Winning top level events in br are all that matter to me. When you find out how they tuned get back with meIn post #104 above you mentioned that with a 24” barrel a tuner setting of 140 to 200 for the best tune is typical. With my Harrell tuner the Purdy setting for a 24” barrel for the 9th harmonic is 153. Using the Hopewell method best setting was 157 with a Shilen 24” barrel.
I'm not sure you're doing the Purdy method properly . Make sure you're following the directions properly. Cause most if not all Purdys prescription requires some sort of extension past the end of the tuner. So I'm not sure how you ended up at 153 . Lmao read the directions
Cool I have pictures and thousands of rounds sent down range that says Purdy method doesn't work.
At 153, is your inner tube close tf flush with the outer? According to Tony's formula, is the outer tube is more than 1/4" beyond the inner tube, you need to multiply the inner tube diameter by .3 and subtract that to get a correct physical length. I have my barrels being shipped and have a CST tuner set up with a 1" bushing for the 24" shilen (bushing for barrels from 23.424" to 26.624" barrels} and have ordered a 1/2" bushing for my Green Mountain barrel which is just under 20" (bushing for barrels from 18.424" to 21.624"}.
I have no clue how these tuners are doing in competition but physically they look a lot like the tuner I got from Joe Chacon. All are set up for 9th harmonic tuning.
Looks like there are some folks that are of the opinion that the system works.
I have no clue how these tuners are doing in competition but physically they look a lot like the tuner I got from Joe Chacon. All are set up for 9th harmonic tuning.
Looks like there are some folks that are of the opinion that the system works.
and once again none of them are at the top of any leader boards either. The best shooting guns as of right now do not use the Purdy method I know cause I shoot with most of them. The guns that hold most records in br do not use his method either. You guys can keep telling yourself whatever it is that makes you feel good I don't care, but serious rimfire br shooters DO NOT use Purdy method they know it doesn't work.
Sam, you may not realize it, but Jason Thornhill sets his guns using the Purdy formula. You'd be hard pressed to find a better shooter at any match in the country.
That's not to say that anyone just sets them and leaves them, but there are those who start with it and don't move significant amounts from it. I would guess Jason has some exact criteria he uses, but there are nationals winning shooters using it. I should add, he does use a bloop tube and that uses a bit different calculation, but it is based on Tony's formula for the tube.
I won't say it works for everyone, but for all of the other things we try, it doesn't hurt to try it.
In my experience, what we see more of today is that we basically know a general "area" of tune on a Harrels for .900 barrels at 24". With most shooters now using taper lapped barrels, the idea of crowing at the "tight spot" isn't really a big issue. Cut an inch off the breech end, make it 24" and crown it. Most likely there will be a tune in the 135 +/-5 or the 200 +/-5 areas. YMMV.
I also guess I need to make the disclaimer that there are no absolutes in this game as we know, but it is a good starting point.
That's not to say that anyone just sets them and leaves them, but there are those who start with it and don't move significant amounts from it. I would guess Jason has some exact criteria he uses, but there are nationals winning shooters using it. I should add, he does use a bloop tube and that uses a bit different calculation, but it is based on Tony's formula for the tube.
I won't say it works for everyone, but for all of the other things we try, it doesn't hurt to try it.
In my experience, what we see more of today is that we basically know a general "area" of tune on a Harrels for .900 barrels at 24". With most shooters now using taper lapped barrels, the idea of crowing at the "tight spot" isn't really a big issue. Cut an inch off the breech end, make it 24" and crown it. Most likely there will be a tune in the 135 +/-5 or the 200 +/-5 areas. YMMV.
I also guess I need to make the disclaimer that there are no absolutes in this game as we know, but it is a good starting point.
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What is your method?
Lmao yeah he did good for a while and has ran out of his killer ammo and didn't do worth a crap at the indoor nats. That's one person to Jamie and doesn't represent my point. The majority of TOP shooters don't use it. Good for Jason when eley hand delivers you ammo you better win something.
Hey @Jadams, I'll give you some numbers to chew on.
Here's the rifle:
Here's how it shoots:
The barrel is exactly 26" long, and the end of the harrell tuner to the muzzle is 3.553"
I use my own method, which is loosely modeled on the hopewell method. I'm curious how close you find it to the purdy.
Here's the rifle:
Here's how it shoots:
The barrel is exactly 26" long, and the end of the harrell tuner to the muzzle is 3.553"
I use my own method, which is loosely modeled on the hopewell method. I'm curious how close you find it to the purdy.
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Turbo Shooter, I don’t believe you read my posts thoroughly. I used the Hopewell method confirming with hundreds of rounds at 50, 100 and 200 yards the best tuner setting. Several days later in my shop I thought it would be interesting to see how close my setting was to what the Purdy method recommended. I used the online Spreadsheet provided by Tony P. To calculate the setting and interestingly the recommended Purdy setting at the 9th harmonic was very close to the settings I found using the Hopewell method. Coincidence I thought. Maybe. I then installed a new PVA 12 twist barrel 21.5” and using the Hopewell method and several hundred rounds found what I believe to be the most accurate setting. Again later in my shop I confirmed that the calculated Purdy method was very close (9th harmonic) to the best settings found using the Hopewell method. To be clear I have never setup a rifle using the Purdue method. I’m an engineer for 33 years and have a natural curiosity over these types of things. I also know that if the correct variables are properly used and calculated that determining the best setting is entirely possible. I presented this issue to 4 other engineers that report to me and they believe that the Purdy method establishes the harmonic node precisely at the muzzle.
Yup, I have a weight ring. I forget its weight.
I've told you before I don't have those measurements cause they aren't important to me and truly don't care. Guys I've been in this game long enough to know better , like I said you can like and try whatever it is you want no matter if it is wrong. I talked with Tony when he first developed this method and tried it numerous times and could never get it to work and to get the correct length you had to have an extension or added weight and it wasn't no where even close to true tune. I can care less how you guys tune, I can just speak from over 10 yrs of high level br competition. Good luck
I didn't have them either. Took me all of 1.5 minutes, and that included going and getting the rifle from the vault and my caliper off the bench. lol
You say you don't care, but your participation would suggest otherwise. It wouldn't take you long to humor @Jadams if you wanted to be kind to him.
Lmao told him this two weeks ago you think im going to do it now. Good for you it didn't take any time for you to take measurements. I know certain methods of tuning are fake and the ones that aren't that's my participation.
Measuring my Harrell's, I now see where Turbo is coming from. Purdy is based on length. If I set my Harrell's at zero, the overall length is 3.82, minus the cutout, gives me an efffective tuner length of 2.6" since the inner tube is protruding. When I set the tuner to 150, I am still only measuring the inner tube and the overall length remains 3.82. This doesn't change until I go to where the outer tube is beyond the inner tube. According to the Purdy formula, this doesn't count until the outer tube is 1/4" beyond the inner. Looks like what we are dealing with is different designs. The CST and Chacon tuners do not have the inner tube setup like the Harrell's and are designed around the Purdy formula. Looks like everyone is right. The formula works with tuners of a specific design. I'm guessing that the Harrell's combines the tube with weight. The other ones are set up for tube with an option to add weight. I'm looking forward to playing with mine to see what I learn. JElrod has my barrels done and they will be here Monday.
You may want to google Purdy Perception Calculator and download the Spreadsheet. Then simply plug in your barrel length and desired harmonic and the result is displayed. I have never used this method to tune my rifle and don’t even claim it works but in the two instances I compared the settings I was surprised to see how close the settings were.
Sorry about the bold type. Turboshooter, there is a very famous book that I highly recommend you read. It was required reading in my high school and it changed my perspective. It’s called How to Win Friends and Influence People.
Have you not read what I've written more than once. I've done the calculations and they are nowhere even close to the same tune. I use a Harrells tuner with no weights or bloop tubes or slides just a normal harrells. I know exactly what it takes to win high level br matches , deep ass pockets!
Then please share your barrel length and overall length from breach to the face of the tuner. This will prove the Purdy method is flawed in your case. Data please not opinions.
So he wins like 3 or more nationals, PSL's, and multiple triple crowns and it was all ammo. Gotcha.
We can get you the best lot of ammo ever made and I am pretty confident you are still not winning outdoor nationals in St. Louis. I'm not either to be clear. Ammo is important, but it's not the sole factor in winning at that level.
After going through these again, I see my error. The info I saw mentioned adjustment for the inner tube. When I measure the tuner at 153, ignoring the inner tube I see it hits in the range. The inner tube was throwing me off. Does anyone know if the other design tuners like the Chacon PRX and SFP Pro X are performing well in competition?
Is this all at 50y competitions? Just curious. I read through this article - http://www.varmintal.com/a22lr.htm which makes a lot of sense to me.
Tuning for 50y will never hurt 100y as balancing the highs and lows to have the right POI at 50y will make 100y groupings tighter, but tuning for 200y, could cause 50y vertical dispersion where the slow rounds are too high at 50y because it was tuned to compensate for drop out to 200y.
Now looking at the harmonics and the curves, if you said all my ammo shoots from 1050-1080 then yes any ammo you go to will have the same tune setting.
But if you were tuning a 1030-1060, and a 1060-1090, the tune settings could be different. When talking about harmonic curves, I think there's a ballpark that is like good, which Purdy method probably throws you there, but there's no exact math for 1030-1060 vs 1060-1090. At the same time the Hopwell method seems to just work as well, and within 145 rounds you're done.
Tuning for 50y will never hurt 100y as balancing the highs and lows to have the right POI at 50y will make 100y groupings tighter, but tuning for 200y, could cause 50y vertical dispersion where the slow rounds are too high at 50y because it was tuned to compensate for drop out to 200y.
Now looking at the harmonics and the curves, if you said all my ammo shoots from 1050-1080 then yes any ammo you go to will have the same tune setting.
But if you were tuning a 1030-1060, and a 1060-1090, the tune settings could be different. When talking about harmonic curves, I think there's a ballpark that is like good, which Purdy method probably throws you there, but there's no exact math for 1030-1060 vs 1060-1090. At the same time the Hopwell method seems to just work as well, and within 145 rounds you're done.
I spent in excess of 1500 rounds lot testing across about 30 different lot numbers of R50, and an additional 500 rounds tuning, to get my rifles performance where I wanted it, and then another thousand to "prove" as best I could that it was going to stay there.
And I see you're running a Harrell's so you're a fan of the Hopewell method?
I want to get a locking screw for my tuner, so it looks like the Holeshot is the way to go for me.
You can lock a harrel very easily by taking the spring out and running the set screw right up to the ball.
I also like EC tuners, as they've proven to work quite well despite their simplicity and lack of adjustment range.
It took you that many rounds to tune? Lmfao holy shit that's way to many. If it took that long you've got other issues in your gun. Ie. Bedding, ignition ,or some other problem. Tuning isn't hard and doesn't take thousands of rounds to do it. I've tuned both of my guns within one box of ammo for both guns. Lol wow thousands of rounds
The way you talk down to everyone here every day… you must really be something with a rifle.It took you that many rounds to tune? Lmfao holy shit that's way to many. If it took that long you've got other issues in your gun. Ie. Bedding, ignition ,or some other problem. Tuning isn't hard and doesn't take thousands of rounds to do it. I've tuned both of my guns within one box of ammo for both guns. Lol wow thousands of rounds
Yup, really something. People must really look up to you.
There’s nothing at all wrong with my rifle.
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