Has your barrel tuner changed horizontal dispersion?
- Thread starter Tozguy
- Start date
Alex Wheeler
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Can't say that I have payed alot of attention to horizontal. I know i should, as I have a gun that will string horizontally. I can take 200 yard group in my dasher and make them go to 1'' vertical strings at the worst setting, at my best setting I can get consistent .3's at 200. (3 shots over flags). I have just started to play with them. I'm no expert and am not totally convinced yet that I know what I'm doing with it. I have got my best groups using it, but don't know how consistent they are over the long term.
Alex
Alex
Alex, if you have a rifle that will string horizontally but you can tune it to vertical strings or to small round .3'' groups, doesn't that imply that your tuner is changing horizontal dispersion as well as vertical?
Yours sounds exactly like the situation I am in, and with the same doubts about what I'm doing.
Yours sounds exactly like the situation I am in, and with the same doubts about what I'm doing.
yes it changes both i have ben using one for 3 years on many different guns and get the same results go to bostrom gun smith and see some of the testing results
Reed,
That's part of the reason why I am asking the question. It dawned on me that tuners might be doing more than theory suggests. In my case the tuner had more impact on horizontal than on vertical so it behooves me to find out if that is an exception to disregard or if it happens to others as well. If what Ron Hoehn says is true, wouldn't a tuner just change a big round group into a big horizontal group instead of a bughole?
That's part of the reason why I am asking the question. It dawned on me that tuners might be doing more than theory suggests. In my case the tuner had more impact on horizontal than on vertical so it behooves me to find out if that is an exception to disregard or if it happens to others as well. If what Ron Hoehn says is true, wouldn't a tuner just change a big round group into a big horizontal group instead of a bughole?
Alex Wheeler
Site $$ Sponsor
Tozguy,
The gun that has horizontal stringing, doesn't have a tuner. I just mentioned it because some people don't realize a gun can string horizontally just like it can vertically. The one with the tuner never showed a tendency to string horizontally. So I can't comment. It definitely seems to help tune out vertical.
The gun that has horizontal stringing, doesn't have a tuner. I just mentioned it because some people don't realize a gun can string horizontally just like it can vertically. The one with the tuner never showed a tendency to string horizontally. So I can't comment. It definitely seems to help tune out vertical.
STS
Silver $$ Contributor
Just a little thought stimulator for you gents. If your barrel happens to be oriented on the action with the curve of the bore in the lateral position, will the barrel give you more horizontal groups than a barrel that is indexed in a vertical orientation? I'll let the cat out of the bag and say that from my experimentation if a barrel is oriented with the curvature of the bore in the vertical orientation the barrel could be tuned to give pure vertical groups. If the barrel is oriented with the curve in the horizontal position the barrel would have a horizontal componet resulting in diagonal groups. I chambered the same barrels with the curve in one position and set the barrel back to bring the barrel to the other position and in each case saw the same vertical or diagonal pattern.
Alex, on the rifle with the tuner, what was the shape of the groups at 'bad' settings versus the shape of the group at a 'good' setting?
So far the observations I have made from my own limited experience are as follows: from one setting to another the group moves to a different location on the bull. From one setting to another the group may change shape (ie changes from a vertical group to a horizontal group or viceversa). From one setting to another the group widens or narrows on one axis or both. At one setting all 5 shots went in the same hole. It would be good to have a handle on whether this is normal or not. Not so much in theory but from observations others have made from twisting a tuner.
Although the article at Bostrom's website is well done I didn't notice anything specific about group shape and horizontal in particular.
STS are you saying that your experimental results did not not bear out the theory relating barrel indexing to tuner performance? That regardless of barrel indexing the tuner had the same impact on horizontal?
So far the observations I have made from my own limited experience are as follows: from one setting to another the group moves to a different location on the bull. From one setting to another the group may change shape (ie changes from a vertical group to a horizontal group or viceversa). From one setting to another the group widens or narrows on one axis or both. At one setting all 5 shots went in the same hole. It would be good to have a handle on whether this is normal or not. Not so much in theory but from observations others have made from twisting a tuner.
Although the article at Bostrom's website is well done I didn't notice anything specific about group shape and horizontal in particular.
STS are you saying that your experimental results did not not bear out the theory relating barrel indexing to tuner performance? That regardless of barrel indexing the tuner had the same impact on horizontal?
STS
Silver $$ Contributor
I'm not saying that at all. It seem that the tuner has a much easier time tuning the barrel if the barrel is indexed vertical so that the tuner doesn't have to fight the natural trend of horizontal movement of a horizontal indexed barrel. This is very interesting stuff to me and I have the ability to test some of these ideas. All it takes is a bit of time to do the machine work and retest the barreled action in my rail gun. It would not surprise me to have someone else have a test that shows a different result.
Alex Wheeler
Site $$ Sponsor
Tozguy,
The bad groups are vertical. The good groups are round. I have seen basically what you describe. I will need to go through my target book and find that target I did the test on to see if poa changed.
The bad groups are vertical. The good groups are round. I have seen basically what you describe. I will need to go through my target book and find that target I did the test on to see if poa changed.
My experience, not theory, after testing tuners on dozens of barrels is the same on all of them. That being, when the gun is completely out of tune(with the tuner), I get big round groups. Move the tuner slightly, and round groups get smaller to a point of near perfect tune within one or two small adjustments, but still with vertical. Next small adjustment takes out the vertical. That vertical is usually less than a bullet hole's worth. I go to a match with the tuner left where it was when I shot it last. This is almost always within 1 hashmark, one way or the other of proper tune when I begin to shoot. This is with a Shadetree tuner. So I tune the gun, if needed, on the warmup target at the beginning of the match, when conditions are typically best.
This all happens within 4-6 marks on the tuner...from completely out to completely in tune. All those threads are intimidating to many. You may find a "sweeter" spot somewhere along the tuner body, but the rest of this still applies to getting and keeping it in good tune. I typically start with the tuner rings near flush with the end of the tuner body. My experience is that if you start with a known good load, it'll be good within 4-6 marks on the tuner and have you in the middle of the tune window. From there, only small adjustments will be necessary to keep it in tune over a very wide span of temperatures, i.e., 40 degree swings. It's that simple.
Take this for exactly what it's worth, but it is based on a fairly good test sample. The only disclaimer I'll add is that most were 30 caliber HV barrels. I've had similar results on 6mm stuff. We're talking BR and PPC size cases.--Mike Ezell
This all happens within 4-6 marks on the tuner...from completely out to completely in tune. All those threads are intimidating to many. You may find a "sweeter" spot somewhere along the tuner body, but the rest of this still applies to getting and keeping it in good tune. I typically start with the tuner rings near flush with the end of the tuner body. My experience is that if you start with a known good load, it'll be good within 4-6 marks on the tuner and have you in the middle of the tune window. From there, only small adjustments will be necessary to keep it in tune over a very wide span of temperatures, i.e., 40 degree swings. It's that simple.
Take this for exactly what it's worth, but it is based on a fairly good test sample. The only disclaimer I'll add is that most were 30 caliber HV barrels. I've had similar results on 6mm stuff. We're talking BR and PPC size cases.--Mike Ezell
Alex Wheeler
Site $$ Sponsor
Mike, in your opinion, do you feel a gun is more or less sensitive with a turner? Say you have two guns. Both are tuned optimally. One is using a tuner. If there is a charge in conditions, temp, humidity, ext. Do you feel one will hold its tune better day in and day out?
Alex
Alex
zfastmalibu said:
I haven't done any analytical research with it but in a word, YES. It does seem clear to me that the tuner definitely "widens" the tune window. But even if it didn't, a simple "nudge" of the tuner is all it takes to get it back in.
For those that want to understand the why's and what for's of how a tuner works, please let me know when you have it figured out. But if it doesn't agree with what I've found to be true in use, I'll be very skeptical about theories.
Tozguy said:
I'd say it's as wide as it is tall...so to speak. What I've seen is BIG ROUND groups get smaller, first, leaving only a bit a vertical to tune out. So if you consider a big circle becoming a smaller circle, removing the horizontal first, then I guess so. When I say the groups start big and round, I mean basically round...but too big to fool with measuring to see if it's wider than tall, or even caring, when all I have to do to get the group to suck in is reach up and turn the tuner. Imagine a big "round" group in the low .4s..torn the tuner one mark, it becomes a basically round low .3. Turn it again, it becomes a .2-.25 with one or two coming out of the top. Turn it one more mark..or sometimes even less, and it becomes a nice round teen. That's what I see on a VERY regular basis. Keep turning the tuner the same direction and it'll open up just like it closed.
I have just read through this thread and am becoming interested in trying a tuner on one of my rifles. It would either be on a remington varmint contour in 243ai or an hv contour in 7 Dakota. Which model tuner would you guys recommend? Also, thank you all for posting such good information based on actual tests and not heresay or theories.
ergonsdad
Precision RAS Tuners
I have been working with a verity of tuners since the mid 90's on a wide variety of rifles from precision long rang target rifles to hunting rifles. The tuners have included the Browning Boss system and many others and most recently the Rifle Accuracy Systems RAS system.
Recently we published an article in the June 2012 Precision Shooting Magazine reporting some of the results. Eric Bostrom ,www.bostromgunsmithing.com, has a excellent set of instructions explaining how to tune a RAS system with some pictures showing how the groups change from vertical to horizontal to a small round group. Look at the pictures on page 6. He also has a link to the PS article.
Typically groups will change in size and from vertical to horizontal until the optimum small group is obtained. With the RAS system small changes can make a big difference. With one 360 degree rotation there will be a number of maximum and minimum groups. Pick the tuner location that gives the smallest group and explore the tuner setting on both sides of that location. Sometimes as little as 5 degrees or less will produce a significant change in group sizes.
Tuners can make any group better. On a precision rifle it can get to the point where we are measuring the shooters skill more than the rifle.
For more details go to Eric's site and down load the Instructions and the PS articles.
Recently we published an article in the June 2012 Precision Shooting Magazine reporting some of the results. Eric Bostrom ,www.bostromgunsmithing.com, has a excellent set of instructions explaining how to tune a RAS system with some pictures showing how the groups change from vertical to horizontal to a small round group. Look at the pictures on page 6. He also has a link to the PS article.
Typically groups will change in size and from vertical to horizontal until the optimum small group is obtained. With the RAS system small changes can make a big difference. With one 360 degree rotation there will be a number of maximum and minimum groups. Pick the tuner location that gives the smallest group and explore the tuner setting on both sides of that location. Sometimes as little as 5 degrees or less will produce a significant change in group sizes.
Tuners can make any group better. On a precision rifle it can get to the point where we are measuring the shooters skill more than the rifle.
For more details go to Eric's site and down load the Instructions and the PS articles.
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