What do those 4 nodes represent, or do, to bullet positions on target?
Barrel tuners. Good or a waste of time?
- Thread starter geordiesniper
- Start date
Alex Wheeler
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They should be at extremes of vertical positioning.
Frequency represents cycles in time. Accuracy nodes are at extremes of the oscillation. More of them in time would shorten the distance between accuracy nodes. So you expect to see accuracy nodes closer together. It makes sense that we are changing frequency when we play with this stuff, however it cant have much effect on grouping IMO
Frequency represents cycles in time. Accuracy nodes are at extremes of the oscillation. More of them in time would shorten the distance between accuracy nodes. So you expect to see accuracy nodes closer together. It makes sense that we are changing frequency when we play with this stuff, however it cant have much effect on grouping IMO
I disagree.
Accuracy nodes are between the physical extremes (highest and lowest angles) of the muzzle direction. Bullets need to leave on that upswing else no compensation for velocity spread happens.
There is virtually no angular muzzle axis change at the extreme. What little there is will put half the faster bullets out at higher angles, half the slower ones at lower angles.
This premise is what Browning claimed their BOSS did.
But it does. I say this respectfully, I'm not sure what you're not seeing. IMO, it's pretty clear in the pic I posted and in tuners making groups both big and small. It seems like you are disagreeing with both, what most everyone else can see firsthand, as well as what can be seen in the pic...and physics. Obviously, I'm missing something in what you're trying to convey. Moving the tuner affects group size...that is clear. If not frequency, what do you think is changing? If it's amplitude, the groups will do the same, but larger or smaller. Amplitude does not affect frequency..two separate things. Serious question..I'm not arguing but trying to see what it is that you're seeing differently.
Alex Wheeler
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Bart, my comments were a generalization. Im fully aware of positive compensation. Close to extremes may have been better wording, but the shorter the range the less this matters.
Alex Wheeler
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I may not be doing a good job of explaining. Forget tuners for a minute. Im strictly talking frequency now. Lets say a cartridge has accuracy nodes 1 grain apart. If we change the frequecy of the vibration I would expect to see nodes .8 apart or maybe 1.2 apart. I dont see that happen. Thats what I mean when I say frequency doesnt effect grouping much.
Exactly. Correct. It's typically on the last part of the muzzle axis upswing a little before it is at the upper extreme.
Positive (thanks to comments by Alex W.) Compensation never happens on muzzle axis downswing.
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Alex Wheeler
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Sure does, its called negative compensation
Ok...I think that gets to what I mean when I say that I can't wrap my head around why working up a load with the tuner on or off still seems to work. The answer is, I don't know. But, what does that logic do to having a wide powder charge node width, where it stays in tune over several tenths of a grain? How can you have a node maybe .8-1.2 grains(or .6 grains wide pert Bart) apart unless the barrel is at a very sweet spot in terms of its vibrational movement, which can be moved by the load or the tuner? We may be talking about the same as Bart may have been alluding to here. IMO, you can't have a wide powder/temp spot unless you are at a sweet vibrational spot. I'm avoiding the term node. It's my belief that either method..tuner or load, can time the barrel to a wide or sweet spot. I hope that's clear..just trying to follow your line of thought.
Alex Wheeler
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Amplitude. If the amplitude is low, out of tune loads are not that bad. I dont really think there are wider nodes, rather they dont go out of tune as dramatically. Spacing is the same, but the bad spots are not as bad if that makes sense. What I see in sporter barrels is high amplitude. They shoot small in tune, and the tunes/nodes are as far apart as normal, but out of tune loads are BAD. If the barrel was heavy, everything is the same but out of tune loads are not as bad.
On bullets leaving on the muzzle axis downswing:
Good enough to frame and hang on a wall..... its called negative compensation
dcali
Bullet Maker
Just to throw a little bit of a wrench into this, it’s not just about where the muzzle is pointing. It also has a lateral velocity that is imparted to the bullet as it leaves the bore. So it’s not just about compensating for velocity variation. If it were, you wouldn’t be able to tune out horizontal groups.
Edit: and for that matter, there should also be an imparted angular velocity (rotation, or tendency to yaw), that would cause an aerodynamic jump at 90 degrees. This may be too small to matter. But then again, maybe not when talking about really small groups. I don’t know how you’d go about quantifying it.
Edit: and for that matter, there should also be an imparted angular velocity (rotation, or tendency to yaw), that would cause an aerodynamic jump at 90 degrees. This may be too small to matter. But then again, maybe not when talking about really small groups. I don’t know how you’d go about quantifying it.
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GSPV
A failure to plan is a plan for failure.
That picture that Mike posted was my 30 Major with Shadetree tuner. “Medium Varmint” Bruno profile Krieger. My standard load of N120. 115 grain 10X bullets. 100 yards. I was moving the tuner one full graduation per shot. I can’t remember if it was in or out.
Alex Wheeler
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I dont believe the muzzle can't point left or right of center.
I don't get into this a lot but I agree. The reason I don't get into it much is because it's counter to what most smart people will say regarding amplitude. I believe that a gun that is completely out of tune will shoot bigger with a tuner than without. Physics will tell us that more weight will reduce amplitude. I can't argue with that but I think it's true, over time. We're not dealing with much time to bullet exit. A tuner shows tune...it tells you when it needs to be moved. It's important to remember that I've NEVER seen a gun go as far out of tune due to condition changes as a tuner can take it. I've said, the biggest condition related change(45°) I've ever seen was worth 2 marks on my tuner and that there is typically 4 marks from completely in tune to completely out of tune with my tuner. I consider it a good thing! We've all had barrels that will shoot just good enough to lose. Was it tune?
Why?
Alex Wheeler
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Why not? We have all had horizontal tunes.
Ok, I misunderstood and I agree. There are some that believe tuners can only take out vertical. To that, I ask "why".
dcali
Bullet Maker
Is it just me or are horizontal mistunes often worse than vertical? Anecdotally, it seems like every time i shoot a really badly out of tune group, it’s horizontally strung. Anyone else experience this or do I just have selective memory?
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