Nodes. How far apart are they usually?

[slowbalt]

In your experience, how far apart are nodes on 6BR? Thanks!

 

[NC/Br Shooter]

.005

 

[gunsandgunsmithing]

This is not something written in stone but it's absolutely important information to know. My tuner test shows this and quantifies it as well as smaller incremental changes, also imperitive info. It's maybe the most important thing the test shows the user. I think this test is like a tuner bible but it can also be used without a tuner. No matter your tuning method, ya gotta establish and know the value of each change. I think we can all agree with that statement because without it, we're simply guessing.

I'll need to edit to add my test target and I will but if you do it ANY OTHER WAY, down to the finest detail, it's simply NOT my test, which your guess is as good as mine to interpreting it in that case. Lol! Make your own target exactly like it and don't skip or shortcut anything. You'll still need to establish increment values with whatever tuner or tuning method you are using but this will help with that. If my tuner, we've probably already covered it but you can call me about the details. Establishing increment values is step ONE. Without knowing that much, you're just guessing. Nothing more and nothing less. I mean, say I see some straight vertical in my groups...Do I change the load a tenth or do I change it a pound? Seriously, sorta.

 

[TrapperBR549]

This is not something written in stone but it's absolutely important information to know. My tuner test shows this and quantifies it as well as smaller incremental changes, also imperitive info. It's maybe the most important thing the test shows the user. I think this test is like a tuner bible but it can also be used without a tuner. No matter your tuning method, ya gotta establish and know the value of each change. I think we can all agree with that statement because without it, we're simply guessing.

I'll need to edit to add my test target and I will but if you do it ANY OTHER WAY, down to the finest detail, it's simply NOT my test, which your guess is as good as mine to interpreting it in that case. Lol! Make your own target exactly like it and don't skip or shortcut anything. You'll still need to establish increment values with whatever tuner or tuning method you are using but this will help with that. If my tuner, we've probably already covered it but you can call me about the details. Establishing increment values is step ONE. Without knowing that much, you're just guessing. Nothing more and nothing less. I mean, say I see some straight vertical in my groups...Do I change the load a tenth or do I change it a pound? Seriously, sorta.

If a person isn't using a tuner I assume you would shoot 15 3 shot groups increasing the charge weight by a certain % with each group?

 

[gunsandgunsmithing]

If a person isn't using a tuner I assume you would shoot 15 3 shot groups increasing the charge weight by a certain % with each group?

Yeah, lots of variables when you start talking all different cartridges, different powder characteristics and such but by any method, I believe step one is quantifying whatever change increments you use has to the tune. I use group shapes more than anything and I look for where I see groups go from dotting up to straight vertical, as that's very typically the first group shape as it progresses away from a sweet spot. Say with a 6 ppc, ime, that's about .3gr of n133, commonly. But ya just have to establish that much and then go thru the complete progression from extreme in tune to all the way out. I use 15 groups because I already have done the legwork with my tuners to know those approx values, 1 mark at a time and that with that known value, that 15 marks is enough to go through a complete nodal cycle. That being, in tune, completely out and back in again. The two sweet spots will typically have different poi, one high and one low.

 

[TrapperBR549]

Are you looking at group size or poi? What role, if any, does a chronograph play?

 

[slowbalt]

Are you asking about powder nodes ?

Yes

 

[gunsandgunsmithing]

Are you looking at group size or poi? What role, if any, does a chronograph play?

I look at both. Actually, not even size as much as shape. It's in tune when it shoots smallest at top or at bottom and the next groups confirm it by their shape. Ideally, I want bullet exit to be at the top of bbl swing. Pretty much just like a ladder that shows poi of sweet spots. At this point, a chrony plays no part in it.

 

[gunsandgunsmithing]

In your experience, how far apart are nodes on 6BR? Thanks!

So many combinations, ya just have to test it but about 1.5-2.0 grains between sweet spots is a close guesstimate with a BR. One is in tune at top of bbl swing and the next sweet spot will be at bottom. Just no replacement for testing it with your own setup and combination of components though.

With a BR, I'd suggest starting by shooting in .3 intervals and just keep going until you see two clear sweet spots and compare their poi to one another. It'll be several tenths apart. Like I said, likely at least 1.5 grains, IME. It's a big swing. Equal to about 8-10 marks on MY tuner. More than that on some others.