Harmonics Question

[croberts]

I have been sitting around pondering something that you all will most likey know the awnser to:

When looking at a barrels harmonic frequency and group size I understand that it groups in steps. By that I mean that the barrel will group well at one velocity and then it will have another tight shooting group at a higher velocity with the same bullet. Exmaple: 100gr bullet 2800 fps and 3000fps.

But what I wonder is does this harmonic vibration act simarily with another bullet weight. What I mean is if you push a 85 gr bullet at say 3100fps with great groups could you possiably get the same tight groups at the same velocity if you could push say a 100 gr bullet at that speed??

 

[Winchester69]

It's more art than science. You have to look for the "sweet spot" for each loading independently of other experience.

The harmonics thing is, I believe, a theory. Until someone is able to establish the relationship that you are asking about, it will remain a theory. Considering the number of variables that have to be controlled, it is unlikely that this will happen anytime soon.

 

[croberts]

Yes, I know it is a stretch. I have never been able to duplicate results in that manner, but I was just wondering if anyone else ever thought it may be possiable.

 

[croberts]

That is pretty interesting that the ladder test does not repeat the same data on an identical test. I have never tried the one shot at .2 gr increments testing theory. I always felt I would not know if I pulled off or not and spend lots of time looking for a sweet spot where it may not exist. I don't know just OCD about it I guess.

 

[CPorter]

The closest thing to describing what occurs that I have found is the shock wave theory. You can find a article on it here:
http://www.shootingsoftware.com/barrel.htm

I've used this theory in conjunction with Quickload to develop loads and found it to get me quite close to the actual node.