There is incontrovertible proof that those who talk about barrel harmonics do not know what they’re talking about, and that proof is in the very term they use to talk about it.

First; the term “harmonic” is a very specific term for an integral multiple of a fundamental vibration frequency. Since a barrel is (usually) a somewhat irregular object tethered at one end, I question whether most of them have a harmonic overtone series at all (like a guitar string or the air column inside a flute) or a primarily inharmonic one, like a bell or a cymbal. “You keep using that word…”

Second; the fundamental frequency of the “resonating” barrel is being ignored (by the language at least) yet the fundamental is often, or probably, more significant, i.e. it probably has a higher amplitude than the higher frequency vibrations. That’s usually very much the case with a vibrating body unless it’s being dampened at the fundamental. So why, particularly, are we discussing overtones (harmonic ones or inharmonic ones) and not the fundamental?

Third; don’t even talk to me about barrel harmonics, or barrel fundamental vibration, or inharmonic barrel overtones (A.K.A. “partials”) on an AK or a 30 Carbine, et al barrel. Just don’t.

I once had to do this with a class of music majors during a seminar I did at the U of Idaho. We were talking about advanced tweaks, the last one percent, of what goes into the design and structure of a musical instrument to make it a really fine one, and the students were responding as though I were talking about major issues. My fault. I should have been more clear at the outset.

So here it is; you don’t address the last one percent on your AK. It’s not a beanfield rifle. Please. There are several other factors that totally overwhelm the last one percent (like the previous 99 for example) and so if you address the last one percent as though it were “the issue” you’re ignoring the issues that matter.

I fixed a minor bug in Field Ballistics. The new version is 1.1.1.0. It is available on the Windows Phone store now.

The bug was that under certain situations you could delete the last target. Other places in the app required that at least one target exist at all times. After deleting the last target the app would immediately crash.

As a side note: I submitted the changed version Sunday evening. It made it through Microsoft certification in less than three days.

I released a new version of Field Ballistics for Windows Phone earlier this week and it made it through Microsoft’s test gauntlet this morning.

Here are the changes in version 1.1:

A crash that occurred when measuring inclines has been fixed.

Auto conditions retrieves air pressure from the weather service and allows manual input of air pressure independent from altitude for user defined conditions.

Target range can now be set in the range edit box in addition to moving the target push pin on the map.

I found what appears to be a minor bug in some Windows Phone 8 devices.

It showed up in my Field Ballistics program. I have code that looks like this:

// Can we focus only on the target?
if (this.cam.IsFocusAtPointSupported)
{
    this.cam.FocusAtPoint(0.5, 0.5);
}
else
{
    this.cam.Focus();
}

On someone’s phone this raised a “System.InvalidOperationException” on the call to “FocusAtPoint”.

What appears to have happened is that the phone reports IsFocusAtPointSupported as “true” but doesn’t actually support it. It’s not all that big of deal but it does mean I’ll be releasing an update a little sooner than I had planned.