Wanted to pick someone’s brain about how on earth this worked. (Military radio here)I  was recently in the field and built a field expedient HF antenna. Used what was probably 22 gauge speaker wire if I remember right, may have been heavier than that though. We took about 30 feet and wound it tightly around a conductive antenna mast section with insulation on the outside, essentially a fiberglass tube with copper inside of it. We didnt place a reflector at the base. This was attached to an amplifier pumping out 60 watts and mounted to a vehicle.

I know a helical wound antenna is directional, casting its RF most heavily in a direction parallel to the mast and perpendicular to the reflector at the base. Somehow though, this one effectively acted as omnidirectional, we hit another station a good 3 miles across somewhat flat terrain in a long valley, granted VHF/UHF comm was degraded by this same terrain.

Trying to figure out why this worked, i have a few theories but they may be total bunk;
1. Reflector location, having the reflector in the middle meant the field was altered and cast a typical donut-shaped RF field off the mast.
2. Having the wire wound so tightly caused it to act as if it were one solid section of antenna
3. This was actually acting as a normal helical wound antenna and we were unintentionally shooting NVIS but still hitting our nearby stations.  

Ive been stuck on this for 2 weeks now, input would be awesome. Thanks in advance.

Possibly ground wave propagation? Someone smarter than me will be along...

You seem to be be hung up on this, so let me push you down the rabbit hole - download EZNEC (there are others) and model your antenna. I hear its not too hard to learn to use, and you can probably really drive yourself nuts with it!

Sounds like a modified helical antenna.

Mostly used for commercial operations.

https://www.m2inc.com/categories/commercial/antennas/helical.html

Even at 3 miles on VHF they will be omni-directional. 30 miles, not so much.

Do not confuse normal mode helical antennas with axial mode helicals. What the OP is describing is a normal mode helical, because at HF freq's it's pretty difficult to build a helical with a diameter that is any significant fraction of a wavelength.

Paraphrasing Wikipedia...

In the normal mode or broadside helical antenna, the diameter and the pitch of the antenna is small compared with the wavelength. The antenna acts similarly to an electrically short dipole or monopole. The resulting RF is linearly polarized.

The problem with any electrically short antenna is that it will be horribly inefficient. The size vs. gain trade-off is quite severe. You are often much better off with a short random wire and a tuner. I once built a 40M slinky antenna and it was essentially a dummy load. Wonderful VSWR, but absolutely awful gain.

The most common use for normal mode helical antennas is in our favorite "rubber ducky" VHF handheld antennas. You rarely see such things for HF applications, but obviously they do exist.

Just for completeness and clarity, there is also the axial mode helical antenna. These are the antennas that everyone thinks of when satellite communications come to mind. These are almost always VHF/UHF/SHF antennas, and the diameter and pitch of the helix are comparable to a wavelength. The antenna functions as a directional antenna radiating a beam off the ends of the helix, along the antenna's axis. It radiates circularly polarized radio waves. This is not what the OP was describing.