How can I force Terminal.app to take up exactly half of my screen?

I'm using Spectacle for Window Management and I regularly use the commands to split my screen horizontally for exactly two windows. It works quite well for most things, but not for applications like Terminal.app or Emacs, which size themselves down just a little bit so that the window size goes together with their monospaced text view. I see Spectacle resizing them to exactly half of the screen, and then the windows resizing just a tad right after.

Emacs on the left, Terminal.app on the right:

Is there any way to force these windows to stay the size that Spectacle is trying to set?

This seems like a non-issue, but it quickly becomes one when I have a more colorful desktop background. It's then quite distracting to have e.g. bright orange pixels all around those windows.