I don't know that I could be a company, as my uses and thoughts are generally weird compared to what all the books show and what folks, want, vs actually need.
Of course I always tend to build to my uses, and granted my uses are not those of others.
18 inch barrel would be the least though.... and frankly you don't gain that much with tubes over 20 or maybe 22.
IF I had to have something shorter it would be a SBR instead of just going 16
