I have both Gold Dots and HST in stock in 9mm 124g standard pressure flavor for all of my 9mm defense duty guns
What I noticed is that there's a visually noticeable difference in the overall length of the cartridges, where the Gold Dot ammo is longer than the HST (and these are same weight, same caliber rounds, and the HST has a larger cavity to boot, probably just seated deeper)
With the issues a few people have had with feeding in their Kahrs, would a shorter cartridge be preferable by being less prone to catching the feed ramp or hitting the slide release?