When fired from a longer—4- to 5-inch barrel—Remington's 115 grain JHP load performed very well expanding more than any other load tested. However, from the shorter-barreled compact 9 mm, the 200 fps velocity loss drastically impacted expansion and in turn the bullet penetrated almost 2 feet in the gelatin.
Hornady's Critical Defense ammunition has a good reputation of being able to expand even after penetrating intermediate barriers like thick clothing. This is important but so is wide expansion. When fired from the short barrel of the Diamondback DB9, the Hornady load only expanded to 1.4 times its original diameter.
Wilson Combat's 115-grain XTP load for the 9 mm is rated at 1,250 fps from a 5-inch barrel. Velocity from the 3-inch barrel was about 100 fps slower and expansion was short of the desired 1.5 times minimum.