I've run more than a few 165gr JHP Underwood 10mm rnds through both my stock '20 barrel and my 6" Glock Hunter. All functioned flawlessly and only
some of the fired casings have any discernable hint of a "Glock smile". On those casings; the "smiles" are
barely visible, not easily photographed, and have little to no effect on reloadablility... i.e. the 165gr JHP Underwood rnds are loaded to the original full-power, (or full house), 10mm specs, as all Underwood 10mm rnds are.
They're
currently my favorite rnd to shoot, (I won't get my 135gr nosler JHP Underwood rnds till Friday
), very versatile and extremely damaging to
anything they're fired at... although the best rnd, (of the various factory 10mm I've fired), for turning cover into concealment is Underwood's 180gr FMJ, (>1300 fps)! :50cal: