wrong - the frames are identical. maybe you saw different backstraps on the pistols. most of the SW99's are in 40 cal but I have seen a few in 9mm. either pistol in 40 is the snappiest 40 I've ever shot due to it's light weight and hi bore axis. my P99AS was very accurate and had a sweet trigger.I have a Walther P99AS and it is a wonderful firearm. Never had any failures of any kind with it even with low grade ammo. The SW99 is clone, albeit a bad one, of the Walther. The grip angle of the SW99 is different from the P99 and as mentioned the Walther has a tapered slide.