Since the buff, the stubber feels a little more compelling, but not by much - Heresy/Damnation as a frame of reference. Its lack of performance relative to Ogryn’s other ranged options isn’t so much to do with the damage each round does (though damage falloff at range seems extreme), but actually getting them on target. Your chances of hitting an individual, human-size target diminish rapidly outside maybe 10m - even more so if you’ve already been firing for a second or two, doubly if you’re anything but crouched and stationary. Even then, targets at what you’d expect to be point-blank range can manage to survive a good few seconds under direct fire through sheer luck - especially if they’re already running for cover and especially if you’re at an odd angle. It makes the gun feel really unrewarding and dissatisfying.
My suggestion is to tighten up its accuracy/stability stats a fair bit, so bullets actually go where it’s pointing. To counterbalance, make “where it’s pointing” a little harder to control while firing; give it a somewhat more violent and less predictable recoil pattern that the player can compensate for - not quite un-braced rippergun levels, but closer to that. Maybe its damage would then stand to be dropped back down a little.