HB semi auto is definitely a lot of fun. Not really viable (or comparable to marksman rifles) at long range, but it certainly makes the Badger better at long range than it normally is. It has a 4m longer 2 hit kill range than the suppressed MR-28, much less recoil even before you consider that every semi round fired from the HB has 30% less recoil, a higher centrespeed and the same rate of fire at 600rpm.
The only real con is that it drops off to 4hk - unlike the stronger MR-28 - at around 35m. But it can 2hk out to 28m if you hit centre mass twice, and 23m when you only hit centre mass once.
2 shots at 600rpm is the same as 3 shots at 900rpm, so if you can train your trigger finger (this is for you Run N Gunning), you'll be killing as quickly as you would with a Bizon or CBJ in their ideal ranges, only it'll be out to mid range
I personally find getting close to a 600rpm fire cap tough with a PS4 controller though; the triggers are strange. On MW3 with my 360 controller I could easily hit 900rpm (1200 was the cap) with the P99 pistol, or even the Barrett...not that I played with a sniper like that, I promise haha! On Ghosts though, I seem to be firing 600rpm weapons about as fast as I do with the IA-2 or SA-805 semi (514rpm), only with slightly less 'jamming'. See if switching to the 'Flipped' controller layout helps you, if you don't use that already, so that you're firing with the more responsive R1 button.
FAD semi is worth a look too. Small 2hk range (tiny with a suppressor) and you HAVE to hit torso or head twice to get that 2hk, but it's a 3hk forever after that...600rpm with nice recoil and irons too, plus a crazy big mag. I've used it on Stonehaven with great results