I bet that puppy has some bark. That said, I'd like to see some numbers on the actual muzzle velocity. It's going to take a stout muffler to handle the amount of still burning powder ejected from that short barrel. A suppressor capable of handling the 350 Legend from an 8.5" barrel is going to be long, heavy, and expensive.
As a side note, shooting suppressed inside a closed area doesn't help as much as one might think. Unless using low power ammo(22lr up to 9mm subsonic) you're still going to get ringing ears. Even shooting suppressed outside with walls or vegetation to reflect the sound can be louder than is comfortable or ear safe.
I "demo'd" a suppressed 5.56 AR for a group of interested people last year. Conditions were perfect: the humidity was fairly low, we were shooting across a low swale into a sloping hillside 150 yards out, and there was a 5MPH tailwind. The report (actually the lack of)was impressive and all were quite surprised. Two guys had put their ear muffs on even though I said it was unnecessary but took them off after the first shot. Now, had conditions been different: the backstop closer and more abrupt, higher humidity, some sort of building or treeline along side the shooting position, the results would not have been quite as impressive.
Suppressors are a terrific tool but NOT MAGIC. Expecting a short barrel firing a fairly high capacity cartridge to be ear safe within a close space isn't going to work.