Here's a quote from the 2018 props policy. You'll have to check the 2019 policy once it's up.
Gun-like Props: In accordance with Baltimore law, all props that can reasonably be perceived to be a real firearm due to their color, size, shape, or other characteristics are prohibited from the convention. Gun-like props that do not fall under this restriction must have an orange tip as part of the prop at the point of manufacture. (That is, using orange tape or paint on the tip does not qualify unless you made the prop yourself, e.g. out of Styrofoam.) Furthermore, no airsoft guns of any kind are allowed in convention space, disabled or otherwise, and no ammunition of any kind may be carried. Toy guns (such as NERF guns) must be unloaded and their magazines, if present, must be removed except during photos. In all cases, take care to avoid gun-like props with color schemes commonly found on real firearms such as black, gunmetal gray, or tan.
Guns: Real firearms, even if disabled or unloaded, are strictly prohibited in all convention spaces. If you are an off-duty law enforcement officer carrying your sidearm through convention space, please come see the Head of Security when you enter the con so there are no unfortunate misunderstandings.
I'm not staff, but I think your prop has a few strikes against it: It's black, no orange tip, and somewhat realistic in appearance. I'd definitely check back closer to the con.