No it's not, because the hammer on the Rhino is false, while it appears to be functional (in relation to firing the the weapon) in Destiny. The hammer on the Rhino is simply there to indicate that the firearm is cocked... manually or otherwise. Meanwhile, the hammer on the hand cannons in Destiny appear to be functional (given the fact that all of them except The Last Word appear to be double-action). If the hammer is functional, then the hammer can't be aligned with the top of the cylinder while the barrel is aligned with the bottom.