Depends what you mean by 'pit', and what the audience are like.
My favourite position for recording is 5-10m back from the stage, however if this is the 'mosh pit', you dont want to be recording in it..believe me I've tried. Move further back, if you can.
By the way excessive heat and jolts may shut down the JB3 (at least my main machine does, I'm testing model #2 later today). It doesn't skip. Dont let this put you off; its a fine recording device, and dirt cheap.