Dear Abhay,
Let us first get the term 'closing a position' clarified to its glory. The recruiter and his worthy work comes into play only when the hiring authorities/admin/ senior management takes a hold on the quantification and quality of manpower that is needed in the firm and by what time. The recruiter, again, has a lot of work responsibilities varying neatly on the arena, industry and the country of the functioning of firm. In India, all that the recruiter does is formulation the JD and JD, posting and floating the job advertisement, creating a talent tool, shortlisting, confirmation and raising invoices.
Look! I might be making it simple a task, but it takes a lot to close the position in a given time-frame. All I would like to say is that when someone is hired as a recruiter, he is tested only on the barometer of how comfortably will he work in time-bound pressure. Yes, if you are solely into internal recruitment, the time frame might already be shortened owing to the lapse at the various pedals of organizational hierarchy. As discussed by another mate, the management, at times, take their own sweet time deciding on the mandates of the vacancy which would leave the recruiters with lesser time to close it. But you will also have to take into consideration that the recruitment industry of ours is a very mediocre one. Any trivial employee with a tool of job portal can deliver almost the same result that you do. The only thing that makes you stand out of that mediocre chunk is the level of comfort you seek in delivering even in short notice.
Wishing you all the luck!