Dooms_day wrote:pick from back to front 4 times and it pops open!
Not necessarily. There are spool pins in this lock, and if one of those catch, you may need to start over.
Also, for the OP, if you are seriously interested in picking locks, then you need to get/make some serious tools.
Paper clips will not give you a good feel for what is happening inside of the lock.
I suggest looking in the Manual Lock Picks forum, and making your own picks after doing some reading.
There is a great video on youtube by Pyro on how to make picks out of hacksaw blades.
All the best