hey guys, this is my first build here.  I was wondering...... I finished putting together my stripped lower receiver (superior arms), with a bushmaster lpk.  I had the disconnector spring "left over".  Is this normal?  Where is it supposed to go?  

thanks for your help.

Read the tacked BIY thread and pay special attention to the LPK.

Your disconnector spring should sit between the disconnector and the trigger.  There is a detent built in to the disconnector which retains the spring.

Do NOT fire the gun until you're sure you have the disconnector set up properly!

thanks for the info.  After a closer look at how the parts work together, I realized that the disconnector holds the trigger back when pulled. Then until the trigger is released the disconnect "lets go" of the trigger and leaves it cocked, ready for the next pull.  
As always, I can always count on you guys for excellent information.  

My RB Precision "1st time builder kit" had that spring already installed with some kind of green loctite stuff all over it to hold it in until I got the FCG installed.  I just took that trigger/hammer/disconnector/selector and pins out and put in a DPMS set (it was a DPMS lower and I want the non-DPMS notched trigger from the RB Precision set for my DoubleStar lower build).  When I put in the new DPMS parts, I had to try to figure out where that spring went too - never dealt with it before.  It just pops down in the top of the trigger into a hole for the spring base to snap into, and the disconnector holds it in.