I have three AR's.  The first is a factory olympic.  It has always been a good rifle and I am very happy with it.  I noticed that the trigger is about on par with the M-16's I was issued in the Army.  Not real heavy ot light, with a little bit of creep.  

Recently I bought lowers from Rock River and a Stag arms.  Both were lowers only, with the Rock River internals being already assembeled at the factory.  I have found this one to have a trigger pull that is noticeably heavier than my Olympic, but also alot more crisp - almost no creep at all.  The Stag lower I put together myself with an Olympic lower parts kit.  Everything went together alot easier than I had expected (my first build).  However, the trigger is both alot more creppy than my Olympic and noticeably lighter.  

Why is this?  What causes an AR trigger to be heavier or lighter/ creepy or crisp?  Is it something I did wrong/right?  Were the parts of one or the other simply inferior?  

I'm very curious about this, please forgive my ignorance.

-K

Someone's gotta know!  

-K

Well you hit most of the major points on what cause the variance in the trigger pulls. The tolerances in the parts, springs and even the lower rec'r can cause these problems.
In fact if you notice , this is why some of the major trigger producers have made self contain trigger units in a housing. This is to keep the alignment/geometry of the parts perfect, no matter what lower you use!

Stuart

variance in manufacturing
like how two like barrels are capable of shooting differently.

two identical motors but one producing more power than the other.