Ok, i just built a new AR- FN upper w/ wilson chromed lined M4 bbl on a RRA lower...everthing is BRAND NEW! Yesterday  took it to the range and was very disapointed to find the bc "hanging up" on my used ar carrier...i read through all the threads here, put a brand new Colt M16 b,bc in there and went this afternoon to make sure everything was kosher..well, the bc didn't hang up, but my triger doesn't reset now! Everthing is brand new! I don't understand. It appears to pasa all functionality tests, it cycles the round, but the trigger stays back. When i manually pull the chaging handle back and let it slam home it shoots, ejects, chambers..everthing, but no BANG!  Upon observation of the rounds thatweren't fire(manually ejected by myself) i noticed a small dent in the primer, but not enough to set it off..i don't know if this is normal...HS problem?  Please help...this pains me as i spent the money i was supposed to fix my car with on a new "No Ban" AR!


                                                         Speed

well...i think i got it figured out...disconnector stuck

With the pins and the FCG parts lubed,

The trigger spring legs go forward, the loop under the front and the legs sitting on the bottom of the receiver cavity.

The hammer spring hook goes on the back side of the hammer, with the legs resting on top of the trigger pin.

The disconnector spring large side of the coil goes into the trigge slot, and the small coil side goes up.

On the disconnector hook and mating hammer hook, knock off any burs with a stone.

Also make sure that you have installed the pistol grip screws washer, and the tip of the screw in not up into the bottom of the receiver cavity preventing the trigger from fully resetting (If you can set the selector on safe, then it's fine).

Thanks dano...i got it under control now...i had a bur stuck in between the disconnector and the trigger; the pin caught it when i put  it together and prevented the disc. from pivoting...tightest fittin' damn lower parts i EVER got! It's my own fault for racing through thte initial build...thanks again!