I just recently purchased a Bushmaster M4 Carbine with 14.5" Barrel. After shooting it for the first time with wolf ammo no less, I wanted to scrub it down and remove all the grime. After giving it a good cleaning I reassembled it and oiled the bolt and charged the gun. The bolt went all the way to the stock, but wouldnt move, nor would it dislodge from the buttstock. I looked down and to my disbelief, I saw the recoil spring on the ground. I had forgotten to re-install it before assembling my rifle! I thought I had permenantly damaged my new toy. After trying to dislodge the bolt from the stock and removing the take down pins the bolt still was jammed. I finally pointed the muzzle directly and the carpet and gave it a good whack and it came loose. I must have drank 5 beers and sweat about 5 pounds in the belief I had ruined my rife. Everything is fine now, no problems. I just thought this was a funny story to share in case anyone else encountered this problem.

I can say I did that so dont feel bad. Something felt like it was binding so I took the spring out. Stupid, Stupid.... STUPID! Anyways I removed the stock to undo it and all is good now, live and learn.

NEVER remove take kown pins with the bolt locked to the rear...   pins and springs will leaarn to fly.
personal experience