Hello , i was testing with anti-ballistic missile and i found missiles dont chunkloads (with an custom missile)
Im in the last version , the 1.0.27 (4880) , got screenshot

And other glitch is when an air raid siren is running , you unload that chunk and load that chunk , the siren still sounds enabled or disabled.

What's your modlist? Optifine is known for breaking chunkloading in most things, including missiles.

Sorry , i didnt saw your message , i have OptiFine installed but anyways there the modlist