just make a dummy projectile that has an hp then move it periodically with an angle offset, then add an if condition if dummy is dead then stop the periodic.
That is essentially what a missile system is, execpt its alot more efficient and configurable, and without the specifics of targeting as in your case.
Finally finding about some of the bots that are flooding the users online - bytespider apparently is a huge offender here - ignores robots.txt and comes in from a ton of different IPs
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.