No worries JiggleToes, I’ll keep at it and try to keep this updated if I find a solution. Thanks for the extra info too, i need to work out how to catch a touch event. 
Thanks Hitpaws,
that’s actually what I have currently but the main issue I find with it is the projectile is so fast that you only hear a minuscule part of the sample. You don’t get the benefit of the full flyby recording. An arrow flyby sound for example https://vimeo.com/musicstore/track/205434/arrow-fly-by-06-by-audiosocket
You only hear a very short pft, if that much. So I think it’s best to trigger the full sound somehow
I think I’d like to give Jiggly’s idea a try, would you perhaps know what nodes I’d need to use?