SpudFiles

*i Realise this is a double post, but if i just edit the last one no one will notice my new question*
well seeming as the title of this says sizes, i just thought of a last minute size question. airsoft bb's are 6mm, but how precise is that? will steel tubing with an internal diameter of 6mm work as a barrel?

Yes, that will work well.
Airsoft BBs are actually 5.93 mm, try to find 9/32" brakeline, it has an ID of 6.03 mm.

Already ordering from mcmaster, and its like 8$ for 3m of the stuff. il just stick with it. Thanks for the info