A barrel for a modded nightfinder airsoft gun?

i have a 8 year old bro who has a bunch of nerf guns. He wanted play airsoft with me but doesn't want to get shot with my 400+ fps airsoft gun. I've been searching some things on instructables and found a way to change a nerf gun into a weak airsoft gun. My brother let me use his nightfinder and i ripped out the air restrictor. so now im supposed to make a barrel. He doesn't really like the idea of cutting up one of his darts so what is another item that i could use to make a barrel. he doesn't mind a decent fps on the gun just nothing too extreme. any other suggestions for other mods are accepted as well.

Nerfgenius8 years ago
I suppose you could wrap a pen, straw, etc. in tape so much that it fits nicely in the barrel of the nightfinder