freediver

I'm just finishing up working on my BBB, thanks for all the help with the pictures here. Nothing new here, I eliminated the orange tip completely and used a piece of 1" slipxslip pvc and a 1"x 1/2" reducer to a 1/2" pipe.

We shoot indoors in a small area and my buddies already banned the use of my longshot and of course the doomsayer so usually I use my longstrike. I'll try to look for the pictures where I tore them apart, the longshot has a lot of beefed up internals that are somewhat unique.

My main question is that I'm looking for a mod to enable the bbb to shoot a clipped version of unmodified sonic darts (we are looking to level the playing field and have everyone use the same darts). The big problem I'm encountering is that 1/2" pvc is a bit big and too much air is lost. 1/2" copper is too small, and PETG is way to small. So I have two questions:

1. Is there a material that you have used that fits sonic darts? I'm thinking of spray painting the inside of the 1/2" pvc to raise it a mm or so and get a tighter fit.
2. Is there any material that fits tightly over 1/2" pvc so I can make a breach using standard pvc?

Thank you for your help.