Not bad at all!

You should really consider a three-way valve as a pilot, much more efficient in terms of air use and more powerful due to quicker piloting.

Will have to look in to that, for now though I just use a ball valve to prime it then close the valve and fire with the blower. Also had to ...

This is my first really successful build. Tried a couple others that didn't work. So here we go this is a breach loading blow through bolt design I came up with while walking around the hardware store.
Here's the parts list:
1- 1/2 x 6 inch brass nipple
8- 5/8 x 1/2 x 1/2 inch nylon spacers
1- 1/8 ...