Homemade Mini Coaxial Airgun

Step 4 Finding the right size chamber and cutting it.

Well since your barrel is probably a different length then mine you are going to need to find a good chamber length for your barrel length.
Compare the length of your barrel to your chamber and then about 1in farther down make a mark with a pencil or pen. This is where you will cut with a hacksaw.
Next you cut at the mark you made trying to keep it as sqaure as possible. If you want you could you a mitre box but I dont assume that to be nessesary.
After you have made the cut smoothen it with course sandpaper.
And you have your chamber.