Homemade Mini Coaxial Airgun

Step 5 Piston

The piston is rather simple to make.
Just take your copper cap and epoxy some inner tube cut to size onto the top. Use the same epoxying technique as when you epoxied on the barrel.
Then wrap the cap in your choice of tape until it fits well but slides easy in the 3/4in pipe.
Thats it, you piston is done.

Of course you don't need to use a copper cap for the piston. There are much better piston materials out there, such as a casted epoxy piston.
Its just the copper cap is very easy and reliable(I've shot it more 300 times without a single problem).

And sorry I have no pics.