[1tonne]

Good write up James. It is always useful having another perspective.

One thing. I prefer to use 0.36gm bb's at 500fps. In saying this, some other techs like to use 0.4gm bb's at that fps rating. So experiment.
If you get the 430mm barrel then you will be able to shoot both weights well.

 

[1tonne]

Anything over a M150 and I would get a 90 degree trigger. Makes for an easier bolt pull/push and your cylinder will not wear. It also creates reliability on the field for you.

 

[1tonne]

Wrap solder around the piston and hold it on with electrical tape.

 

[1tonne]

Make sure you have Teflon tape around the thread on the air nozzle as the air may be escaping through there.