I had one back in the late '80's.  In all honesty, I was pretty disappointed with it.   As I recall, it used a piece of hose for a recoil buffer.  The rear grip was also uncomfortable as heck too.  
The positives of the gun where :  it was pretty accurate for what it was, and it looked cool as heck.  I sold mine in the early '90's for a loss and do not regret it.
hth
ka