Quote Originally Posted by snippy View Post
I haven't taken it apart as yet so wil need to look at the piston rings , they seem very dear to buy I may spin something up un my lathe to replace them as the last time I fired it it hardly broke the cardboard box
firstly try the breech seal ...a bit of tissue moistened with oil or whatever placed over breech while you fire a pellet. If leaky it will blow off.

If breech is fine, consider trying O rings in place of the original rings if you do not want to buy originals. I replaced the rings on an Osprey with O rings and it was fine ... my notes say BS116. I believe they are the same for the Hawk.
Cheers, Phil