We had them mounted on the the AVGP Cougar. Men I hated those! During my apprentice course, I was day dreaming during a pull back test and got smack right in the head by the ordnance!
(you insert a tool in the barrel and with a chain and hoist simulate a recoil, then let go suddenly, and you want to examine the ordnance coming back forward under nitrogene pressure)
Lucky for me, they where out of the system when I did my latest course