I still have mine, bought it new in '82, took a fair few bunnies with it in the day, basically wore it out
not sure how true it is, but at the time it was in the shooting rags that the project came about because the Stirling Company had lost a contract to make AR15's and they were .22 because they already had the barrel blanks in inventory, they are certainly heavy duty enough!
You Cannot Reason People Out of Something They Were Not Reasoned Into
"Politicians like to panic, they need activity. It is their substitute for achievement" Sir Humphry Appleby