It sems to me that it's the army getting its cheeks parted. At present on Ebay there are Bayonets, bayonet frogs, Mags, drill rounds, blank brass, drill rifle grenedes, spent smoke, rifle hand guards(!), cocking handles and even fig 11 targets!
I can see how a cocking handle could go missing (although not easily), but how the hell can you explain the loss of your hand guard!!
I have seen in the past gas parts, surly these are illigal to sell and own.
Why dont the armt take action? all the above are property of the MOD, and last I checked it wasnt encourouged to bring your brass and spent smoke home.
While it is a part, I believe that the cocking handle is not considered as a 'component part' under the act.
It tends to get a little silly when they're undefined, a block of metal being capable of being turned into a firearm, etc.