Ford, General Motors and the rest never wanted anyone to work on their own cars either and that never stopped anyone until they put those darn computers in each and every model. It won't be long before you need to take your car in for air in the tires. I bought a new Toyota, and I can't go just anywhere for tires because of the computerized valve stems. Thankfully, I can still change my own oil because Toyota now gives the procedure for clearing the code for the oil change. WHEW ! ! !
So I suppose if the gun makers wanted to stop someone from working on thier own equipment, they could computerize each and every model.
Until then, holding torque specs for action screws as proprietary knowledge is somewhat stupid, because it isn't going to stop anyone from doing their own work. With the knowledge, owners could be doing it correctly, now couldn't they...
Somehow, manufacturers think that holding certain information 'close to the vest' is the best policy. Maybe they don't want anyone to know that they don't set the screws to any certain spec under mass production practices. It would cost too much. I am positive that all they care about is that the screws are there and tight, and not missing.