First I'm not a gunsmith. I picked up a 1976 94 on the weekend. Nice shape, shot wel etc.
I tightened the screws on the side plate without first loking to see what they hold.
The head broke from the one that adjusts tension on the loading door, leaving the rest of thescrew inside.

Anyhow, I have it dropped at a smith. Should this be a big deal to correct ?

Is the loading gate still attached or did it fall inside.The screw dosen't adjust tension on the spring, it only attaches it. A smith should be able to punch the headless screw out,if part of the head remains preventing him from punching it out, or sometimes I've seen the receiver threaded along with the spring nut, he may have to drill it, the door will fall inside, he can remove it through the port and take the remains of the screw out. If he drills through the threads that the screw goes into on the spring that is attached (actually part of the loading door) he may have to replace it. It can try the patience getting it back in.

In most cases its the leaf type spring that breaks at the panhandle of the door near where the screw attaches and the door needs to be replaced. The way you describe it, it sounds like a broken screw only. Either way it shouldn't take more than a few minutes for a good smith to put it right if you don't feel you should try it yourself.

Thans. THe door is still attached, but loose and swings out