I have a colt 1991 series 80 which I just got back from wilson. I had sights, trigger,hammer+sear,and beavertail done. Well I just cleaned the pistol and was going thru the function check as instructed in the colt manual. Everything checked out except one. When I pulled the hammer back slightly I hear the sear slip onto the safety shelf .. ok. Now the manual says to lower the hammer to engage the safety shelf - I do that (the hammer is now sitting on the shelf slightly away from home) Now the manual says squeeze the trigger again and the hammer should fall off safety shelf - well this isn't happening - when squeezing trigger my hammer wont fall home from shelf. Is there something wrong with my pistol? It used to do this before I send it to wilson. I haven't tried firing the pistol yet. Oh one more thing - if I squeeze trigger while I assist by pulling back slightly on hammer - then the shelf dropps but without relieving the pressure it wont drop no matter how hard I squeeze - well, i have not squeezed with all my strength as I know it should'nt take that much.

Can't help because my series 80 gold cup parts failed at around 6k rnd from one shot to the next. I pulled the series 80 parts out and never looked back.

it sounds to me that Wilson pulled out a Series 80 part and replaced it with a Series 70 part, which would cause this dilemma, i dont see it as a problem.
you should call them and see what they say, its probably a common thing they do on S-80 guns to improve the trigger pull.

if the gun shoots fine and all the manual safetys work then dont worry about it, dont rely on the passive safety systems. as mentioned before, most people take out the S-80 safety plunger as it seems to be source for some problems. wilson prolly wont do this for liability sake.

Quoted: ...When I pulled the hammer back slightly I hear the sear slip onto the safety shelf .. ok. Now the manual says to lower the hammer to engage the safety shelf - I do that (the hammer is now sitting on the shelf slightly away from home) Now the manual says squeeze the trigger again and the hammer should fall off safety shelf - well this isn't happening - when squeezing trigger my hammer wont fall home from shelf.

The series 80 parts have nothing to do with what’s happening. If you had Wilson replace the original Colt hammer and sear with new Wilson parts the pistol is working properly. The half cock notch is capturing the sear and thus preventing the hammer from falling, just like it was designed to do. The Colt parts that came in your gun don't follow the original design and have been modified to allow the user to "decock" the gun in a “safe” manner. Not that this is even required with a 1911 but Colt in their infinite wisdom decided to redesign the hammer half cock notch to work together with the series 80 parts in order to accomplish a task that should never be preformed in the first place. Don’t worry about a thing the gun is just fine. In fact it’s better than it was before, now you have a properly designed hammer and sear.