I have a Bulgy 74 kit I am finishing up as a screw build on an OOW receiver and have run into a couple of problems.

Problem 1:  I can't get the selector in.  I know I have to remove the tab on the bottom of it so it can get past the disconnector.  That's not the problem.  There are two other things going on.  One, the screw next to the selector hole is too close.  The edge of the selector hits the head of the screw.  Unfortunately, I have already Loctited the screw in place.  The rear trunion seems to be in the right place.  The top cover snaps in nicely (that's why I went ahead and Loctited the screw-everything seemed to be fine).  To try and solve this I have been grinding down the back edge of the selector.  This has allowed me to get the edge of it away from the head of the screw but it still won't go all the way in.  I don't know why.  It won't go in far enough to let the groove that is cut in the selector, that would rotate around the wall of the receiver, from going in far enough to rotate downward.  It seems to be baaaareeely missing enough room to do so.  I'm afraid to simply enlarge the groove because I don't if the selector will be fully in its hole on the left side of the receiver.

Problem 2:  I can't get the bolt carrier to go forward unless the hammer is held down by the disconnector.  When the hammer snaps up into the cocked position the carrier will get  stuck behind it.  My S/A trigger kit came with an "extra" piece that I didn't know what do with.  It's a bar that is bent in a rounded 90% angle.  The instructions for installing the FCG that is linked to the BIY forum doesn't have such a piece.  All it has is the trigger, disconnector, and hammer assemblies.  Could this be the problem.  Or does it have something to do with the selector not being installed.  Or is it something else.

If any of these problems sound familiar to anyone out there please help.  Thank you very much.

Edited : I fixed Problem 1 with a little grinding but still have Problem 2.

I had all these things come up on my 74 build,   I ground off to just 1mm shy of the outermost ridge of the rear of the selector and from top to bottom  so I could put it in and it would rotate freely up and down without rubbing the screw. Also its got a hole it has to go through on the other side so everything has to line up just right, if it is bumping that screw at all at that point it wont go in.  I also had to cut down the  safety lock on the inside bottom of the selector so it would work and move over top the trigger. On problem 2, mine would lock back somtimes went I first assembled it but I noticed the hammer and had a rough texture to the face of it so I polished it up and put a little oil on it and works great. There is also a front angle on the bottom of the bolt carrier that had some rough spots that polished up as well and made it even smoother.

CZ75, thanks for your reply.  I got the selector working with a little grinding and polishing. I'll try polishing the hammer and bolt face today.  Thanks again for your help.

did anyone have this problem, the rivets on the front trunnion of my bulgy were already flat...and it looked like someone had already tried to start drilling them out....and the holes were way off center!!!   gonna be a serious pain to get these out

I saw a Bulg 74 kit at the gun show this past weekend that looked just like the way you described, with the off-center drilling. I didn't buy it because I thought someone had already messed with it.