I'm trying to install the spring that goes between the trigger and the disconnector. It seems that one side of the spring is a larger diamter than the other. So large that I can't fit that end down into the trigger. So I put the smaller end in the trigger and it fit fine. When I tried to install the disconnector on top, I couldn't get the pin all the way through. The spring's larger end now blocks the disconnector from going far enough down to get the pin through.

Am I correct in thinking that this spring is defective? Or am I supposed to jam the large end down into the trigger?

Also, is there a specific direction the trigger and hammer pins need to go in? They aren't symetrical, and I don't see a clear direction they should go.

Thanks!

Wait, i think I found it. There's another spring that does fit. Is the spring with the one larger end supposed to be the bolt catch spring?

the spring with the one larger end goes in the trigger....you sometimes have to force it........the smaller end goes in the notch in the bottom of the disconnector..........the spring thats about the same size but both ends are the same diameter is the bolt catch spring.

jam it.

Ok thanks. I managed to put almost everything together.

I'm having trouble with the bolt  catch.  It seem like it won't sit far enough down into the lower to get the roll pin in. I can lightly hammer it down further, but then it get's very tight and I don't think it would operate correctly. Is this normal? I would guess that the part is a bit out of tolerance.  There are marks where it seems to be hitting the lower.  How should I handle this?

Quoted: Ok thanks. I managed to put almost everything together. I'm having trouble with the bolt  catch.  It seem like it won't sit far enough down into the lower to get the roll pin in. I can lightly hammer it down further, but then it get's very tight and I don't think it would operate correctly. Is this normal? I would guess that the part is a bit out of tolerance.  There are marks where it seems to be hitting the lower.  How should I handle this?

Take out the spring and plunger for the bolt catch.  Now, insert the bolt catch with no spring installed.  Can it line up easily?  Does it move freely when lined up with the roll pin hole?  If not, then get some fine sandpaper and remove metal/polish the bolt catch surfaces, and ensure there are no burr's/raised edges in the lower.

I took the spring and plunger out and it doesn't move freely. Its almost impossible to align without  hammering it in.

I examined the lower, and it seems to be clean. I tried the bolt catch on a second stripped lower I have and it didn't work there either. It seems to point the the bolt catch itself, so I'll try the sand paper.

Thanks.

Yep, those are cast/MIM parts... and not always in spec.  you can sand it, or call who you got it from and they will likely ship you out a replacement for free.