Top and bottem reciever
 

Hey first of I didn't know where to put this. Just got a question today was working on my friends g&g predator and I'm having a head time putting the top and bottem reciever together as things look I'm going to have to use a hammer to get it togther. I compared everything to my own predator (which is a little tough to her together but not to bad) and I can't see any differences. Question is is it normal to be that different

There's usually some wiggling involved to get stuff aligned on tight toleranced receivers. You shouldn't need a hammer.

Your hop up chamber might not be sitting flush and preventing them from coming together properly. Put down the hammer and examine it properly before you break anything.

So I took a look at it last night and the hop up looks fine. I can't see any differences between the two. Also I can't see anything catching when I slide them together. It's the last 1/4 inch. It's like it's hitting a wall

Is the hop up going onto the nozzle of the gearbox and not INTO the gearbox? Look from the magwell.

Post some pics.

faux bolt or charging handle in the way

So took same time today to finish the gun. The issue was the spring from the stock hop up stayed in the gun then when I put the new one in I used a but of glue to hold it in place. So when I was putting it in the 2 spring collided and didn't allow it to move ahead that tiny bit. Pulling the old one out and now it works