[Blackgryph]

I recently bought a new rail to replace the one I had on my gun. The old one had a part that screwed on to the gun that tightens the barrel in place. It had the 20 holes around the circumferince that the pins go through. The old rail had a peace in the end with two holes to line up with the pins, and a peace that goes over the hole end and tightens the hole thing together. The new one came with a peace to go straight on to the gun. this peace has the 20 holes around the circumferince and is threaded around the out side. The new rail is threaded on one end to screw right on to the peace mounting to the gun. There is nothing that came with it to line stuff up. When I screwed this all together, the rail didn't line up with the upper rail.

So I guess my question is has anyone used tone of these before? and if so what am I doing wrong/missing? This is the first time I've worked on an M4. Up till now I've only worked on Ak's, G36 and one M14 Shudder.