New build, BCG fails to move forward into battery

[Jeffpatton00]

I had a smith, Joe Carlos in PA build, a 224V upper for me, and I really like his work, but when I mated it to my existing lower I ran into a problem - when I press the bolt catch button, the BCG fails to move forward into battery. Curiously, if I apply pressure upwards between the takedown pins but downwards on the buttstock and handguard, the spring will move the BCG forward (basically, lightly forcing the rifle into an arc). There seems to be interference where the upper mates with the lower, preventing the buffer from moving the BCG, and when I put that "bend" on the assembly, it releases whatever is interfering and allows the buffer to move the BCG. I haven't had time to troubleshoot this, but would anyone have any tips on where to start? Once Washington's "non-essential Governor" lets our ranges re-open, I'll want to begin load workup so I need to figure this out. thanks

 

[Liberator]

Check that your gas tube isn't hitting the bolt carrier. Mag.,or no mag. ? Check proper function of buffer. Is it binding ?

 

[ShtrRdy]

Did the BCG come with the new upper or are you using a BCG from another rifle? If it came with the rifle I would think it would work with the gas tube.

There are a few other things that could prevent the BCG from being released by the Bolt Catch. I think the first thing i would check is to see if the Bolt Catch is moving freely and that it can drop all the way down into the lower receiver. Check this by looking at just the lower receiver and the movement of the Bolt Catch.