I have a RRA lower I bought with a 6 position collapsible stock that I'm converting to a Magpul PRI stock. I ordered a new tube, buffer, and spring for the conversion. The PRI stock came with a screw to secure the stock to the back of the tube.

Here's the odd thing, the hole in the back of the tube I ordered and received from PK is NOT threaded. Is this normal? I thought all A2 tubes were threaded for the mounting screw.

It's kind of annoying. I have everything to assemble and everything fits, but I can't complete the assembly because there are no threads in the hole.