u/Any_Elk_9505

So I got one of the $100 PSA AC Unity Alfa kits and I'm wondering about the BCG compatibility with the Maxim RDB.

So this bolt is a little strange. It doesn't have a center weight and the rear of the BCG is hollow, but its undersized from what a regular 9mm bolt usually is (just visually comparing them).

Can anyone tell me what diameter the center rod of the RDB system is so I can measure and compare to see if one will even fit through?