I have a centefreed 223 magazine that I am trying to take the spacer block out of. I can get the magazine disassembled but can't get the little block out. It looks like there is some type of rivet on the rear portion of the metal mag body. Does this pass through the spacer block as well. Or am I doing something wrong. Any help on trying to get this out will be great. I am wanting to put a 7mm tcu barrel on but my loaded rounds are too long for the 223 mag. They will fit without the block in the back. Or does anyone have a better suggestion for mag feeding a tcu rounds. Thanks