Concern for 9mm block hurting receiver?
I'm thoroughly confused on mag blocks. I've read about the set screws on the bottom loaders damaging the lower. I wondered it that was a real issue, and if the Hahn top loader has a screw as well. I understand I would lose the Last round hold open, but I'm willing to sacrifice that for the RR safety.
Also, best buffer for 9mm and 223? Will the heavy buffers run both?
no idea on question 1
Question 2, I run a Spikes ST-T2 buffer with a standard spring, also a 9oz really heavy buffer with an extra power spring. They both work, it just depends on what I'm shooting. For lively 124gr NATO I go with the heavy combo, but for lite target rounds I go with the Spikes and standard spring.
My hahn top loader has a screw in the block that pushes a roller against the inside of the magwell. It uses a very thin allen key (comes with it), which would make it pretty hard to hurt something. I just snug mine up, and it's never come loose in three years.