I shot my RFB for the first time yesterday and found that the factory mag would not allow the rifle to feed if there were more than 2 rounds in the mag. Unfortunatly it was the only mag I had with me so I just loaded 2 rounds at a time to set up my optics and get the gas system adjusted. Love this rifle !!! When I got home and cleaned it , I threw a fully loaded polymer mag from my RRA LAR-8 in it and hand cycled everything thru it without any issues. I apparently got a bad factory DSA mag. Any reason why it would be unsafe to run the polymer mag in my RFB ? I put a call in to Kel Tec this morning but noone has called me back.