Hi guys. After my transplant of a s310 top part action on to my s300 i cannot get the magazine i bought to rotate. The cam is working when you pull the bolt back and rising the springy thing that rotates the mag up with no magazine in the gun. But as soon i pull the bolt back and push the mag in to place the brass spring that rotates the mag stay at the top so mag will not rotate. Either the mag i ordered off ramsbottom bottom is not for this gun as stated or i am missing something. Its been 15yrs since i had my proper s310 so maybe i am doing something wrong? I dont thing its the mag as ramsbottom said it is for 310/410/510 and the new bullpup. Help please. Regards. Chris