As a proud owner of a Ruger AR 556 model 8500. The Magpul 30 round will fit and function fine. Along with Magpul 40 rounder and any other 30 round magazine out there. It will take them all.

William, yes Sir the Magpul will fit the Ruger AR556. Any standard AR Magazine or Drum will fit the Ruger AR556.

Ah now we have information! thanks William - yes sir, the Magpul 30 round Pmag will fit - will fit like it was made for the Ruger .. because it was! :-)

these will fit budsgunshop.com/catalog/product_info.php/products_id/712006547/magpul+pmag+m2+moe+magazine+ar-15+223+rem%2f556+nato+30rd budsgunshop.com/catalog/product_info.php/products_id/718001641/magpul+pmag+30+round+ar-15+w%2fwindow+gen+m3+black budsgunshop.com/catalog/product_info.php/products_id/714003461/magpul+mag234-blk+h%26k+g36+pmag+30rd+223rem%2f556nato+black

William - Sir you did not identify or name any certain magazine, but if it is a standard AR-15 magazine or drum, it will fit the Ruger 556 rifle