A SECRET WEAPON FOR UNDERSTANDING DIFFERENT CALIBERS OF HANDGUN AMMUNITION

MoCo Bought a rifle that can take AICS mags. It arrived w/ 1 PMAG10 AC. Thats quite long if making use of susceptible (TIL AICS mags are solitary stack.) I want to purchase some 5rd versions. Seeking online I observe magpul has new 'Sig Cross' versions w/ a follower that has slightly feed lip at the front to help if loading singles through the ejec