I have 4 Tapco's, i had i FTF on the last round. I only shot 1 30 rd mag, and 1 20, and 2 15 rounders (I was just trying to see if i needed a bullet guide) I am not using a bullet guide, It has the flat trunion. i did absolutely nothing to make it fit in my rifle and they fit great. i am very happy to have bought these.