I've reviewed tons of pictures on this and other Forums and cannot figure out the correct way to put in the Pivot Pin in my L1A1. Does the slotted half face the ejection port side or the charging side of the firearm? Or does it not matter? Iv'e seen it both ways in all the pictures and even both ways in some pictures of multiple firearms from the same owner. Mine fit's either way. Just want to be correct. Thanks.