So I finally got a set of flip sights and a carry handle for my M&P and need to get them sighted in. What do you guys use to adjust the front sight.. Should I just buy the tool? Use a pic ? A friend of mine said they used to use a spent casing that would fit over the sight post on their service rifles but doesn't look like it will fit in the space on my flip sight . Anyone have any good tricks?? I got a tool yesterday but doesn't seem to work, the only one they had in stock was a cheapy and now I see why.