Why Did the US Military Replace their Official Pistol?

Replace their Official Pistol

We went from the legendary .45 M1911 to the loathed M9 Berretta and now we’re switching to the new SIG Sauer pistol. Many grunts still talk about how they wish they still had a .45 pistol. Special Forces operators are rumored to frequently choose to carry a .45 instead of the Berretta.
 
SIG Sauer won the multi-million dollar contract to replace the M9 berretta in 2017. The new SIG Sauer M18 strike fire pistol has mixed reviews so far as they iron out all the problems. Let’s go over the history of pistol switches in the military.
 
Credit to : Task & Purpose