Young Buck is back in prison … TMZ has learned the former G-Unit rapper has officially begun his 18-month sentence for gun possession.
Sources connected to the rapper tell us … moments ago, Buck checked into Yazoo City Medium Security Federal Prison in Southern Mississippi.
As we previously reported, federal agents recovered multiple guns in Buck’s home during a 2010 raid. At the time, he was prohibited from possessing any sort of firearm because he was already a convicted felon.
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