Talon SS Barrel bushing size ??????????

Hi Everybody !! Here’s my problem / story…. I was swapping out my stock Talon SS 12″ barrel with an 18″. I Thought it was easy?? (Until MY LUCK kicked in). The 18″ barrel is used (bought it from a member on here). The barrel O.D. measures about .628″ in front of each bushing and each bushing has an O.D. of about 1.13″ and it will NOT fit in my SS frame?? The stock barrel (measured the same way) has an O.D. of about .480″ and each bushing O.D.= 1.07″. So…. are there different bushing sizes OR did I get a weird set up?? Hope I explained it well and>>>> Please help !!! …. The local VERMIN seem to know my Talon is out of commission !!!
Thanks in advance,
Frank