▁single - action ▁target ▁version ▁of ▁the ▁Model ▁ 6 4 5 , ▁with ▁a ▁match ▁bar rel , ▁Nov ak ▁sight ▁( an ▁adjust able ▁rear ▁sight ▁was ▁optional ), ▁an ▁adjust able ▁trigger ▁stop , ▁st ain less ▁frame , wal nut ▁g rip ▁pan els ▁and ▁bl ued ▁slide . ▁It ▁does ▁not ▁have ▁amb ide xt r ous ▁controls , ▁but ▁does ▁have ▁a ▁half - cock ▁safety . ▁The ▁p istol ▁is ▁roll mark ed ▁" IP SC ▁ 1 0 th ▁An ni versary ▁ 1 9 7 6 - 1 9 8 6 ". ▁ ▁Smith ▁& ▁W ess on ▁changed ▁its ▁number ing ▁system ▁with ▁the ▁introduction ▁of ▁its ▁third ▁generation ▁iteration , ▁where ▁a ▁four ▁digit ▁numer al ▁replaced ▁the ▁earlier ▁three ▁digit ▁numer al ▁design ators . ▁ ▁One ▁of ▁the ▁first ▁in ▁this ▁series ▁was ▁the ▁ 4 5 0 5 ; ▁this ▁is ▁essentially ▁the ▁ 6 4 5 ▁with ▁only ▁the ▁safety ▁catch ▁amb ide xt r ous ▁and ▁a ▁bl ued ▁finish . ▁A ▁Nov ak ▁Lo - Mount ▁rear ▁sight ▁was ▁installed ▁on ▁a ▁small ▁number ▁of ▁ 4 5 0 5 s . ▁It ▁was ▁produced ▁only ▁in ▁ 1 9 9 1 . ▁The ▁Smith ▁& ▁W ess on ▁Model ▁ 4 5 0 6 , ▁is ▁made ▁of ▁sat in ▁finished ▁st ain less ▁steel , ▁a ▁Nov ak ▁Lo - Mount ▁rear ▁sight ▁later ▁in ▁the ▁series , ▁and ▁a ▁X eno y ▁wrap