I never really liked the double barrel shotgun just for the fact that it's not exactly a good modern weapon. So now all ya gotta do is make a 3d model of your single pump shotgun and replace the text in the FLDSHTGN text.

; NEW SHOTGUN

; HNDL X Y Z T C+W # X Y COMMENT
2 2041 0 0 4 0 2 0 40 -50 ;0 aim
2 2041 0 0 4 0 2 0 40 -50 ;0 aim
2 2041 -7 0 4 0 2 0 40 -50 ;1 aim loop here until shotflag
2 2042 -1 0 4 0 1 10 40 -50 ;2 fire 1st barrel,skip 11 if no ammo
2 2043 0 0 4 0 0 0 40 -50 ;3 after blast first barrel
2 2041 -7 0 4 0 2 0 40 -50 ;5 aim wait here until shotflag
2 2041 0 0 4 0 4 0 40 -50 ;8 rest
2 2044 0 0 4 0 2 0 40 -50 ;9 reload
2 2045 0 0 4 0 5890 30 40 -50 ;10 reload
2 2046 0 0 4 0 2 0 40 -50 ;11 reload
2 2046 0 0 4 0 256 1 40 -50 ;12 reload
2 2041 0 0 1 0 2 0 100 -100 ; 13 no ammo, drop down and then pop up
2 2041 0 0 4 0 258 1 40 -50 ;14 reload
-1 0 0 0 0 0 0 0 0 0 0

there ya go. where the second shot is make it coc k the gun just in case. You also have to press the button in order to coc k the weapon wich adds a bit more realisim. Enjoy