If you'd like to have GTA V stats for the shotgun, here's some stats I made using GTA 5's weapons.meta file (GTA 5's weapon.dat) 

Open up Weapon.dat with notepad and replace these 3 lines with mine:

$ SHOTGUN			INSTANT_HIT	30.0 35.0	349	-1		3	shotgunbad	8	 26		0.82 -0.02  0.23        0  0	1.0	 1.0 	 6 40  7	 6 40  7  28	2021
$ SHOTGUN			INSTANT_HIT	35.0 35.0	349	-1		3	shotgun		8	 29		0.82 -0.02  0.25        1  200	1.2	 1.1 	 6 38  7	 6 40  7  20	2031
$ SHOTGUN			INSTANT_HIT	40.0 35.0	349	-1		3	shotgun		8	 29		0.82 -0.02  0.25        2  999	1.4 	 1.3 	 6 38  7	 6 40  7  25	2031



These stats aren't 100% like GTA V's stats, but it's pretty close.

Have fun.