I looked around on the nexus and only found 1 rather unknown mod that added them. In real life there are shotgun slugs that are like a miniature version of a 40mm grenade and can turn any slug shooting shotgun into a mini grenade rifle. The explosion would be smaller than a 40mm, and weaker.

I tried to figure out how to make one in the GECK, but could not figure out how to do so. I would either like some tips on how to make exploding slugs. The only thing I really need to figure out is how to make a projectile explosive and act as such. I would use the same shell model and projectile model and only need to make the slug explode and deal at least half or more of the damage the shotgun does in an AOE, and the rest on direct hit. I am a novice as far as the geck goes. I can change values on item stats and game modifiers and stuff like that, but do not know how to make a projectile explosive.

edit: After some research I found that 1 foot radius in game is 21.34 game units. Now I need to decide how big of a blast radius is reasonable. I will go do some research on the real thing for reference.

Edit: after research I found the rounds I saw are known as Frag-12 rounds with a lethal blast radius of 2 meters so I would say 260 game units blast radius would be appropriate for 12 gauge. Now I need to decide how to figure out a proportionate blast size for a 20 gauge shell so I can use my sturdy caravan shotgun with frag grenade rounds on my explosive character.