What difficulty?
Independend on that, the legendary weapon system is a bit broken / bad design decision. Your shotgun shoots multiple pellets and each pellet of that creates the bleeding damage of 25 on all body parts affected.
Try changing the game difficulty to very hard or survival if you are under level 50 and try it again
8 pellets give you 200 extra damage, its DoT probably 5hp over 5 seconds. with max rifleman shotguns can do 160 by themselves I would prefer two shot in one then fully perked, a less damage but instant effect.
Not giving shotgun the effect for all pellets would be a bit hard as not everyone might hit, it would also be an nerf compared with automatic weapons.
My personal sidearm is a Sawed-Off Double Barrel with the "Fiery" perk.
I was experiencing the same thing (it's "only" 15 fire damage per pellet though), playing on Survivor and took down Mirelurk Queens by the dozen. Until I chose the "Penetrator" perk. With it, it will randomly glitch out and hit for barely an inch of health, despite being displayed as a one-hit kill at point blank range.
Do not chose Penetrator if you like shotguns until they fix it; I'm still contemplating to go back multiple days in game time just to undo it. Made my signature weapon absolutely unreliable.
Fire damage does not stack with itself, you only get 15 damage no matter how many pellets hit.
Note, all bonuses except irradiated and explosive* are boosted by the relevant weapon perks. Irradiated is boosted by Nuclear physicist, and explosive by demolitions expert, heavy gunner also boosts the explosive damage, which allows the minigun (only heavy weapon that can get explosive), to deal 4x explosive damage.
I guess the game thinks that you are part of Hell's Grannies the most feared gang in the Commonwealth.
Are you selling them? I store all my legendaries and the game seems to do a good job on variety when I get a new one. Very few duplicates too. Maybe 1%.
had the same problem with a 2-shot shotgun. increased difficult to very hard, and eventually survival. problem solved.
Sounds a bit like Fallout 3 shotguns who added the sneak attack critical bonus to each pellet. This was an bug, an sneak attack from an shotgun should not do 8x damage from other weapons.
The legendary effects are far smaller 25x8 or 15-30x8, now if two bullets added base damage of weapon to each pellet that would also be an bug.
Explosive minigun benefit from both the explosive and heavy weapons, fatman and missile launcher works the same way so an fully perked fatman does over 1800 damage.
Explosive minigun does +70 from each bullet fully perked, its OP so I recommend increasing reload time (never had to reload during an fight you run out of enemies long before)
im playing on survival... not too much difficulty for my 2-shot-gauss-rifle with 760 damager per hit (not considering crit, sneak, concentraded fire or gun fu effects etc...)
dominatrix assaultrons are still a [censored]
Institute Coursers disagree. lol.
Although my Bleeding Shotgun comes in handy, it never 1-shot kill these bastard aimbots.