Hey guys, i just found the Ratslayer nothing special about it.
But when i looked it up on fallout wiki it shows a scope, extended magazine and a silencer. So i looked up on Youtube and saw the same.
Now the thing is, mine is just a standard one without scope, extended magazine and silencer :S has it been changed in the patch or something?

Do you, by chance, have Weapon Mods Extended (WMX) installed? That removes the initial modifications uniques have, but you can add them back in yourself later.

Ah yes i have, okay good to know i can add them back myself later then. So if i buy a normal rifle scope then it will change to the looks of the ratslayer's scope?

Most likely, the look of the accessories are dependent on the weapon it's attached to.

Yes, a rifle silencer, rifle night scope, and Varmint rifle extended mags are the three you can put on.

You'll have two notes in the Data/Misc section of your Pip-Boy that detail what guns have what mods, and what mods can be applied to what guns. Some aren't quite as obvious as the Ratslayer's.

The best thing about the Ratslayer is the 5x criticals. Not there for the varmint rifle with the same stuff.

Ratslayer + Finesse + 10 Luck

Critical hits are not not possible.

Indeed it can be a very powerful weapon. Light, accurate uses common ammo that comes in both HP and AP among others and looks quite fine in my hand. I rarely use the sniper once I have the Ratslayer. I like to wait till I have 'friend to animals' then go loot all those animal caves. It's nice to just wander in, compliment the local boss on his wonderful children and leave wit da goodies.