This is a model of the Pipe Pistol from Fallout 4.
Warning - The assembled model (the actual STL model) is much bigger than it should be, if you want to print it (Only the already assembled model, the part models are sized correctly) you should shrink it, i can't remember what i shrank it by so i'd test between 80-60%
I printed mine in copper and wood fill to get a very real look to it.
Most parts are modeled together with a very small bridge, this bridge will not print (you don't want it to) unless you have a layer height of something like 0.001mm so don't worry about it.
the barrel is over 300mm long so if you don't have a large printer you will need to cut the model and this should OK, there shouldn't be anything wrong with cutting models and gluing them together after. This goes for all the parts if they dont fit your printer (although the spring may not cut, idk)