Lets back it up, and mil spec trigger pins and  channels are .154", while some of the older colts has .170" trigger pins and channels in the receivers.  So since your Ruger uses a .154" pin FCG, make sure you have the correct FCG and pin sizes to start with for that receiver.

As for stock trigger pins, the hammer inside its channel has a J spring that will retain the pin in the receiver via an middle annual groove on that pin, while the hammer spring leg should be installed on top of the trigger pin in its side groove to hold it in place.


Also on hammer spring, makes sure is installed correctly on the hammer, so it legs are coming down and back.



Also to point out, since you have the J spring of the hammer holding the pin is place, and the hammer spring leg on top of the trigger pin, both pins will rotate in the receiver channel as the parts move.

As for the case of after market type FCG, some will come with slightly larger pins for slightly worn pin channels, and some times on a fresh receiver, do not just push in to the channels easily.  As for pin locations in receiver not being correct spacing to begin with, that one you will have to take up with Ruger.