Originally Posted by John_Deer
There are so many 1911's of various models I have a hard time believing one grip safety fits them all with just a little filing.
Here are two RIA 9mm 1911's. You can see the tactical model is designed for the shooter to engage the grip safety with his off hand.
Have you ever changed the main spring housing or added a mag well to a 1911? The bump you are referring to has no bearing on the length of the grip safety.
As previously stated, to install a garden variety beaver tail on a GI model requires grinding on the frame where the grip safety pivots, but not where it meets the mainspring housing. A little filing, maybe.