The main reason I'd want to try to blue is to give it a more natural-than-what-it-has-now look, but mainly to see the quality/composition of the steel body. If the steel used is cheap and lacks iron, the bluing won;t catch and it's one way to indicate toward specialty or cheap steel...and bluing a patch on the inside receiver is a lot better and cheaper than trying to stress test the frame, or cut a chunk off and have its chemical structure analyzed. Also, as stated above, we all know that NOBODY EVER has decided to veer away from a factory finish
On a semi-related note to all this, the unseasonably warm weather here in Ottawa means that I'll be making and uploading a video of how this baby shoots. Total round count so far: 540 with
0 failures to feed or cycle, and functioning bolt stop on all magazines fired.