Bulb life is 'questionable' at best. 1-1/2 to 2 months can equate to 1080-1440 hrs, if left 'on'. Switching on/off affects life, as do vibrations.
Dimmers extend bulb life somewhat, as the ramping up, as opposed to the 'jolt' of full-on is 'gentler' on the filaments.
Lastly, ....bulb brand and 'lot' can drive you crazy sometimes.
130 volt bulbs do last longer, lumens are a little less....