MANY years ago I formulated a mixture of lube for my semi-auto handguns because I was shooting a Commander LW and an early Colt SS 1911, both of these units could have gulling problems if not properly lubed.
I tried many lubs and combination of lubs and came up with one which really works well!
I took a 4 oz bottle of Break Free and emptied out 1 oz and replaced it with 1 oz of STP oil treatment. I use just a 'drop' on each side of the slide. I mixed this bottle in about 1978 and I still am using this same bottle. A little goes a long way!!!