I am not sure how long it lasts, as I give my guns a light coating every time I clean them. I have been using it for years, and have no complaints. I also use it on my reloading press and dies when I am cleaning them.
I absolutely love my BHP that I picked up a few years ago. It goes with me every time I go to the range. That being said, I certainly not get rid of my two 1911's just because I have a BHP. Both were designed by John Moses Browning, arguably the best gun designer of all times. Both designs are...
Over the years, I have picked up a couple of older model 36's. I e-mail S&W and based on the serial number, they sent me the year of manufacture. To get more definitive information, there is a charge.
This is a great looking gun, but I am not too sure I could handle adjustable front & rear sights. Being a proverbial tinkerer, I fear I would spent more time at the range adjusting and tinkering instead of shooting. Of course it would delay the fact that it was my shooting that was the problem...