If you know any die hard reloaders, check with them. Most folks that get into serious reloading end up getting a chronograph. One brief trip to the range with a chronograph would be a real eye opening experience. All the numbers you see on the side of the box are produced using test barrels and they don't reflect what happens in real life using real guns. The only way you can really know how fast a load is going out of your gun is to shoot it yourself and measure it.

That 165gr bullet is as light as you can get for a .45 without getting really creative like going to a hollow based bullet and creative equals custom and expensive in this case. A lead .452 round ball only weighs about 120gr. The 165gr is basically a round ball with one end squared off. The only way you are gonna get a factory round loaded with a lighter bullet (and I strongly suggest sticking with factory ammo for self defense uses) is by going to a smaller caliber.