There is no lightweight pistol that I enjoy shooting. Everything I own , except the Nano, is all steel or alloy/steel. The heavier pistols are easier to shoot, the lighter pistols make better pocket guns. My Sig P-6, at 2 lbs loaded, disappears in a Crossbreed supertuck, and I can carry it all day comfortably. For waistband carry , thin is probably more important than weight, hence the popularity of decent sized .380's .
3d Infantry Division
Beretta 70 Collection