I put the following guns on a postal scale with loaded magazines (to max capacity, without a round in the chamber) and weighed each of them. They range the gamut of manufacturer, size, and caliber. You may find this interesting.

M&P Shield 9MM 125GD 7 — 1lb6oz
Glock 32 357Sig 125GD 13 — 1lb13oz
Glock 17 9MM 125GD 17 — 1lb15oz
Sig M11-A1 9mm 125GD 15 — 2lb2oz
XD Service 357Sig 125GD 12 — 2lb2oz
XD Service 45ACP 230HS 13 — 2lb60z
Glock 20 10mm 200BT 15 — 2lb7oz
FN FNX 45ACP 230Ball 15 — 2lb9oz
Para-Ordnance 14.45 230HS 14 — 3lb0oz

From the lightest to the heaviest there is a 1lb10oz difference. If you throw out the extremes, the Shield and an all-steel (non-alloy Canadian P14.45) then the difference in weight from the Glock 32 to the FN FNX 45 is 12 oz.

Are you surprised? For size, weight, and capacity the Glock 17 and Sig Sauer M11-A1 are hard to beat. If you really want capacity and stopping power go u