I was discussing my choice of carry gun with my brother the other day. I'm doing a Glock 36 these days. With 7 rounds of 255gr SWC's doing about 850 fps, the thing weighs 28.1 oz.
My previous favorite carry guns are a S&W Mountain Gun in .45 Colt and a DW VBOB. They both weigh about exactly the same at 43.7 oz though the VBOB has 9 rounds and the S&W has only 6. They carry the same, exact bullets (255gr SWC's) driven to about the same speed (maybe a touch faster in the S&W).
That's why I carry a Glock 36. It is about a full pound lighter.
Then my brother says to me, "Why don't you use lighter ammo?"
Hmmmm...
He has a load which is 160gr RN (Lee mold) doing about 1000 fps over 6.3 gr of Bullseye - using Aluminum cases. Yes, I know they're not reloadable. He's loaded the same cases 3 times now though. .45 ACP "brass" seems to go forever - even when the headstamps have been fully obliterated, they still keep going.
What's the weight savings? Compared to 230 gr ball ammo, it looks like a weight savings of 2oz for 7 rounds. My Glock 36 can thus be about 26oz fully loaded.
I'm not switching carry ammo any time soon but I thought this was intriguing.
FWIW