I'd guess it would be one of the deringers similar to American Deringer's Model-1 which weighs 15 ounces. In a semi-auto it might again be one made by American Deringer, their LM4. AMT made their Backup in 45 ACP which weighed someplace in this range also. I don't imagine there are too many lightweight revolvers in this catagory unless S&W makes a scandium or titanium model. Then I would expect it to weigh under 30 ounces.
Also looked at the lm4. I wondered what ever happened to that
Simmerling. It seems to me though that it wasn't an auto. Something in
the back of my mind saying it is some kind of manual action,
that requires some sort of pump action to cycle it.
I have got interested in light guns recently after having just
bought a Keltec p3at. I wanted something that was so easy
to carry as to be as near unnoticeable as possible. My
previous light weight has been a Star PD. This is quite a
nice little package. It is actually lighter than many 380
autos, even though its a 45. It weighs 25 oz with empty
magazine. Surprising, it is very comfortable
to shoot. The only thing I have found to fault it, is the safety.
It can dig into your side when worn close in. After getting
this new Keltec, with no manual safety, it got me to thinking,
too bad, Star didn't make the PD with double action and
no manual safety to dig into your side.
The Keltec is nice shooting also. I had an AMT backup
in 380 for a number of years, and I hated shooting it,
it was so uncomfortable, not that you shoot one of these
types of guns often, but I tried to cycle a box through
it about once a year.
Another thing that comes to mind here is on the Star PD.
As I searched for a picture of it, for this post I came
across references to guys using a shock buff in these
guns. I have never used one, and I am curious, as to
where you would put it. Can some one tell where it
would go, possibly using one of the pictures in the above
link to field stripping, to describe where a shock buff
would go, if a colt 45 type would fit in it somewhere.
Ooooh, look here. A Glock 36 weighs 22 1/2 ounces.
and the Para ordnance p10-45 goes just 19 oz
according to this:
My first 45 ACP was a Star PD and I shot that until the frame cracked. Mine was 28 oz actual but still pretty light. I didn't mention it as you did ask for "in production" which I took to be currently being produced. I have no idea how the shock buff would be inserted, it has been a couple of decades since I last saw a PD close up and can not remember what it looked like inside.
I am not familiar with the Simmerling, I saw one at a gun show and that has been it. I think the AMT was a manually operating gun now that you mention it. I knew one guy who had one but never had the opportunity to even handle, let alone shoot it.
I have a 45/70 deringer that I bought a spare set of 45 Colt barrels for. I carried a 357 deringer in a boot holster for years until I found someone who wanted worse than I did.
I did not even look at Glock as they just do not like me in any way and the P-10 I shot sure felt a lot heavier than 19 oz but maybe its so.
I have a Kel-Tek P-40 that I carry as a summer gun and as a back up gun other times. It is actually quite pleasant to shoot and with the 8.5 spring, trigger shoe, and a buffing of the sear and internals it is a pretty accurate gun. I have the magazine extensions on the two standard mags which give them 10 round capacity. I also have two 12 round mags on order, they fit flush with the grip which will be interesting to try. I also found the Houge slip on grip to effectively help contol the gun. All in all I think the Kel-Tek is a lot of gun for the money.
I like the look of this Patriot gun. Appears to be a very good size
for covert carry, and looks like it might be comfortable to shoot,
judging from grip shape. How does it work in actual practice?
Again, a nice looking small package.
It shoots pretty well. has a bit of "bite" with defence loads but still very controllable. With the mag in it my pinky finger doesnt hang off. Oh yea, and it can take standard 1911 mags! sights aren't the best and gun isn't super accurate but its accurate enough for its intended purpose. It is DAO, has a heavy triger pull, no safety or slide stop and recessed mag release.