since you asked for a favorite cartridge and not the most effective for hunting or self defense i had to say the lowly 22.
the 22 was my first handgun caliber. the 22 comes in a variety of handguns including single action and double action revolvers and just about any type of semi auto including copies of 1911 45's. you can shoot 22's in about any type of gun that mirrors your favorite centerfire handgun making you a better shot.
the 22 is a favorite for many types of small game and i hear it has been popular with poachers for a hundred years on larger game also. it can be used on birds when needed without calling foul. it can also be pressed into service as a self defense gun with good results according to statistics. i have even read that it has stopped more than a few big bears although i'm sure there were prayers involved and a change of underware.
so if you shoot 44mags or 45 acp, revolver or semi autos you can find a similar gun in 22 and become a better shot for less money and have a hell of alot of fun doing it.
Has to be .45ACP... with the .41Mag as runner-up. 'Self defense' is what keeps .45 at the top of the list. Easy to load, easy to shoot, easy to find components or loaded ammo.
Probably my favorite round is the .44 but it's spendy and I don't reload, nor do I use it for CC. As mentioned it's a very versitile round. So it would probably get the nod.
.22 is by far the cheapest and I shoot more .22's than anything year in and out.
I like the .45 round for it's proven track record, recoil isn't bad and the Semi Auto I'm most accurate with is a FS 1911.
I had avoided 9mm for quite some time and now feel that I made a big mistake in doing so. Cheaper to shoot, lower recoil, I'm accurate with it and can get my pistol back on target with it quicker than all of the above mentioned except for the .22
9 mm is a nice combination of controllable recoil and effectiveness on target, and its low price is a bonus. If I have to pick just one, I'll stay with that.
Though I do not own one, yet, I voted for the 10mm, it is, IMO, one the most versatile cartriges ever developed! Also, if it is too BA for the FBI than it should be just right for us normal citizens.
That's weird to me. .357 kicks but, and you can down load to .38s.
First, I have great repect for the big fat slow bullet, but the .357"mag is a ripping powerful bullet. We would have won WWII if we had that, ohhh, what, never mind.
Tough call between the .22lr and .357 for like many I shoot more .22lr than anything else. The decideing factor for me was I can still have long guns so I still have .22lr rifles for plinking and hunting.
Edit: Changed my mind and vote. If I had to sell all my handguns cept one I just can't imagine selling a .22lr before the .357. A .22 would be last to go.
10mm out of a 6" barrel can generate slightly better velocities (well over 1,500fps), using slightly larger and heavier bullets (40 cal 165grn vs 36 cal 158grn), than a 6" 357mag revolver so that it generates considerably more muzzle energy. Plus one can carry 3 times the ammo load in the pistol and ready to use than a revolver.
Plus it has a significantly lower felt recoil impulse in a flexible polymer frame that soaks up much of the sharp recoil which makes it much, much more controllable than either an 357mag, 44mag, or 45colt revolver loaded with hot ammo.
I subscribe to the adage that it does no good to have significant muzzle energy if you either can get a follow-on shot because of the huge muzzle flip or you run out of ammo before the threat is neutralized.
Specifically, I would load hot 10mm ammo in this .................... come to think of it, I do: