CCW choice

it's a good little gun, but you've gotta tighten up those groupings, son.

You're either trolling, or trying to ask about the effect of barrel length on shot accuracy in a very obscure way.
If you do mean accuracy, then the stuff I mentioned about recoil comes into play, since with most pistol cartridges you'll need follow up shots. There are also issues about chamber pressures to fully accelerate the bullet, and would also be dependent on the ammo load and cycling action.
TL;DR
It would be snappy, and I wouldn't be counting on it to engage a threat on the other side of a parking lot.

I'd suggest tightening up on practice regime too.
How do you accurately tell how much you've improved by in 6 months if you're hand drawing a target on scrap?
If you're poor fag, get some wallpaper on sale and make a simple target stencil out of card. You can draw large targets onto the plain white back of the wallpaper and cut them out or hang them up.

So a subcompact pistol chambered for either of those rounds would actually make sense, is that correct? Of course, it would have limited utility, but in theory they should be about as effective as .357 Magnum. Or at least the data here suggests that:
ballisticsbytheinch.com/357mag.html
ballisticsbytheinch.com/357sig.html
ballisticsbytheinch.com/10mm.html

No, I'm asking about the ballistics of 10mm Auto and .357 SIG out of a 80mm barrel in a rather direct way.

Small changes in barrel length may not change the terminal ballistics that much, however more extreme barrel lengths can change it quite a bit. Maybe you won't see much difference between a 2 inch and 3 inch, or even 4 inch, but at some point performance will change as the inches of the barrel increase. Its a complicated issue, though.

Certain cartridges have vastly different internal ballistic properties. I carry a 357 Magnum in 6 inch barrel, and its quite the cartridge in this regard, the difference between the average 4 inch barrel revolver and 18 inch rifle using the same 357 and 38 Special loads is about DOUBLE. One looks at the data and it appears these cartridges are far more sensitive to barrel length; other pistol cartridges see moderate gains from longer barrels all the way up to absolute near 100% optimization.

This can be considered good or bad, good in the fact you can rest assured that the terminal performance of your compact pistol isn't going to suffer much for choosing the smaller barrel. It also can be viewed as bad because it reduces the gain from using a carbine in that cartridge. Strong loads of 158 grain bullets in 357 Magnum can acheive upwards of 1,350 fps in 4 inch revolvers and 1,850 fps in a rifle, doubling the energy, the rifle now is an ethical choice for short range deer hunting. A longer barrel 9mm carbine is definitely an advantage, but no where near the gain (nor the loss) of the 357 Magnum.

This might be a bigger issue in high power, higher case capacity cartridges rather than smaller ones. Still, the evidence is there that short enough barrels might effect killing ability, so you should do your research on your particular gun, loads desired to shoot, barrels, learn a little about the hicks and kinks of your particular cartridge.

THEN we have to consider that various guns will have different characteristics. Even with similar barrel lengths wear, tightness, action, all play a roll in performance. Cylinder gaps in revolvers play a crucial roll. I think either Speer or Sierra did tests on magnum revolvers that after 6,000 rounds of high pressure full power loads revolvers would lose an average 100 fps for life from throat erosion and wear. The idea that your old beat up Glock will have lower velocities than you brand new shiny Glock of the same model is not an insane one.

Follow up note is that longer barrels are easier to control. You change the axis to your advantage, you reduce muzzle blast's effect on pushing the weapon around, you push it further away from you. All of this leads to better combat shooting by way of making the firearm easier to control. Yes, one can shoot a high power short barreled gun quickly in some cases, but it takes everything the man has to attempt to control it, both hands, his full weight and effort; not all of these things are available in combat. The longer barrel gun offers better control when wounded, tired, in a poor position, weak, injured, one handed shooting which easily happens in real life.

This makes full frame pistols and revolvers superior, in every aspect save for perhaps weight and totally in concealment. The bigger, heavier, longer gun has better control, ballistics, lest blast, recoil mitigation, and often capacity. These are facts. You want to carry a very concealable gun, that's fine, just keep in mind the objective facts of the field.

At some point my Hi Power is better in a carjacking situation, where you are shooting weak, one handed, out the side of a window, than a micro 9mm Luger. My full size 1911 is superior to a compact 45 ACP in the same scenario. I can control my 6 inch barrel M-27 pretty easy in that situation, not as easy for someone with a snub nosed lighter weight smaller framed 357 Magnum.

Last note of value is the dreaded undergun followed by underload syndrome. Johnny buys a super lightweight snub nose 38 Special rated for +p ammunition. He says he will carry +p high end ammunition. Johnny shoots the high power ammunition and gets sick of the blast and recoil. Johnny downgrades and starts to shoot light load 38 Special regular pressure. Johnny doesn't simply just have a small barrel, he has a light load to go with it. Soon he is shooting weak rounds and should just stick ot non expanding ammunition just to keep it from under penetrating.

My big boi revolver and all its heavy weight and long barrel makes it suitable for the most hottest powerful 357 Magnum loads that can be loaded and fired. The point is firing super hot loads of 357 Magnum is more comfortable, and more controllable, in my big revolver than light loads in Johnny's snub compact ultra light. Johnny made a good decicion on a good gun, I recommend the old J frames, but the point stands; those of us who carry full size can control full power rounds better than gutted rounds in smaller guns.

Concealability does in deed come at a cost.

Faggot that's been CC-ing an SP101 .357 with babby-tier 2.25 inch barrel for the better part of a decade here.

Would just like to add, with enough training you can, you really can, overcome all those issues. "Enough training" in this case meaning "seriously tens of thousands of rounds and combined totals of months of practice", but it can be done. I can reliably nail targets at the medium rifle range at my gun range with the SP but I had to shoot it a truely insane amount in order to get to that point.

In the amount of time it takes you to git gud with a snubnose revolver you could git olympic-tier with virtually any other type of gun. Same goes for reloading. I can reload mine FAST, but that's only because I've A) gotten it chamfered and B) gotten it down to muscle memory I've done it so much.

I've also never really had trouble with the muzzle blast. I always hear it's blinding from a snubnose but good god I have never ever noticed it being any worse or better than any other gun after shooting it a shit-ton. Maybe that's just me.

Do you shoot better than that at 25 yards with a sub compact .45?

yes, but tbh don't go for subcompact, it is shit-tier in generally because sub 4 inch barrels is where you really lose performance across the board. Stay with a 4" barrel compact gun like the Glock 21, the p229. Glock 29 would work as long as you're carrying real 10mm loads because 10mm is so powerful, and the barrel is still like 3.8 inches.

The point I was making is, "that" is ill-defined without standardization. I wasn't asking to compare cock sizes with you.