Is there real workd differences between, 24 22 and 21 inch barrels? Definitive MV loss? Severely increased muzzle blast? Or do they all perform about the same

You'll lose about 40 fps for every inch you cut off. I'd run a 24" barrel myself...That's what my CZ550 American has on it and it's just about perfect for that cartridge...

I didn't noticed any greater muzzle blast from my 20.5" 9.3x62 than from my 24" 375 H&H shooting 270gr bullets at 2500fps. Both were more of a "bark" than a "blast."

I doubt you'll lose 40fps an inch, or, if you did, whether that would matter at all. If I recall correctly, Mule Deer wrote an article, or maybe a post, comparing a 24" CZ 550 to the 20.5" CZ 550 and the shorter barrel actually gave slightly higher velocities with some loads.

I wouldn't obsess about the shorter barrel.

To the OP: if you're really worried about the shorter barrel, get the 24" version so you can sleep at night. Perhaps there really is a practical difference. Perhaps there is also a difference between 10 and 15 Angels dancing on the head of a pin

Im more worried with things such as "pointability, and excessive muzzle blast as well as "whippiness". I have a 20 inch barreled 308 that I cant shoot well at all off hand its just to whippy off hand

Cut it to 21" and move 3 feet closer to the critter you intend to shoot.

Balance matters mo for me and as I've said before, I ain't never missed a shot and thunk 'Gee I would have made that shot with an extra 3" of barrel'

Again, it depends on barrel/stock etc.

Had a M7 with a 20" tube, MR contour that was too barrel light for me. Screwed on a sporter tube cut to 21" and it handles very well now.

I found my McMillan stocked 20.5" CZ 550 to be very pointable, mainly because the heft of the action and scope put most of the rifle's weight "between the hands" so to speak. It came up quick, pointed well, and came back from recoil quickly without the kind of "whip" I've noticed in Remington Model 7's and other short, light barreled rifles with similarly short, and light, actions.

I did not find the rifle in its factory Mannlicher stock to be as handy, though that is largely personal preference. Once it was in the McMillan--and I've had two of their stocks on the action, both the now discontinued AHR pattern and the new Sako Classic-like pattern (which is similar to CZ's Kevlar stock in its lines)--the rifle became much more lively.

Ive narrowed it down between the kevlar carbine and the 550 american with kevlar stock

Go short...

20" Douglas #3. Handles great with no whippyness. Even with the heavy laminated stock (I drilled some out) she weighs exactly 8 lbs with three rounds--my target weight.

The barrel band really keeps it low on my shoulder for walking through that dark timber, as well...

The less a cartridge is overbore (small diameter VS powder charge, like a 257WBY or 220 Rocket), the less a few inches of barrel length matters. Many of our really efficient cartridges - and the 9.3x62 is a VERY efficient engine - lose no appreciable velocity when cut from 24 down to 20 inches. I had a pair of Sako 222's once. One had a 26 inch bbl, the other had a 22 incher. The 22 inch barrel got HIGHER velocities than the 26 inch tube did. At some point it is more about how tight or smooth or rough a barrel is and the 222 is another one of those very efficient cartridges that just does not need a long tube to do its work. If a person had the money to buy and test five or more each of 20 inch and 24 inch barrels on the same number of 9.3x62 rifles, I would predict the velocity difference to be completely negligible and not statistically meaningful or measureable.

I just sold a 20 inch full stock CZ in 9.3x62 and REALLY WISH I could have afforded to keep it. Had to sell either it or my well worn but solid Model 71 Deluxe 348WCF so the 9.3 got shipped off today.

If I was healthy enough to go back into the dangerous game business, I would likely get my hands on another copy of that exact same gun again, modify it like I did my Current and well traveled CZ in 416 Rigby, and use that as my "older man's " big rifle.

Keep in mind as one reads the above, that I have been deer hunting with a 27.5 inch tubed 257ROY, did all of my dangerous game stuff with a 25 inch tubed 416Rigby, and my elk and black bear rifle is a 340 with a 26 inch tube. I love long barrels, especially on my rifles that burn lots of powder, but in my opinion one of the beauties of a round like this one is the ability to make a lighter, handier rifle that really can do it ALL, with aplomb.

My vote for a 9.3x62 is the 20 inch tube.

I put my first 9.3x62 together in 2000 for a trip to Africa in 2002. It was a rebore of a custom FN Supreme 30-06 with a 24" barrel. The barrel is fairly light after the rebore but the 24" length kept all in check. So I like lean and longer and would not settle for less than 22" in a light butted stock to allow a tad of muzzle heavy. That works for me in about every rifle I own.

In that chambering, I'd not fret over the velocity. Choose the rifle/barrel length based on rifle balance, fit and feel to your personal preference and needs. I am curious, however, did those Kevlar Carbines ever become readily available? I was looking to get my hands on one prior to getting my Sako 9.3x62 imported.

How the rifle balances and fits the shooter is more important than some fixed notion of barrel length.

My only 9.3X62 is a CZ FS with the 20.5" barrel. I have always liked the rifle and it shoots better than I can hold it. It fits me better now after modifying the stock a little last winter.

Consequently, I can now shoot it better off-hand than any of my other rifles; even though it has the most recoil. The stock dimension changes were minor but they made a big difference in perceived recoil and how it holds and balances.

(The day this photo was taken I had just shot it at water filled gallon milk jugs at 130 (paced) yards from sitting, off-hand and an improvised rest. Missed only once in 12 or 13 shots and the miss was from the rest. Load was 65 g. of Big Game in Graf brass, Winchester Magnum primers with the 286 g. Hornady bullet at just over 2400 fps.) I am a mediocre shot at best so was very happy with the day's results.