How is 9mm recoil vs. .223 recoil? More or less?

Doggonit

You talking about carbine length rifles?  If so, 9mm has less recoil, but they are both very mild shooting. My 9mm can stay on target all day long though... rapid fire is pretty accurate for as fast as I can pull the trigger.

Yes 16" barrels, no compensator....

9mm is actually less recoil wise. The recoil is much shorter in motion than a 5.56 AR in the same bbl length. I have an RRA carbine with an a2 length stock, and no muzzle brake. You do not really need a muzzle brake for this carbine, because there is practically no muzzle climb. Also, if you did have a brake and an eotech or aimpoint sight this would be a good IPSC carbine class gun. It points naturally, and with brass cased ammo and some tinkering, can be made to be relatively reliable.

 It is not the most inexpensive project around, but the ability to shoot at indoor ranges and get more practice with your ar platform in the winter is worth the extra cost.

 Fit and finish on my unit are top shelf. If you are looking into getting an RRA unit, they are very nice.

I disagree.  

I have a [url=http://www.vzavenue.net/~eumenides/m16/RRA9mmflattop.jpg]RRA upper[/url] for my [url=http://www.vzavenue.net/~eumenides/m16/fake-80s-M16A2-Commando.jpg]M16[/url].  It bounces around MUCH more than my 11.5" 5.56mm upper.  There is more reciprocating mass, especially when using the RRA steel carbine buffer.  There is also much less muzzle blast for an A2 brake to take advantage of.
You may not notice it as much on semi-auto but after a few mags of each on full auto it's noticeable when switching back to semi-auto.

My 9mm upper is my favorite upper.  It's much less brutal to bystanders and when newbies want to blast a little, they're more likely to have a box of 9mm to give it a whirl.  9mm is much less likely to catastrophicly KABOOM my overly expensive lower.
Oddly, I get a lot less of "Is that LEEEGAL?" with my 9mm setup.

I totally agree with your last two points.

I think 9mm has more recoil. More recoil than nothing, let's be serious. Ar-15, .223, don't recoil they wiggle.

9mm is recoil operated with a heavier bolt. I think you actually feel the bolt/bolt carrier cycling.

Still very controlable, comfortable to shoot.

My 9mm Colt Carbine has more recoil than my 223. The 9mm bolts are heavier and are blowbacks as opposed to gas operated 223 caliber.

That's a good point.  We're really splitting a hair here.

With both my 223 and 9mm I've made the mistake of getting my nose to close to the charging handle while shooting.  From that perspective the recoil is much more on the 9mm.

"With both my 223 and 9mm I've made the mistake of getting my nose to close to the charging handle while shooting. From that perspective the recoil is much more on the 9mm."

That's gotta be a sholdering problem I shoot mine with my nose touching the handle and no problems- but I also snug it into my sholder or I would have problems.

[b]The difference between ramped and non ramped 9mm bolts will probably make this debate in-conclusive

WHO GOT RAMPED BOLTS?[/b]

Before I took the dremel and file to my bolt, there was a good bit of bounce going on during full auto firing.  
After ramping, it still bounces quite a bit but things are DEFINITELY smoother.  I wouldn't say there is a huge difference but it is more than a little different.  I didn't do the cut as severe as others have.  At a glance it looks very much like the 5.56mm ramp but on closer inspection, I've kept the rear shoulder a little farther away from the firing pin hole.  The closer that shoulder to the the center of the bolt, the more mechanical advantage there is for the bolt to cock the hammer.  That also means that the hammer is cocked more gently and the action reciprocates more quickly.

I'd say that if you use your Colt-pattern 9mm for more than occasional semi-auto plinking then ramping is worth it.  Of course if you're shooting an Oly this is a moot point!