Short pipe 1911s are the redheaded stepchild of the platform. The short stroke can create some timing troubles that are not apparent in 4" and 5" barreled guns and not all 3" models will be problematic. For those that are there are some simple fixes and tweaks that can make them every bit as reliable as their long legged brethren.
I bought a Super Carry Ultra HD for Christmas and it had some failure to feed and eject issues through the first 500 rounds or so. This is Kimber's state "break in" period, but there was a couple of things I did to insure that the gun performed 100%.
One of the things that make short barrels fussy is the cycle time. Given the same load, a 3" barrel cycles faster than a full size gun due to the lack of mass in the slide: a lighter slide will be driven rearward faster. Perhaps the single most effective adjustment I made to my Ultra was to install a square bottom firing pin stop. The square bottom makes the hammer harder to push rearward, thereby slowing the cycle. We're talking milliseconds here but it makes a huge difference to the little gun. These can be had from 1911 parts houses......bought mine from Wilson Combat.
Adjust extractor tension. The extractor in my gun was very tight out of the box causing a few stovepipes (again, related to cycle speed) and frequently tossed brass at my head. Simple to adjust with a little bending. I changed this one for a WC Bulletproof just because.......I'm sure the factory extractor was just fine but it did need some tweaking.
Polish the feed ramp! Unlike their larger brothers, the feed ramp on Kimber's Ultras is part of the barrel and is very easily polished to a mirror finish. The FTF issues in my gun would jam the bullet nose on this ramp, which Kimber does not polish on their builds. A little automotive polishing compound on a Q-Tip shines that ramp up beautifully very quickly. Not had a single FTF since I did this simple, quick adjustment.
With these few tweaks the gun has become 100% reliable with not a single failure to feed nor eject in the last 140+ rounds, from 230gr hardball range loads to Corbon +p 185s and 230s. Great little piece......I love this gun! Just can't decide which grips to keep on it!