As was mentioned a few times earlier in the thread... Get Loading Manuals
For my Springfield 1911 w5 inch barrel, I use the following for defensive practice and IDPA competition in CDP class:
Winchester 230gr FMJ round nose (feeds great)
Federal Large Pistol primers
4.5 Grains of tite group powder
167 power factor
726 fps average according to my chrono
That gives me a very functional practice ammo that has a gentle power factor of about 167. Right on the IDPA power floor. Its just a few feet per second shy of Winchester white box ammo which I chronoed at about 810fps. It functions well and is easy on the gun. I like the tite group because for one its cheap, works well on lower power loads, and it is clean. Not what I would use esp if I were wanting to do serious bullseye stuff, but if your doing defensive types of practice its fine.
If your wanting to cut tiny holes in paper, then you can try some of the recipies listed, but you may just have to experiment. Looking at the loading manual and powders/bullets available to ya, I find that the most accurate loads are the ones that fill the case with powder. In my chronographing experience the extreme spread on the bullet speed across a chrono increases as the empty space in the shell increases. I my hypothesis is that its an issue with the position of the powder in the case as the primer fires. Powder to the rear of the casing equals a slightly higher speed. Powder up in the front against the bullet equals a slightly slower speed. Just something I thought ya might find interesting.
If your new to loading be very careful not to
EVER double charge a casing by accident! As with many pistol loads if your not careful the casing will easily hold a double charge and ya can blow up your nice Kimber. Get a system down and avoid distractions when powdering and pressing. On my rock chucker single stage I powder and then press immediately so that if I get distracted I wont get screw up and charge it again... brain farts happen. Try to make sure that ya keep your focus on the job at hand and have a system.
My Dillon 650 progressive is what I load all my pistol ammo on unless I want some batch of just a few rounds for testing. Your gonna love your 550 when ya start using it as a progressive. Get the powder check system if ya dont already have it.
Another bit of safety info is that lead shoots faster and easier than jacketed ammo. That said, if you were to take a hot load developed for a lead bullet and changed to a jacketed bullet, your chamber pressure is gonna rise. Perhaps putting you into an over pressure condition. Keep that in mind with the hotter loads. Again... Look at the book
Here are some links that may help ya with supplies and equipment if ya havent already seen em..
Midway (loading equipment & accessories and bullets & brass ...)
Dillon Precision (presses and loading accessories)
Roze Distribution (great prices and free shipping on bullets)
Natchez Shooters Supply (powder, primers, bullets, ...)
Just a few thoughts... hope it helps. Be careful and have fun
BTW, if your at Fayettnam I have a cousin thats a Major down there that has a Lee 1000 progressive. He loads .45s and im sure if ya want some help or something he would probably be happy to lend ya hand if he has the time. He has been loading for years.