Buy and use cartridge headspace gauges, and don't get greedy for speed. And read the material at www.exteriorballistics.com/reloadbasics/gasgunreload.cfm.
DO NOT attempt to use practices such as neck sizing your brass - such techniques can injure or kill you if used in a semi-auto!!!
Who says he has to move out just because he's getting married
No, but seriously, I reload .223 and .308 on an RL550B myself. I don't shoot reloads in my M1A, but I do with my AR10. From what I hear the M1A is hard on brass because it extracts so early. If you reload it more than 4 or so times you may start getting head case separations and will need a stuck case remover. I haven't been there myself.
Check the reloading forum in the General area.
Also, I like AA2230-C powder because it's inexpensive in bulk and usable in both 308 and 223. Spambo and I buy it together so we can split the haz-mat fee.
+1 for Q-Man.
Buy 55gr FMJ bullets in bulk from MidwayUsa.com, PowerValleyInc.com or one of the there
other mail order companies. Prices vary.
Like Q-Man said, use surplus powder and spend some time working a good load using a
chronograph. NatchezSS.com, GiBrass.com or Wideners.com are good places to look for suplus
powders. WCC844 is what the gubmint uses for military ammo. Stock up while you can since the prices are increasing.
Also, I use the RCBS X-Die which limits brass expansion. You trim once to minimum dimensions,
champher, deburr, re-size and no more trimming. Just full length resize on subsequent loads.
I process the brass using a separate step so my decap/resizing station is empty when I prime, dump powder, seat bullet and crimp. I had problems with the 550 when using all 4 stations. It's my speculation that some of the ball powder I was using, stuck to the powder funnel which lead to inconsistent powder charges.
My $0.02 worth,