I had two FALs: one a Century L1A1 (piece of junk) and one ArgentineFMAP. The Century could not hit a pie plate at 50 yards. It also used to blow out cartridge case bases regularly- blowing all the rounds out of the bottom of the magazine, even though headspace checked OK. The Argentine was a great shooter, but terribly picky about ammo. Never found a load that worked 100% except South Africa stuff for the R-1. I sold it too, as I could not rely on it for a LEO trunk weapon. I had a CETME years ago and really liked the feel, but did not like the sights. I LOVE the PTR91 with the polymer Navy grip. Long trigger pull, but VERY smooth with a crisp let off after a slight staging of the pull.
As for IMR 4198, I love it for the 55 grain .223 loads. IIRC 21.5 grains duplicates factory 223. I am not worried about getting the extra 75-100 fps of 5.56 loads. I loaded 223 with it back in the 80s when all we had were 55s and lighter. I get 1 MOA on a good day.