Kind of strange. I've stepped up my charge (just shot some yesterday at 18.5 and today at 18.7 grains) and stopped seeing anything that looked like the occasional, light ejector marks I was getting at 18.3. Haven't seen any distinct changes in accuracy but my groups did seem to open up a little going from 18.5 to 18.7 grains.
I just bought a bunch of these. Cabelas had them on sale for $15 per 50 and also had a $20 off $150 rebate code offer on their website (shipping was free as I have them ship to the store near me). My most accurate/fast load so far is 18.2gr of H110 with a CCI450 primer, loaded to 2.085" OAL. It shoots under an inch at 100 yards out of my 16" barrel. I'm just starting to see very faint ejector circles once in a while at 18.2 while 18.3gr starts giving me some shiny ejector marks. Wish I had some chrono data I could give but my chronograph is giving me too many unrealistic numbers when I put supers over it. I really want to get my hands on a Magnetospeed...
Edit: And of course, after seeing the heavier loads posted (which I've seen before up to 20+ grains of H110), I'm going to jack the powder up and see what it does.
Don't blow your stuff up after reading my post. I am not a reloading engineer and I didn't stay at a Holiday Inn last night.