CFE223 Ladder from 25gr – 26.5gr. Max charge was my pick. Moved in .3gr at a time
CCI 450 Primer
LC 5.56 Nato Brass Annealed after every firing
OAL: 2.245\”-2.255\”, the meplate is a little inconsistent, as expected from open tip
CBTO: 1.895\”, this was consistent across my loading
Ring Crimped with Lee FCD
Using Criterion 18\” Core Bbl.
Average MV: 2919fps

My worse groups were at the lower end of my ladder testing. Worse group was around 3\” in the 25gr-25.6gr range. Things started to tighten up as I approached 26gr. Shot my best 10 shot group with a max Hornady load with their 75gr BTHP under 26.5gr. Got a little under .875\” with my best grouping. Other 10 shot groups under 26.5gr was slightly under and slighly over 1\” with my max being around 1.375\”. 10 shot groups are hard, even when using a sled so I could have been my technique. I still have more testing to do for consistency.

In my experience CFE223 performs best at max charges and honestly I\’ve only seen it get better past max if you\’re confident enough. I went all the way up to 27grs just to see what pressures would look like and see if I had a generous margin of error. Groups were around the same size as 26.5gr but I started getting raised ejector smears on the brass. No blown primers though.

I understand CFE223 is temp sensitive but I live in Hawaii so its pretty much always summer here and not too concerned.