Newbie here
Loading 223 for an AR
Did two loads with the intention of fire-forming them so I could then size them down to a much smaller shoulder bump.
To my surprise, after I fired them, about half seemed to have barely any shoulder movement from fully sized!
The other half seemed to have expanded fully with a shoulder to head increase of about 14 thou (thats right about where this rifles shoulder is)
The two loads did differ in bullet seating depth, but were otherwise identical. It did appear the longer seating depth (with a bullet jump of only .020" to the lands), was higher pressure because the primers seemed much more flattened.
Unfortunately I did not keep track of which cases came from which load, as I was shooting them both at the same time and didnt anticipate this difference.
So my question is, can reasonable loads that act totally normal, not have enough pressure to fire-form the 223 case up to the shoulder from fully-sized? (fully sized being LEE die setup per instructions)
Both loads shot 1.5 moa and cycled the AR just fine, so they are not super low. They are not super hot either (21gn RL7 w/ 55gn FMJBT)