Maybe. I did a little test last weekend, I loaded some .223 that had been fired in MY BUSHMASTER AR. I used the lee collet NECK sizer, 4 die set from lee. The shells loaded, chambered, fired, and ejected without any problems. One thing I did NOT do is try to unload one that had been chambered but not fired.
This was winchester brass, not trimmed since the last loading, 24.5 gr. of benchmark, 60 gr. V-max bullet. Not looking for a group, not willing to wade through snow to get to the 200 yard target, just function testing, aiming at a clear spot on an old target. First time loading benchmark. Also first time using the lee FCD in .223.
Once we are finally rid of the snow, I'll do some accuracy tests with this die set-up in my new lee classic turret.
So my answer is maybe. Conventional wisdom says ALWAYS full length resize for ANY semi auto. Most times that's the right answer.