From my exp.
50gr Sierra Blitz = spectacular red mist and super accurate, my favorite .224 projectile but very hard to find in stock around here.
53 gr hornady V-max = lots of red mist, very accurate, easier to find than the Blitz and cheap (I know they are over your 50gr requirement, but man I love these they are my do all)
50gr Barnes varmint grenades = very long for weight, so so accuracy (MOA or a little over) inconsistent fragmentation, I've had a few exit. I have not tried the 36gr grenades but will soon.
Edit: just read your last reply. The 50gr Barnes varmint grenades will not work in your 14" twist. I would try the 36gr grenades.